Ask Ted!

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.



1,073 thoughts on “Ask Ted!

  1. Hi Ted, This sentence from this article describes my situation: “After deciding to tear off all the ceiling sheetrock, they found that almost all of the plywood roof sheathing was moldy,” except the mold in my case was discovered when I had the fiberglass insulation replaced in a small closet area. The mold on the sheathing was extensive, as far as the eye could see, and looks like it’s been going on for a while, presumably because of lack of adequate air flow though there has also been a leak around the chimney that goes through the closet area. I don’t know if all of the sheathing is in a similar state or if the ceiling dry wall is also moldy. What can be done in such a case?

    • I forgot to say I have cathedral ceilings throughout the house. The original owner said they “really packed the insulation in.” 😦

    • Hopefully, the chimney leak is responsible for the mold that you’re seeing in the closet area and the rest is clean. However, it would be wise to do inspections at other areas around the ceiling.
      Drywall is easy to cut and repair, though, of course, it requires re-painting, which is a pain.
      However, a professional can test for moisture in the drywall and roof sheathing with minimal disturbance. The moisture meters that I used to use included one that didn’t require any cutting – you just slid it along the drywall and it was able to report moisture levels. This is the first test that I’d have done. However, these moisture meters are fooled by metal so you really need to have a second type of meter that has pins that stick into the drywall and measure moisture directly. It’s still very low impact (no cutting or drilling, just a couple pin-pricks) so testing can be done without much visible damage to the ceiling.
      In order to measure the roof sheathing, which I’d recommend based on your assessment, you’d need to go on level beyond this and get someone with a moisture meter that has long probes. These require drilling a couple of small holes (1/4″) in the ceiling. The probes stick through those holes and reach up to the insulation and roof sheathing to measure moisture. It’s likely that the roof cavity is so deep that the probes won’t be able to reach, in which case you’ll actually have to cut out small sections of drywall.
      These types of tests will let you assess the extent of the moisture in your ceiling and plan your next steps.
      The first real question is: “if there’s moisture problems other than the chimney leak, where’s the moisture coming from?”
      Do you have recessed lights or other “holes” in the ceiling that would allow air/moisture to get into the ceiling? Without that, even with roofs packed with insulation, you usually won’t encounter moisture issues except in extreme climates. If you do have recessed lights cut into the ceilings, then those are almost certainly the culprits, so I’d test for moisture problems directly above the lights. It’s possible that there’s minor problems there (slight mold or darkening of the wood) that you wouldn’t have to worry about but replacing the recessed lights with air-tight, flush mount LED fixtures is highly recommended in order to reduce the risk of more extensive future damage.
      It can be hard to find a professional good at troubleshooting these types of issues. Almost no building contractors have the equipment so you need to rely on a specialist in moisture issues. You’d have to find out if they have the various types of moisture measuring equipment. If they have the types I’ve described, they’re likely serious. There’s three types I’d ask about: 1) “non-destructive” meter; 2) ‘pin-type’ moisture meter; and 3) long-probe moisture meter. These are illustrated at this website:

      I would strongly advise against trusting a general contractor for this work. That’s like asking your GP doctor to handle your lung cancer. You need a qualified specialist.

      • Thank you so much for this direction. If the sheathing is determined to be moldy and damaged throughout, what would be the course of action? TBD if the ceiling drywall is also moldy but if so, I’m wondering if ceilings and roof would all need replacement. A terrible thought! And a hypothetical question at this point.

      • Yes, worst case scenario is truly worst case – full re-roof, new insulation, new drywall. However, that’s only if they’re no longer structurally sound. Actually, worst, worst case scenario, the rafters have gotten rotten and are no longer structurally sound. But I’ve not experience that, so the worry of that is minimal. Rotten roof sheathing is fairly common, so I would see that as a definite possibility.
        If it’s just moldy but still structurally sound, typically people do NOT rip it out. You can paint over it and seal the mold in. The combination of that and the enclosed nature of the ceiling cavity locks the mold away where it’s not going to become airborne. As long as the moisture problem has been dealt with, the surface mold isn’t reason for concern.
        Disclaimer – if you have any sensitivities or concern about mold, definitely have an indoor air quality specialist test the air to ensure there isn’t an airborne mold problem. I certainly don’t want to be cavalier about mold sensitivities!

