If you have any questions you want answered, feel free to drop me a note. If you’ve got a question, chances are, there are lots of others out there with the same question. So ask away!
Note: all comments are moderated unless I’ve approved one of your previous comments. Almost everybody gets thrown off by this, but I moderate comments to avoid spammers. The downside of this is that you won’t see your comments post until I’ve had a chance to review and approve them. Sometimes this can take days (sorry!) Thanks for your patience.
Ted's Energy Tips 
Hi Ted,
We had two dual head AC/HP units installed last July. One has 9K and the other 12K indoor evaporators. What is this condensation pan that needs to be cleaned so scum doesn’t build up? Is that in the outside unit? My heating guy said he’d advise a tune up every two years. Would that be something he’d better do. I can handle the filters easily but perhaps this condensation pan is not easily accessible. The thought of problems in the wall down the road though made me want to ask.
Please describe maintenance on condensation pan. Thank you. Have a good holiday.
The specifics will vary depending upon model. Your best bet is to have your heating guy do his regular service and ask him when he’s taking the cover off so he can point out exactly where it’s located. Sometimes taking the cover off can be tricky (hidden screws) so it’s best to watch someone do it once.
In addition to the condensate pan, you’ll want to vacuum off the blower wheel which can be hard to access. My guy chastised me last time he looked at mine because it had a lot of dust on it!
Thank you. I’ll do that.
We have lived in our house for 15 years. This is a 28×70 modular home. This summer we tighten up our home with new Windows’s and siding . Everything was sealed up and has been fine. Now one room in the house has an odd smell. It smells like dirty, musty shop rag. The odd thing the.strongest smell is about 2 foot into the door of the room . This is located right next to a bathroom but that smells fine so didntvthink it could be sewer gas. Any suggestions?
You become more aware of odors when you tighten a home because the smells can linger around and build up since there’s less air flowing through the house. This is especially noticeable in winter when very little fresh air circulates.
Locating odors can be very difficult. They can get caught by an air current and build up elsewhere. Also, odors can come up through cracks in the floor, making the source even more difficult to find.
It is possible that an animal died under the house. This happens to me at least once a winter when field mice get into the house to get out of the cold. That smell can be like the one you describe.
You’d probably recognize sewer gas – I think we all know what that smells like!
It might also be moisture buildup and mold growth. Often the only way to find that is through visual inspection. If you have access under that area of the house, great. Otherwise, it can be very difficult to inspect.
If you have access under the house, you could shine a flashlight or explore under there if you have enough access. Access may not be possible, in which case, you are probably out of luck. When I’ve had issues like this, I’ll turn on a nearby bath fan, and let it run continuously, drawing the stale air out until the odor is bearable. If it’s a dead animal, it can unfortunately take weeks for the odor to get better.
hey ted , bruce here, spoke with my hvac guy that i used for my cottage. we went over some numbers and he felt the costco rep should have measured the house and checked attic to properly calculate heat/load numbers.he also said his company could do the job even if it is a bit of a ride for them . he was about 600.00 higher for same setup because of the costco rebates that he does not get. they do 15 months zero % financing which is nice to ease the 8000.00 out of pocket in one swope the other way. he did recommend a amana unit for about 550.00 lower then the lennox . he claims they have lifetime replacement on condensor for a much better warranty . does the copper on the lennox justify the extra cost . costco sales guy stated much better because of the copper on the condensor. any thoughts on the copper versus alumminum parts if the amana will replace lifetime anyway , does it matter. i am leaning to lennox but my wallet is leaning to amana with lifetime replacement as long as the brand is not asking for trouble
Be wary of thinking that lifetime replacement means at no charge. I just went through this with my Mitsubishi mini split – it was leaking and even though under warranty, it didn’t cover labor which would cost as much as the unit! But that’s a story for another day…
While heat loss calculations are great when starting from scratch, I personally find the best results come from knowing the characteristics of the existing system and determining the real load of the house. I measure the run times at various temperatures to determine the load curve. That’s hard to do this time of year so you’d have to work from memory. How does the system keep up with demand on hot summer days? Not the hottest days but typically hot. Based on that you can make a pretty good estimate of the requirements for the new system.
All that said, it seems like you have a good relationship with your HVAC guy. If you think he does quality work and you trust him, then stick with him even though he may be a little more. My attitude is once you find an HVAC company that does quality work, keep working with them.
As for copper vs. aluminum, copper can be more durable and has excellent thermal characteristics but it all depends on the details. So I’m afraid that I can’t say anything useful on that front.
Hi Ted, I have a question. I have a house that is about 60 years old . I have been living here for 22 years. Last month an unusual odor somewhat of a chemical smell started in one room in my house. It came out of the vents when the heat or ac was off I called a heating specialist and he says it wasn’t from the heating unit. I had the vents cleaned but still didn’t help. Now I smell it sometimes in the room below on the first floor but not as strong. Its definetly something in the vents but I can’t identify it? My husband went into the attic and on the roof but couldn’t find anything? We are perplexed and worried because it is a strong odor . Any ideas?
hey ted , he felt in the old days that most systems were oversized and does not help with the humidity as well as causing system to cycle on/off because you heat up to quickly and dont create any radiant heating which then shuts the stat down and then needs to cycle on again in a ineffeciant manner. i always felt the upstairs was colder then main floor that has high ceilings, he felt that was more of a damper issue and was very confident that 3 ton was needed . ” i have done many homes in this area , this style and so forth ” he did not even take out a tape measure. we looked at my old unit outside , he saw model number and went right to a 3 ton unit without any hesitation. even a fake measure would have done the job. . how does my pricing look to pull the trigger, i was really just fishing in case the system did not work the coming summer. should i replace before the actual doomsday on a20 year old system that owes me nothing .i have been saying one more summer for the last three summers already. thanks bruce
Given all the incentives and rebates and such that you’re getting that sounds like a reasonable price for a high-efficiency system replacement. It’s certainly not out of line with prices that I’ve seen elsewhere. I would certainly replace it sooner than later because the last thing you want is to have to buy something in an emergency situation. And as you noted the old system is definitely long in the tooth
In reply to Bruce… Did your existing system cool effectively? 21 years is pretty good out of a DX system, so seems like it was probably sized correctly (not short-cycling). I only ask because I design commercial hvac systems, and we do a lot of replacement work where our load calculations will say the system can be smaller than what’s existing, but if the existing system worked well for X number of years and the occupants were happy with it’s performance, why risk putting in a smaller system and not having enough capacity? A lot of residential hvac guys will do a cut-and-dry SF/ton calculation, but did he take into account your high ceilings? High ceilings = tall walls = more heat gain. I’d just ask him how much extra it would be to stick with a 3.5 ton, and see what his reasoning is for wanting to go smaller.
Thanks for adding that information and perspective. I missed that they were changing the system size and totally agree that if it’s worked for years then don’t mess with the size unless it was obviously short cycling
hey ted, hope all is well. you helped me a couple of years ago with deciding on a system for a cottage s heating /cooling needs.. i now am looking to replace a 21 year old lennox 3.5 ton system in primary home.thru costco , the rep came and reccommended a lennox 3 ton unit , leave my existing flexible black tube duct work . he is offering a xc14-36 and compatible air handler ,16 seer rated honeywell vision pro 8000 wifi stat for 9500.00. costco gifts back a 675 money card pseg rebate of 700 . for winter install , 500 off as well from company. using costco visa to pay for job gets another rebate of 260.00 plus a tax credit for 300.00 . . grand total is 7365 for job if i do it within a few weeks. i did not include the 300 tax credit in that number. i was thinking of adding heat pump for supplemental heat , he did not think i would be happy with it since i have a split level with some areas of high ceiling and such. that was a 900 addon . hthe salesman feels rebates will lessen after january and the 500 discount from them as well for off season work. your thoughts would . be helpful. thanks all the best bruce
Hey Bruce good to hear from you. My house has high ceilings in the main room and heat from the heat pump definitely pools at the ceiling however I still find it useful for a general heating purposes. If you have already have a baseboard heating system then I don’t see how it could hurt having the heat pump capability especially since you’re getting a good deal on the package with all the rebates Etc. Again, it’s not perfect but what heating system is? And if it’s only supplemental you’ll probably appreciate being able to use it in the shoulder months instead of whatever other heating system you have which is probably fossil fuel.
Will partially insulating attic rafters help with energy costs when the attic floor is already insulated? Here is what I got: 2500 square foot home in climate zone 4 built in 2006. Typical 2 story light frame construction on crawlspace. Stick built roof with 12/12 pitch, fullvent vinyl soffits, gable vents at 4 gables and no ridge vent. Attic floor out of 2×10’s with blown in insulation in most locations except R-38 batts beneath 1/2″ sheathing for storage area running along center area of attic. Upstairs heat pump and ductwork in the attic and not within thermal envelope. Would like to bring both somewhat into envelope and make the space more semi-conditioned. Was thinking of running baffles and either R-13 or R-19 in the rafter bays and framing below the gable vents to make the space less susceptible to large temperature swings but not finishing with any type of drywall or air barrier. Rafters are 2×8’s so there would be space for air to still move even if I don’t do the baffles from soffits to gable vents. Figured with the space at least insulated but not air sealed it would be less work on the HVAC plus keep items stored in the attic from the extreme heat of summer and cold of winter and hopefully not cause any moisture issues because it is not air sealed. Would still leave existing ceiling insulation and air barrier as is. Would such a move be beneficial or pose more problems than good? Has this ever worked in my climate zone?
Thanks for asking – attic insulation is the hot topic this year, so I’m working on a series of articles specifically to address questions like yours. The first of the series is here:
It sounds like you know your stuff, so I won’t belabor the basics. If the goal is to help the HVAC from being stressed to the attic extremes your idea might work well. While I’m always leery of “double insulating” due to the potential for moisture problems under the roof deck, it sounds like your attic is amply ventilated and you’re taking care to avoid “dead air-spaces” which is needed to avoid moisture buildup.
You might try using radiant foil under the rafters. This is one application that I’ve seen work quite well (I installed it under my roof sheathing in my garage attic). It dramatically reduces summer heating as the radiant barrier is very effective at reducing radiant heat transfer from the super-hot roof sheathing down into the attic space. This would be much easier and less costly than a full insulation job. It would not however help the cold of winter. However, with a well ventilated attic, no insulation will help keep the attic warm in winter.
Hi Ted,
I have a question about insulation.
I have a 115 year old Victorian row house made entirely of brick. In our basement (it’s more like garden level–a few steps down), my contractor is installing a shower. He framed the shower against the brick, then insulated it with a rigid board insulation called polyiso. On top of that he installed durock. Then he will follow the proper procedures for tiling.
Does that sound ok?
I read your post being careful about condensation behind walls.
Is the other side of the wall in the dirt or exposed to the outside cold temperatures? If the brick has voids which can fill with water, then allowing it to get below freezing for extended periods can cause fractures. Before insulating, the brick was warmed by the exposed face in your basement which would greatly reduce the potential for problems.
I’m not saying that insulating it is necessarily a problem. Much of it depends on your climate and the exposure of the outside of that wall. People will often insulate the inside of cinder block walls that are underground because the earth helps shield the foundation walls from temperature extremes. So it really depends on your specific situation and the exact construction of the wall.
As a follow-up – here is a very detailed document about freeze-thaw damage that include maps that indicate how much concern there is. I’d highly recommend browsing this and perhaps giving a copy to your contractor who might want to keep this in mind for his projects.