  2. Hey Ted, I’m hoping you can help me out. I live in Massachusetts and own a two family property that had a new roof put on last spring. Recently with the cold weather the attic has had some moisture issues that seem to be from condensation. The only area with a problem up there is a section of the attic that is directly above an open second floor porch. I added R32 insulation to the floor in that area above the porch but I didn’t add any on the gable wall next to it but I was told that would help.
    The roofer, as i see it needlessly put a ridge vent on the house when it has gable vents on both ends of the attic and no soffit venting whatsoever. I covered the gable vents for now but i feel if i blocked up the ridge vent and went back to the gable system it’s used since 1900 it would be ok. Do you agree and do you think insulating the gable walls will also help? The attic does need to be re-insulated but it’s only this one corner at this time that’s become an issue.
    If the ridge vent were to be blocked off what would be the best way to do so?
    I think the house has survived for so many years with the tables and the roofer just put a ridge vent up there not understanding about how an attic operates.
    Any advice is a huge help, thank you.

    • Hi Paul, thanks for writing.
      Let’s go back to basics for a moment. During the winter, the most likely source of moisture for condensation in the attic is from inside the house, escaping up into the attic. It then condenses on the nearest coldest surfaces. The only time you might get condensation otherwise is after a warm spell, when the attic is colder than the outside temperatures.
      I’m assuming that this is a “cold” attic, not an insulated section of the house since you mention venting.
      For a vented attic, insulating any area of the attic that is not directly adjacent to a heated section of the house (i.e. the attic floor above heated rooms) is unlikely to help anything. The main thing you want to do is figure out how the moisture is getting into the attic from the house.
      Is the area where you see condensation facing north? That is, is it a section that doesn’t get any direct sunlight? That’s usually where problems start since those are the coldest roofs.
      Besides the porch, what is near that area underneath? Any bathrooms nearby or other sources of moisture? Bath fans venting into the attic? Do you see any “holes” in the attic floor near the condensation that might lead into the walls of the house? Often the walls carry moisture from the basement or bathrooms, up into the attic.
      It is possible that the ridge vent without soffits caused the problem. When you have mismatched venting, the air going out the ridge has to be replaced from somewhere, so it can “suck” air/moisture from inside the house into the attic. With balanced venting (i.e. equal air coming in and leaving, there is no negative pressure (i.e. sucking) in the attic, so air from the house is less likely to enter. That’s a reason attic fans are “frowned upon” by the building science crowd – they create a strong negative pressure in the attic that can suck a lot of heated/cooled air from the house up into the attic, actually raising you utility bills!
      So step 1 is to look for any source of moisture from the house up into the attic.

  3. I have a sick house which is making me extremely ill. I’m not sure if it’s the attic or basement; probably both. A septic tank (no longer in use is near basement, when it rains does this fill and cause gas to enter the home, (over 100 years old). I’m sure the walls have old rotten insulation, probably just newspaper and the attic has had critters of all kinds through over a century of use. I’m a woman, 74 yrs and my husband can’t do much of the required labor. We are in lower Michigan near Ohio. Winters are bitter and lately we’ve had more than normal rain and its very damp. Summer’s can get to 85-90. This sick syndrome is not continual. Happens usually in the spring. Rest of the year it is fine. Does this problems ring any bells? I’m at a loss at what to do or where to start. I’m in a motel as it is so severe I cannot stay in my own home. Thank you.

    • I think my best advice at this point would be to look for an “indoor air quality” expert who can measure the air and assess what pollutants are in your home. That will allow you to focus your time/money on the areas which are most serious.
      I wish I could give you more advice, but what you describe sounds serious and is in need of an on-site inspection.

  4. Hi Ted,

    I really enjoy reading your blog and have a question(s) for you.

    We just had a house built a few months ago and we keep getting dust from the outside, inside our house everywhere. The down stairs is worse than the upstairs, as we have 2 separate heat pump systems. The area surrounding our home was excavated and we’ve had all that dirt mud/red clay surrounding our house, making the environment dusty as it was, but the house is 100% sealed, or we think it is. No open doors, windows, etc and dust is everywhere. The HVAC contractor never put a filter in the downstairs system’s air intake, so the system was running for a good month before we even noticed it, sucking in dust. We called the HVAC company and they told us that they put in a filter and that someone must have removed it. I guess we had a visit from “Casper The Friendly Ghost”, as no one removed anything. Their solution was to charge me $1,100 to come out and clean the duct system, which was complete garbage. I called 2 other HVAC companies and told them the situation and they both told me that they doubt a brand new HVAC system would have collected that much dust in a month, to warrant the duct system to be cleaned. We had on of them come out and they cleaned the coils and look everything over, as well as check the duct system, and they said that it did not appear that the duct system need to be cleaned. They said that it was probably from the dry dirt surrounding the house. That still didn’t answer my question of how it was getting into the house if everything has been properly sealed. We have 2 dogs that track in mud and dirt, and we also get it on our shoes from time to time, but not enough to cover the surface of everything with dust constantly. You can clean the whole house and within a day, it’s completely dusty again. The HVAC grills and filters get very dirty, very quickly. We recently had the yard seeded and sown and now have grass in most parts with some straw on the other parts that have not fully came in all the way yet. I figured this might fix our dust issue, but it has not. We are still getting in a bunch of dust. We’ve installed Honey Well Return Grille Air Filters that are 2″ thick and have a MERV rating of 11 to see if it would help, and it seems as if it has not. I’m not sure where to go from here and could really use some advise. We live in East TN, near Knoxville and would like to know if there are any professionals in the area that could come check out our situation. Any help, ideas, advice, input, etc would be greatly appreciated.

    Thank you,


    • Hey Ray, thanks for writing,
      You’re smart to be persisting with the HVAC people. I can’t believe the one company wanted to charge you a grand to fix their problem! Hopefully, you’ll never have to deal with them again – sounds like a con-artist 😦
      You hit the nail on the head when you wrote: “That still didn’t answer my question of how it was getting into the house if everything has been properly sealed. ” – Exactly!
      So the question is, where the heck is the dust coming in from?
      You’ve done great troubleshooting, especially with the return air filter. What that tells me is that the system is sucking air in from somewhere between the return air grill and the air handler – i.e. the return duct has an opening to somewhere extremely dusty.

      Here’s a possibility – some builders use wall and/or floor cavities as ducts. It’s extremely shoddy practice because it can lead to really dusty homes since it’s not a properly sealed system. It’s also inefficient. You can ask the installer if they did this. Of course, they might just lie and say “of course not”, in which case you would be within your rights to ask for that in writing. Then, you can check it out yourself by pulling off the return air grills and shining a light down the walls to see if there’s actually ducts in there. I usually find this situation on wall mounted returns but many floor returns do this too. You might have to use a mirror to peer down the wall cavity (or floor cavity) and you can also feel it with you hand by sticking your arm in there. Just be extremely careful of sharp edges on ducts which can be like razors. I know from experience…

      Unfortunately, if they did do the returns this way, the practical solution is to cut out the sheetrock and install real, sealed ducts wherever it’s missing. Obviously, this is undesirable, but frankly, it’s a heck of a lot better than dealing with an extremely dirty house for the rest of your ownership. Plus, it’s not really healthy. Mice love these areas and are prone to leaving all sorts of nasty things in there…

      Good luck. Please let me know what you find.

      • Thanks for your reply Ted. I believe that there are actual ducts in these areas of the house, but I’m going to contact a company called Prudent Energy Systems in Knoxville and see if I can get the to come out and do a dust blaster test on our systems, to see if we have any leaks, and to check for any other problems in general. I’m currently overseas and my wife really isn’t sure what she’s looking at when it comes to these type of things. I’ll keep you posted.