Thanks for your feedback Ted. Are you also familiar with Gree minisplit systems?
Unfortunately, no. Only heard of them but never seen in person.
Hi Ted,
We’re planning to install a ductless minisplit system in our Brooklyn brownstone. Planning for 2 units on each floor (2 floors total). We’re hoping to get a system that has cooling/heating/air cleaning/humidifier in one. I’m not sure if this exists all in one system. I know it’s typically cooling & heating. Are there any brands/systems you’d recommend? Thanks so much!
Never heard of a combined unit of that sort. Though for this application, you’re best off with a standalone humidifier or two.
As for filtering, each manufacturer has their own special air filter that will do basic filtering. Though if you have special needs, you’d probably want to get a HEPA air filter, again standalone.
As for manufacturers, Mitsubishi tends to make the “workhorse” units, that most installers can service and support.
Be careful of who you hire to do the installation. Ensure that they’re factory certified by Mitsubishi. These new units are very high tech and I’ve had them stump even highly trained technicians who lack the specific Mitisubishi training.
Ted,
I recently bought a Mitsubishi Mini Split with four heads. A persistant problem has been one port not cooling the connected head. We interchanged lines from different ports to verify this. Another problem is one head while turned off seems to have freon running through it enough to produce dripping condensation from the vent blades. The installer changed computer board with no improvement, Any ideas?
Perhaps the distribution valves are malfunctioning? I am not familiar with the internals of these units but I have to imagine they have some electronic control over the refrigerant flow to each head. One could be stuck closed and another stuck open
What type of radiant insulation barrier was installed in the 1950’s in the walls and attic floor. Can you just put cellulose over it after air sealing the attic floor or should the barrier be removed prior to adding the cellulose?
I’m afraid I’ll have to take a pass on this one. You’ll have to get a local expert to take a look at it and advise you as appropriate. Typically these will act as vapor barriers so you should treat it accordingly.
Ted,
Working on wrapping up some attic insulation before the winter hits here in Michigan. I was thinking about putting rigid insulation on the bottom side of the roof about half way up, to in essence, create a giant baffle, instead of the individual baffles in each rafter bay. This is considerably harder than the individual baffles, but does it provide any benefits that you can think of?
Much Thanks!
Andy
I don’t quite understand what you mean by “half way up”. Do you mean half way inside the rafter bay so as to make an air channel under the roof sheathing?
You could do something even easier – mount large sheets of rigid foam to the bottom of the rafters (imagine sheetrocking a cathedral ceiling, except using foam). You’d then have the great insulating capacity of foam board, plus the moisture barrier (if it’s sealed properly and runs from soffit to ridge). Plus, it greatly reduces thermal bridging since there would be no cold beams exposed inside the attic. If you wanted even more insulation, you could put batts between the rafters, leaving at least an inch or two between the batts and the roof sheathing. Then put foam as described. This would be a nearly ideal attic insulation as it provides roof ventilation, good R-value and moisture protection. Plus, it will leave your attic vastly more comfortable if you need to go up there in the summer.
Ted,
When I said half way up, I meant halfway from the soffit to the ridge. But we are on the same page. I meant attaching large sheets of rigid foam to the bottom of the trusses. I only suggested “half way” because I assumed I would want to leave the top half open so that any moisture that may make it’s way into the attic could still exit via the ridge vent. I apologize if I misrepresented my setup. I do not have rafters, but 4/12 trusses.
Thank you!
Andy
Oh I see thanks for the clarification. Trusses are certainly a challenge. If you could seal up the inside on the bottom of the trusses using the sheets of foam board you probably have a pretty good setup. The only thing I would worry about as far as moisture relief is that you allow free air Passage behind the foam board from the soffits up to the ridge vent. But I wouldn’t leave a space so that air can flow from the inside of the attic to this new space under the roof. That’s actually likely to cause more problems because you’ll be essentially sucking moist air out of the house
The truss bay would be completely open from the soffit to the ridge vent, all my insulation is currently and will be on the floor of the attic. You don’t think I should be concerned with any moisture that may migrate into the attic being able to exit the structure somehow, normally via the ridge vent? I will try to air seal as best as possible, but it’s hard to get all the nooks & crannies in an old house.
Sorry I think I’m being dense today. If all your insulation is on the floor and you have a ridge vent then won’t the air flow from the attic space up through the ridge? I thought you were talking about foam board directly under the trusses, not on the floor. Or are you talking about insulation on the floor and above it?
I was inquiring about putting rigid foam board on the underside of the trusses, but not the ceiling of the living space below if that’s what you were thinking. The “underside” being directly opposite the roof, as if I were drywalling a cathedral ceiling as you described it. I thought I read that you said to continue the cathedral style rigid all the way up to and including the ridge vent, essentially separating the underside of the roof from the attic space. Did I misunderstand you? If the soffit to ridge vent space is completely sealed, how would any moisture that migrated into the attic from the living space escape? You mentioned there being free passage in this soffit to ridge vent area behind the rigid foam, and there would, it would be empty, no insulation.
I hope I’m making sense.
Andy
Ok, that’s making more sense except for the part where you said: “all my insulation is currently and will be on the floor of the attic”
If you’ve got insulation on the floor of the attic, why put foam board under the trusses, like a cathedral ceiling. You must only have insulation in one location. If you have foam board (insulation) under the trusses then you need to take up the insulation on the floor. If you have insulation on the floor, you don’t want foam board under the trusses.
If you have both, you’re creating a cold, dead air space and, as you noted, this will be prone to moisture problems.
Ok, we’re on the same page now! That was my concern, creating a dead air space in the attic if I fully sealed with rigid. I do currently have insulation on the floor. I’m in the process of air sealing and adding more. I was thinking of using the rigid more as a big baffle, instead of the individual baffles in each truss bay. But it sounds like I should stay away from any rigid and just add additional fiberglass.
Thank you!
Andy
Ted-
Hi I have really enjoyed reading the above question/answers and I apologize if you have already answered this question–but I am in the middle of a kitchen renovation and am suddenly freaking out. I have a two story house was built in 1924 with plaster walls throughout and cedar shingles on the exterior. My main kitchen wall is exteriorly exposed with freezing cold constant drafts in the winter. I currently have the backsplash exposed so that I could update wiring/plumbing and I was starting to apply insulation. However, I then started reading online about all the problems with mold and wetness and now I have no idea what to do. I am afraid of creating more problems and have stopped everything. I would have to completely remove the bottom cabinets in order to install vapor barrier between the framing (I had thought of just stuffing cellulose down between the framing) but now I am think maybe no insulation is better?? Additionally, there is a crawl space under this half of the house and it is completely dry and sandy. Is there anyway you could help advise me?? I can send pictures if you want. I just graduated from college and am doing this myself so I am trying to keep things from becoming crazy expensive, however I want it done correctly and will pay for something to be done the right way. Please help.
Hi Laurel, I understand your fear. The home is the most complex “system” you’re likely to work on – it makes tinkering with a car seem easy! And yet few people are like you and understand that there can be many unintended consequences when doing work like this.
One important factor when considering renovations is where you live. Your IP address indicates that your ISP is located near Tulsa Oklahoma, a moderate climate zone 4 with average winter temperatures around freezing but not super cold. Does this sound right? (here’s a page on climate zones)
The deal with condensation (in winter) is the colder your climate, the more care has to be taken because the coldness can cause the moisture in the air to condense. So water vapor from in the house can move into those wall cavities, through the insulation and condense on the outer wall before the water vapor has a chance to escape. So you do need to be careful about blindly shoving insulation in there. On the other hand, building scientists have found that, in many cases, using vapor barriers causes more harm than good unless you’re in an extreme climate, which you’re not.
You mentioned drafts – in many cases, the drafts, caused by outside air leaking in through cracks or holes in the wall, causes more cooling and energy loss than poor insulation. So one really important thing is to locate where the drafts are coming from. Related to this, it’s easy to forget that those drafts work in both directions – air from inside the house can leak out those holes/cracks and into the walls – this often causes a lot more water damage that would be experienced from the lack of a vapor barrier.
Every area has its own rules about vapor barrier usage. Those rules are usually determined by what’s best for the climate. I would encourage you to ask your local building official about their recommendations. They shouldn’t be necessary there, but when in doubt, follow local building practices.
As for insulation, some people have insulated these types of walls with cellulose with no adverse effects. Largely, it’s a matter of how much water vapor can get into the walls from inside your house. Do a good job sealing the inner walls then you’re less likely to have problems. Very few problems in moderate climates come from vapor diffusing through the walls themselves. Again, the problems are usually due to exceptionally high interior moisture or poor construction that allows air to flow from inside into the walls.
That being said, when I remodeled my kitchen, I was horrified to see what was behind the cabinets – the previous contractor had literally bashed holes through the walls (exterior walls like yours) to run plumbing and electrical wires. If you’ve got big drafts, there’s a good chance that you’ve got the same type of issues behind your cabinets. You’ve only got one opportunity to pull the cabinets without too much disruption to your life, so if I were in your shoes, I’d remove the cabinets and check the walls. This also gives you the opportunity to remove the sheetrock (hopefully it’s not still plaster walls on the inside because that’s really messy!) and insulate the interior of the walls properly. Then you can seal up the walls properly and eliminate all those drafts while at the same time greatly reducing the likelihood of moisture problems in the walls.
So, in sum:
– check with local building officials to find what’s recommended or required where you live (this should be step 1 for any renovation).
– pull the cabinets while you have the chance so you can inspect all the exterior walls for holes/drafts etc.
– if possible, take this opportunity to insulate
– close up the walls paying attention to details so inside air can’t get into the wall cavities.
One last thing – if you have pipes running through exterior walls, be very careful! If you add insulation to those wall cavities and place the insulation inside the pipe (i.e. the pipes are closer to the exterior walls) you run the risk of pipes freezing. You only want insulation behind the pipes (between the cold wall and the pipe).
Hope this helps.
Hello,
About two months after moving in to our home (1964 ranch) I started to smell an earthy smell in the only room we have on a slab. The rest of the house is over walk in crawl space. I investigated further and noticed the smell coming from the baseboard area. We had a blower door done shortly after for audit reasons and air was pulling strong from the baseboard, along with it the smell. I took the baseboard off and the smell was there, but no signs of mold or moisture. I pulled the flooring (laminate on thin vapor barrier) and no signs of mold or moisture here either. I poked a 3 inch whole in the wall just above the bottom seal plate and still nothing. But there’s a strong earthy smell. I’ve had several folks come out and none of them know how to approach this. In my mind if there is a moisture smell (wet dirt, earth, moldy) there has to be a problem somewhere.
The house has really big eaves so rain does not fall next to the foundation. It doesn’t puddle there either. It’s graded away from home. Plus the slab floor is about 7 inches above grade. The exterior of the home is granite stone veneer about 4 feet up and then wood. It’s insulted with bats. I see no vapor barrier in the wall. Any suggestions about this. If nothing else, any suggestions on the type of person to call? It’s a kids playroom so I’d like to get to the bottom of it. Thanjs!
I think you have figured it out. Since there’s air leaks around the baseboard, air is getting sucked in there from the outside. Any odors around the perimeter of the slab will enter your home.
I have a similar issue around the baseboard of my living room area. During the winter, I could feel the cold air pouring in! So I got canned spray foam with the long straw for getting into nooks and crannies. I then carefully (since it’s very messy) went around the perimeter and filled in all gaps. Problem solved.