        Thanks again,


      • Great! A duct blaster test is exactly the right approach to take. The system has got to be sucking in that dust from somewhere.
        If they have a thermal camera, those can be extremely handy in quickly finding big leaks in the supply ductwork as you’ll get hot spots showing up. Harder to find on the return side.
        The supply ducts can suck in dust, even though that’s counter-intuitive. So the search will have to be thorough. But the duct blaster should give you good info.
        If they don’t find leaks in the ducts, I’ll be scratching my head!

    • it depends on how bad the roof is. obviously if it’s so bad that it’s leaking, then it will adversely affect your home’s Energy Efficiency. on the other hand if the roof is still basically sound then the heat loss will almost entirely the due to how well are sealed and insulated the attic space is.

  5. Ted,
    Not sure if this is your area of expertise, but you haven’t let me down yet, so I thought I’d give it a shot. Just had an old concrete porch removed from the front of my house and it exposed some previously covered foundation. The crawlspace is entirely encapsulated with rigid foam and air-sealed, so the only exposed foundation is on the outside side. The basement will eventually get the same treatment (rigid foam on the walls and air-sealed). What is your opinion on painting exposed foundations? The previous owners had already painted mine. Foundations are mostly in the ground so they’re always damp and absorbing moisture. I had always thought that the portion that is above ground is the only opportunity for any moisture in the foundation to escape. If someone were to paint it would they be locking it in and doing potential damage to the concrete? Or potentially forcing that moisture up through the foundation plate and rim joist and maybe even into the wall assembly?
    Thanks in advance!!

    • well, that is a different question for me.
      you’re right, it is out of my realm of expertise, but maybe we can think this one through.
      I do know that’s often exteriors of foundations are coated with a waterproofing sealant, so painting it should be little different as far as the effect on moisture. since it is sitting in moist dirt, just like a normal foundation it will always be wet. The thing is now that it’s exposed it will be potentially subject to freeze thaw cycles which could lead to cracking. but I would imagine this would be the case regardless of whether it was water sealed or not.
      so I guess my real answer is “I don’t know” 🙂

  6. I recently purchased a 1-1/2 story Cape-style house that was built in 1959 and is in need of some updates. A previous owner updated the house in the mid-80’s and I’m currently in the process of undoing their work.

    When removing the interior wall coverings, I discovered there is no insulation in the exterior walls and I’m wondering if I should add insulation or leave well enough alone and button everything back up with new drywall.

    Prior to the original siding installation, the exterior of the house was horizontally “wrapped” in 6″-10″ boards and some of them have 1/4″-1/2″ gaps that have allowed pests to penetrate through the years. At a minimum, I would like to make the interior of the home less accessible to creepy crawlers.

    I have a game plan, but I do not want to DIY myself into a situation that will require a professional to fix down the road. I’m seeking advice before I make an expensive mistake.

    Is following method logical for this scenario?:

    1 – Seal the 1/4″-1/2″ gaps with a closed cell canned foam such as Great Stuff.
    2 – Install an encapsulated fiberglass insulation without a vapor retarder such as Johns Manville ComfortTherm R13.
    3 – Install a 4-6 mil barrier across the face of the studs.
    4 – Install and finish new drywall.

    Note: The house is located in a woody area in central West Virginia. The summers can be humid and the winters can be frigid. The house is located on the border of climate zones 4A and 5A. Climate zone 4A is the official classification, but the next county over is 5A.

    • If the walls are standard construction, framed out with drywall on the inside and the boards you mention working as exterior sheathing, then that looks like a sound approach. If you want it tighter and even better insulated, since it sounds like you’re ripping out the drywall anyway, you might consider adding a layer of faced polyiso sheet foam, maybe 1/2″ thick, to the interior studs, then put up the drywall. You wouldn’t need the interior barrier then as the polyiso would act as a moisture barrier,. I’m thinking 1/2″ because that might be thin enough that you wouldn’t have to extend widow jambs much. However, it may turn out to be too much of a hassle if it changes the way they’re framed out. In which case, you could go as you mention.