If the baseboard is accessible (mine has heating convectors), then you would want to use caulk to fill in any small gaps.
The giveaway at my house was when I got on the floor and examined the transition between the wall and floor, I could see a gap, since the drywall was cut back when they installed the wood flooring. That was open right into the wall cavity. Where I didn’t have baseboard heating, they put a piece of quarter-round moulding. I pulled everything, sealed it up, then replaced the moulding.
I’m pretty sure if you do this your home will smell less and be more energy efficient. It will also provide fewer gaps for ants and other critters to enter your home.
Hi Ted thanks so much for the reply. It’s funny you suggested that because it’s exactly what I did. I spray foamed the the gap under the drywall. But the smell is still there. I was sure this was going to solve the problem. But, as a matter of fact, after the smell of the foam wore off a bit the earth smell was worse. Any other suggestions? I’m totally stumped.
Darn! I was certain that would be it. It sounds like you need more analysis with a thermal camera to determine exactly where the smelly air is leaking into the room. From your description, it seems impossible but there has to be something that is allowing the outside air to get in.
BTW the thermal camera will also show if there’s an anomaly in the wall insulation that could be caused by a water leak in the wall. From your description, it’s unlikely but I would not rule anything out. I had a wall rot out that took a long time to discover but it would have been easy to find if I had a thermal camera at that time.
Hi Jim, one more thought – sometimes rotting walls can smell “earthy”. I remembered that my kitchen wall had a slow water leak in it from the previous owner’s renovations. We had no idea that there was any issue. But one Christmas, I became concerned because we kept hearing loud settling noises. This is an old house so it shouldn’t be settling! Long story short, I discovered that my kitchen sunroom was improperly built and the wall framing had completely rotted out. The odor was distinctly earthy, probably because of all the critters that were living in the moist timber, eating it and turning it into dirt!
Even though you said you couldn’t detect any moisture problems (either could I at the time), you might go around the room, tapping on the wall near the floor (since water runs down, it usually causes rot at the bottom of walls). Tap-tap-tap listening for any change in pitch as you tap around the perimeter of the room. Check for any discoloration or different feel to the wall. In my kitchen, I was able to poke my finger right through the wall! The darned people who sold me the house had painted over the discoloration.
Wanted to pass this on. Hope this isn’t the problem you’re having, but it’s good to check everything.
Hi,
I tried to post a previous comment, but it appears to have gotten lost, so my apologies if this is a double post.
We live in a 1925 bungalow that was remodeled and added onto in 2014 – when we moved in. It has a semi-attached garage – the back door of the house leads to a covered patio, then to the garage entry door. The garage door faces an alley. When we moved in, the alley was dirt that turned into mud every time it rained, so we were tracking in a lot of mud with our two cars. About a year ago, we had the alley behind our house “paved” with crushed limestone. The garage itself smells like “home depot” – or a mix of dirt and fertilizer, which we do not store in there.
When we leave the house, we find that our clothes, luggage (and purses), and cars (the strongest) smell like something related to cigarette smoke – but not that precise smell. We do not smoke and no one we know does.
We have had a mold air test done in the house – the only mold found was lesser amounts of the same type that was in the outside sample. There are no visual signs of mold and that’s not really what we are smelling. We had an air duct cleaner company come out and tell us there was nothing to clean – so they ran a fogger through the HVAC system just to see if that would help (it didnt)
We had ServPro come out and they just suggested that we clean out the garage, seal the concrete and do an ozone treatment. They are not sure what the smell is. He suggested it could be dirt in the garage that we didnt clean out of the concrete or some unidentified chemical? We have no idea.
Thinking about having a different air quality tester come out – any ideas??
No one in the house is sick, but we just want to figure out what’s going on.
Thanks in advance!
No problem. I have comment moderation turned on to avoid spam posting.
Is there a reason why i shouldn’t use R30 compressed fiberglass insulation made for cathedral ceilings in the attic’s floor? I have only 6 inches of depth available and i want to preserve as much space between the floor and the roof as possible.
I don’t see why not. I haven’t seen the product before and Googling about it didn’t reveal anything other than sales information from the manufacturer. However, you might consider insulating under the attic roof instead of on the floor. This gives you the advantage of a much more comfortable attic space where you can also have free access to the attic floor for wiring or other work you might need to do in there. In addition, the product you mention appears to be at least 10″ thick so it still may not be the product you’d want. Even so, if it’s giving you additional R-value per inch, it may be worth considering.
You may also want to check out another specialty Dow high density fiberglass product – R21 fiberglass for 6″ walls
Hi Ted,
Thank you for the quick reply. In regards to R30 compressed insulation, it is 8,5″ thick (https://www.google.com/search?q=r30c+insulation&ie=utf-8&oe=utf-8)., so it will work for me partially…
I am about to spend my first year in this house located in Maryland I bought several month ago and I am trying to learn about it as much as I can, and you advises posted on this site has been very helpful. The house was built in 1946 and it is a brick house with plaster walls and nothing in between them. This summer it was pretty hot insider, considering there is no central air. The attic was also extremely hot, so I couldn’t really look at it until now. Luckily the roof is brand new, and there have not been any leaks.
So, the reason why I am not insulating the roof is because I cannot figure out how the attic is being ventilated. There are no soffit vents but there is a ridge vent and a window. So I assume the air gets into the attic from the space left between the walls and the plaster, which does not have any insulation in between…So, I am not really sure what I can do to avoid any kind of damage to the roof in case I am going to insulate it. I also want to mention that I have gable roof and the ceiling on the 2nd floor is slopped…so I am afraid to stuff insulation there without understanding the attic’s ventilation.
Meanwhile, I am tearing the attic apart as it was previously nicely covered by wood (floor + knee wall), so I can seal all of the holes to prevent air leaks. The existing insulation will be removed. It is some black looking fiberglass that falls apart as I touch it. Also, it is about 3 inches thick so it needs to go. By the way, I am not sure if the knee wall structure was there for support or for esthetic design. However, considering how poorly it was nailed down and attached to the floor I would say it was not there for support.
So, what I’ve decided, and it might sound silly, but I want to cover the floor space with R21, and behind the knee wall and in the sloped part of the floor I want to put R30C. The 2nd one will work for me because the space will not be used to walk on, therefore thickness is not so much of an issue.
I also read someone’s comments in regards to putting plastic sheeting between the floor and the faced batting for extra vapor protection, have you ever heard of something like that?
Any thoughts on anything I wrote so far?
You general comments are highly appreciated. Thank you
Your plans seem to make sense. It will be challenging to get the house comfortable with the uninsulated brick and plaster walls but as you’ve seen, those walls are not easy to fix. So the attic is the best place to start.
I like the idea of pulling the existing insulation and air sealing before insulating. And you are wise to avoid filling the slope with insulation since that can lead to roof rot if an air space is not left between the insulation and the roof deck.
If you can get R30 in there or close to it, you’re 90% of the way there. That should make the upstairs below the attic much more comfortable compared to a few inches of old insulation.
I’ll read through the link you sent and add comments if anything concerns me.
After looking at the R-30c insulation I see that it performs well at that thickness but Interestingly, if you can get regular R-38 insulation and compress it to the same thickness, you get R-32. Point being, it will depend on cost since the C insulation is more expensive.
Also, you asked about plastic – in Maryland, you don’t really need to go overboard with vapor retarders. The craft facing is plenty especially if you carefully air seal before insulating.
Thank you Ted, I did find the source. Like I said it was from the dishwasher. Because I removed everything and the drywall is molded only the bottom half.
I do still would like to know what kind of insulations you will recommend.
I have completely remodel the whole kitchen that includes drywall, electrical and plumbing. Now the next steps is insulation. I will need your recommendation as to what type of insulation best for the kitchen.
Thanks for the clarification. I didn’t realize that it was definitely the dishwasher. Glad you found it.
In your very cold environment, controlling moisture movement into the walls will be very important. The basic idea will be to block the moisture on the warm side of the wall – i.e. closest to the inside of the house. That’s why there was plastic in there. Then, the insulation. The common, but imperfect solution, is to put fiberglass in the walls with the vapor retarder facing inward towards the kitchen.
The thing to keep in mind is that any moisture that is able to get past the vapor retarder and insulation will then come in contact with the cold outer wall of the house – usually wood sheathing. The water will condense and, in the winter, probably turn to ice crystals. Sometimes, it might melt and sometimes it might just keep building up as more moisture gets in and freezes. The important thing then is to minimize the amount of moisture that can get in there and if any does, allow it to dry out. The wood sheathing will naturally let moisture pass through it slowly. This process can continue for decades if it is slow enough.
If I lived in MN, I would definitely want to spend the extra on closed cell spray foam for the walls. This is both an insulation and a very effective vapor barrier. Because it sprays in and gets everywhere, it is much more effective than plastic and fiberglass. It will also protect the inside of the wall from moisture that might get in through outlets or other sources inside the house because that moisture will always have to be on the warm side of the insulation.
That sounds like quite a mess – sorry to hear about your situation.
The first and most important step in remediation of mold is to find the source of the water leaks so you can fix the right problems. If the kitchen walls are moldy too, maybe the water is coming in from above and leaking down the kitchen wall and all the way to the basement.
If it was my home, I would remove a vertical section of sheet rock (like from one stud to the next) from floor to ceiling. Then inspect to see how much mold is there and where it starts high on the wall.
It might be coming from above, like maybe from ice dams. Or there might be some other source. Really critical to find it.
Also check if it is wet now or if the mold is from old leaks like from last winter.
I can’t stress enough how important it is to track the leak. If it keeps happening, it will lead to structural damage.
After that is resolved, you can think about insulation!
Thank you very much for sharing your knowledge on this site. Your posts are extremely helpful, especially for a first time homeowner like myself who knows relatively little about home energy efficiency, home repairs, etc. I live in a 1940’s split-level ranch home in the Mid-Atlantic. Last year we hired an energy audit company to come in and survey our home to see how we could cut down on our monthly energy bills. We learned we were light on insulation in the attic and that we have no insulation around the perimeter walls of the house. When the company came in to put new insulation in our attic, they quickly halted the job because they found evidence of vermiculite under the fiberglass insulation we currently have. Long story short, for our peace of mind and re-sale in the future, we would like to remediate the vermiculite problem. We’ve brought in a licensed asbestos contractor to present us with a plan to remove it safely. The company does not believe there is a lot of vermiculite left (they think a previous owner may have tried to remove themselves), but we will still need to follow protocol to remove. Post remediation we need to have new insulation put in our attic. The contractor has recommended we use a spray foam to encapsulate any potential remaining particles that could remain post remediation. This is where I am stuck and would love to hear your thoughts. In theory, the spray foam sounds like a great option, but upon learning more about it I am really concerned about the chemical/petroleum contents in the foam. As I’m researching, I keep reading horror stories about the off/outgassing of the product as well as its flammability. Per your website I learned of additional types of insulation, including the soy foam spray. At first that sounded like a great and greener option, but after further research it still sounds like a majority of the product is petroleum based. Then I read about the cellulose options, but am thinking that may not be a great idea especially if it is messy and kicks up particles. The sprayed-in Spider fiberglass sounds like a great option, but from what I understand it is for spraying in the upper/roof part of the attic and not the attic floor, where we currently have our insulation. If this were your home, what type of insulation would you choose? Also, is there anything we can do about insulating our perimeter walls (where I’m sure some vermiculite has trickled down) without a demolition job? And one last question, would you insulate our utility room on the bottom floor, which has no formal ceiling only beams and wood flooring from the floor above it? Our HVAC system is located in the utility room, and we have seen a few rogue pieces of vermiculite trickle down from the attic to the utility room from a perimeter wall. Thank you for any advice you are able to provide!
You’re welcome! We’ve all been there, trying to learn new things and being deluged with often conflicting information. Home ownership is perhaps one of the most complicated tasks that any of us will have to deal with in our life since it’s so multi-faceted.
Vermiculite in our region is indeed a red flag. Though not guaranteed to contain asbestos, much of the product did contain it. It sounds like you’ve done your homework, so I only mention this for other readers who may not be familiar with the issue. Here’s a New York Times article that discusses vermiculite.
In general, modern sprayed in foam insulation outgasses minimally. However there have been horror stories where people with chemical sensitivities have been bothered by the odors for some time. In spite of that, I still find it is the overall best insulation product, especially in situations like yours. However, if you’re concerned about it, I would have your spray-foam contractor take you to a couple of their recent jobs so you can smell the air and determine for yourself whether the odor levels are objectionable. If they are not willing to do so, take your business elsewhere. Many homeowners would be happy to share their experiences and open their homes to you before making such a large investment.
In addition to the attic floor, you might consider sealing the open cavities in your utility room where the vermiculite has been trickling in. I would hesitate to leave those areas open.
While I usually recommend closed cell spray foam for all this type of work, you may wish to investigate open cell foam. In my experience, open cell foam has less of an objectionable odor than closed cell, due to the water-based blowing agent. For this reason, they are also far less of a petro-chemical concern.
As for the insides of your walls, depending on their construction, you may be able to have them injected with cellulose insulation. This is fairly common these days, though it can be difficult to find a good insulator. If you’re any where around Chester or Lancaster Counties, PA, I can refer you to someone who just did a great job for a friend of mine. Their contact information is:
Pencroft Insulation, Peach Bottom, PA
They do foam and cellulose as well as insulation removal
Owner: Elmer Beiler, Jr.
Phone: 717-471-1785
Email: info@insulationbypencroft.com
Web: http://www.insulationbypencroft.com
A couple final notes:
If you have brick walls, usually you do NOT want to fill the cavities between the brick and the wall with insulation as the insulation will restrict the natural air flow which is intended to dry the brick. Most people don’t know that brick is naturally water permeable and needs about a 1″ air space behind it.
And finally, your utility room ceiling – I would leave that alone unless the utility room is open to the outside. Typically utility rooms are very warm during the winter due to the furnace/boiler and water heater. That heat can rise up to help heat your home. However, if you still have a furnace/boiler or water heater in there that requires the room be vented to the outside, and the room above it gets cold, you may wish to insulate the ceiling. But since you mentioned the vermiculite concern, my reply is as before – seal up those gaps where the vermiculite is coming down.
Hope that helps.
Hi Ted –
I’ve been reading your tips. We live in Randolph County in a home built in 1939. It’s a 1 1/2 or 2 story (depending on how you look at it) brick home…approximately 1900 square feet. We are spending a small fortune to heat and cool… $600 in August. I know insulation is not up to par and our windows are awful.
Can you recommend an insulation contractor in the area who knows what not to do (old house) as well as what will give us the opportunity to cut our energy cost?
BTW, I was about to contact a contractor regarding blowing insulation in the walls. Reading your post probably saved me a lot of heart ache.
Thanks
That vintage and construction is tough as you noted. I have had some people undergo major renovations by adding board foam to the inside walls then adding sheet rock over that. One of the few safe ways to insulate walls like that.
Roof/attic is much easier and will likely make a big difference in the summer. But you will probably want to air seal the attic floor before insulation is picked on top.
I’m going to recommend that you consider working with a local energy auditor before jumping into the actual insulation. A few hundred dollars spent analyzing your house can save you thousands by helping you prioritize the jobs. Unfortunately, I’ve known too many people who just went ahead with renovation without consulting someone and the house ended up worse after the work than before!
In addition, a good energy auditor /consultant should have contacts in the business and be able to tell you who is good and who should be avoided.
Hi Ted… first thank you for taking the time to read my concern.
I am in the middle of renovating my home and I had a couple questions regarding my insulation.
First, is there a difference between all the different colors of fiberglass insulation?
I ask because I’m going to replace some insulation in my kitchen and I was curious if there’s a recommendation. I have standard construction with 2×4 studs.
My second question is, after removing the drywall in the kitchen I noticed there was some plastic sheeting right behind the drywall covering the insulation. Is this a necessary step in reconstructing my kitchen? Do I need that plastic? My concern is that I encountered a lot of mold during the deconstruction of my kitchen and I am afraid that trapping air and moisture might cause the same problem again.
Sincerely yours,
Moon Hsu
The color is just a brand identification as far as I have seen. So I wouldn’t worry about that.
The plastic is a vapor barrier intended to stop moisture from moving. Unfortunately, as you see, it can have a negative effect in some situations by trapping moisture..
The mold you are finding is a concern. Can you tell where the moisture is coming from? Do you think that you have a leak on the outside that let rain water into the wall or do you think that the moisture may have come from inside and condensed in there? This is very important because if there is an active water leak, it could lead to structural damage to the wall.
Also, where do you live? If you have long, cold winters, the vapor barriers can be more important.
Happy to help you troubleshoot this issue.
Hi Ted,
To answer your question I live in Minneapolis MN. I brought a house 4 months ago not knowing there is a water leak problem. The house was build in 1969. The basement has Egress window and R10 Pink hard foam insulation throughout the basement. so I thought I will refinish it. That was when I realized behind the insulation there was mold plus this summer has been raining a lot and water started to leak thought the basement. I removed the plastic and insulation. I cleaned and resealed the basement . I then decided to move the kitchen cabinet from upstairs to downstairs only to discovered the whole kitchen was infested with mold. I assumed there is a water-leak from dishwasher in the past because it was on the cabinet, the wall, and the floor. I then removed the insulation from the kitchen which I had read your tip regarding black and brown spot on the insulation with air leak through from electrical outlet.
Like I was asking in the past, to re-insulate my kitchen on inside of exterior wall what grade and what types of insulation should I be using and should I put plastic sheeting back on?
Thank you for your help and love reading your tips…
Sincerely yours,
Moon Hsu
Hey Ted,
I’ve read most of your blog, thanks for taking the time to explain a lot of this stuff. As a first time homeowner (working on a house built in 1864) in Detroit, I’ve gone on all sorts of twists and turns playing the insulation game with different guys I’ve worked with on different sections of the house. When we did the block work for the foundation, we added vents to ‘let things breathe’, only for me to later read research indicating that it might be best to condition the crawl space and seal the vents off. Everyone, from the guy laying the block, to the carpenter, to the guy doing the hvac, had a different opinion on what was best to do in terms of insulation, and deviating from their plan is of course something that has to be done in a rather agile manner, so this blog has been a great resource in terms of being able to understand WHY things should be done a particular way, not just what or how.
So, that brings me to the issue at hand: the house has a 20×20 garage that I work out of during the cold winter months, and I’m looking to keep the temperature above freezing in there this year. We recently re-roofed the garage, and installed a continuous ridge vent as well as some sort of continuous intake along the bottom. Again, using the let it breathe mantra, for better or for worse.
Anyway, what I’m wondering is what your thoughts are regarding the best way to insulate the attic from this point forward. In case it matters, I should add that the roof is on 2×6 rafters 16″ on center at a 45 degree pitch. There is an attic in the garage on 2×10’s, which gives me very easy access to all of this. Anyway, here’s what I’m thinking:
1. Install 1″ tall x 1.5″ wide strips between rafters.
2. Rip sheets of foil-backed rigid insulation to fit between these rafters, attached to the strips, foil facing out toward the roof. This will have the effect, I’m hoping, of a baffle as well as a radiant-heat barrier?
3. Fill the remaining space between the rigid insulation and the 6″ rafter with fiberglass insulation. Probably the stuff they make for 2x4s.
4. Cover the entire face with 2″ rigid insulation. Would another application of foil-faced insulation would be beneficial here? Would it matter which direction it faced?
I know that spray foam probably has a use here, particularly right up against the foil-backed insulation, but I’m reluctant to use it unless it is just absolutely superior to any alternative, so that played a role in my decision making process. But really, I’m all ears. Thanks again for taking the time to do this!
I like the approach of steps 1-2. Giving the air channel to ventilate under the roof decking and providing a radiant barrier will really help to keep the attic much cooler in the summer and help reduce the chance of moisture damage to your roof. FWIW, moisture problems in garages tends to be minimal since the garage itself is usually pretty leaky so the garage humidity in the winter tends to be very low. Regardless, your approach is sound.
In step 3, you mention layering inside the foam with fiberglass. For a garage, I think this would be fine since the humidity will be low as mentioned above. I wouldn’t necessarily recommend this inside a house where there may be considerable moisture drive. In that case, the moisture could get into that space then condense on the colder surface of the rigid foam board below the roof. Just a caveat for those who might be considering such an approach in their house.
In step 4, adding the additional rigid insulation layer would be great for a couple of reasons:
First, putting the rigid foam across the rafters will greatly reduce thermal bridging, which will help keep out the the heat during the summer and minimize the chance of condensation on the cold rafters in the winter. Again, condensation will likely not be a concern, but your approach will virtually eliminate the problem.
Second, if you tape the seams with foil tape, you will be creating an almost completely moisture impermeable layer, greatly reducing the potential problems mentioned in step 3. I.e. this complete solution could be used in a home with high moisture.
Last thing – you want foil side down since you’re filling the cavity with fiberglass. In order for a radiant barrier to be effective, there needs to be at least a 1″ gap (1″ is approximate) between the foil and any other surface or the effectiveness of the radiant barrier diminishes.
If you go the route you’ve outlined, your attic should be very comfortable year round provided you’ve done a good job insulating the rest of the attic and garage. Remember the gable end walls too. You can apply the same techniques to fully insulate the space.
Our insulator recommends open cell foam on attic floor covered by blown cellulose. Does this make sense? I see that hybrid method usually uses closed cell + cellulose. Is this recommendation ok? Other option would be to use just blown in cellulose but they would still air seal individual cracks using open cell foam.
Open cell foam can work well for air sealing. I don’t see any reason to use foam and cellulose in this way. Just spray a thick layer of foam and be done with it. Cellulose is very messy and makes work in the attic miserable. I don’t know any reputable foam contractors who would recommend going that route. It sounds like they’re trying to cheap out on the job. You’re the one who has to live with the results. Pay a little more and do it right.
Hi Ted,
We are buying a commercial building, originally an old barn that has an unvented roof. The heating system is hung in the attic from the roof. We’ve been told to insulate the space around the heating system but should we do this if the space is unvented. There is a window at one end. We were thinking to fill the rafters with Roxul, leave the window open a crack and call it a day. What do you recommend?
This type of construction could have unintended consequences. If you add insulation to the floor of the attic, then the attic space and roof underside will be colder. Potentially, this could give rise to condensation problems. Opening one window could help but it could also make the problem worse as it could draw humidity from the main space below.
If the HVAC is up there, you’d be best off insulating right under the roof, turning the attic space into part of the heated space of the building. But care must be taken with this too. If you use a moisture permeable insulation, like fiber glass or roxul, even with a vapor barrier, there’s a very good chance that condensation could form on the roof sheathing. The safest would be closed cell spray foam. It’s much more expensive in the short run but in the long run it is likely to save your roof from rotting.