      • Ted, I greatly appreciate your insight.

        Over the last few days, I’ve read some nightmare scenarios regarding insulating the walls of an older home and effectively creating a wet environment.

        At some point, probably when the home was updated in the mid-80’s, a previous owner installed vinyl siding. I’ve not yet determined if all the original wood siding is present under the vinyl, but a rear full-width porch was converted to finished space and wood paneling was installed over the original wood siding in that area. That particular area is now an interior wall, so my insulation of exterior walls will not effect this area.

        Given the above information, would the earlier method I mentioned still apply if I discover original wood siding remains under the vinyl?

        What if the wood siding was removed and the house was wrapped prior to the vinyl installation (unlikely, I know)? I assume my plans will need to change if this is the scenario, but I’m not sure of the extent of the change. Would I simply omit the 4-6mil barrier across the face of the studs if an exterior barrier was installed?

        …maybe I’m in over my head.

        I apologize for supplying so many scenarios.

        Guidance would be most appreciated!


      • The vinyl siding itself should cause any problems. It’s not air-tight so moisture should be able to drain out. I’d probably want a Tyvek or other barrier like that between the sheathing and the siding, but otherwise, that should be no problem.
        The interior moisture barrier should be fine also. These days, in most places, building scientists don’t see a need for this for the reasons you mention. This would allow any moisture that might get into the walls to dry to either the inside or outside, so you could save yourself the effort. Painted sheetrock is actually minimally moisture permeable. So just do your best to seal around outlets and other holes you make in the wall. Those types of things let hundreds of times more water into the wall than can pass through the sheetrock.

      • Ted,

        I’ve given this considerable thought and I’m positive new siding will be part of the plan a couple years out. I’m leaning heavily toward a Hardie product.

        For now, I think I’m going to modify the wall insulation plan (from the inside out) as follows:

        1 – Finished sheetrock
        2 – Omit the 4-5mil barrier
        3 – Encapsulated fiberglass without vapor retarder between the studs
        4 – Canned closed-cell spray foam in the cracks between the plank sheathing.

        When the time comes to install the new siding, I will specify everything should be removed down to the plank sheathing and the house should be wrapped prior to the installation of the Hardie product.

        Thanks again for your insight. This place is a wealth of information.

        Kind regards,

      • We did a Hardie siding for a while on our house. Durable and good looking.
        Good luck with your project! And thank you for your feedback. All the best.

  7. Hi Ted, I have two houses. One was built in 1967 and the other one 1972. Both have a gable roof, brick veneer with weep holes and are on a slab. #1 has gable end vents, soffit vents and 2 whirlybirds near the roof peak. #2 has soffit vents and a ridge vent but no gable vents. Both also have gas furnaces that draw combustion air from the attic. Both also have apx 12″ of blown in insulation in the attics.
    A foam contractor wants to completely seal the gable ends and roof decking with closed cell foam. I asked about the source for combustion air and he had a blank look then said no one ever asked that question before. I assume that a properly sized duct would need to be installed. I am also concerned that the wall space will not be vented any longer.
    Both houses are located 60 miles northwest of Houston,Texas. Thanks Rick

    • That doesn’t give you a lot of confidence in him, I’m sure! You definitely need combustion air but adding a vent defeats the purpose of the insulation. If the furnace is old, you might consider replacing it with a direct vent unit that draws combustion air through a duct to the outside.
      A sealed attic of this type is usually ok. Ventilation is usually used for either cooling or moisture control. The foam, if properly done,solves both problems.

      • Thanks Ted, that makes me feel more comfortable about the foam on the roof decking. I was hoping that I could retrofit the old furnace with a dampened duct if it was properly sized for the furnace and distance to the gable end. House #1 has a 29 year old Trane so it will be replaced next spring. I will be sure to get a ducted heater for that house. Rick

      • you can rig something up. Sometimes they do this for furnaces in homes. They run an appropriate sized duct to allow fresh air in. Then they put the outlet, facing down, into a container, like a trash can. This allows cool air to pool without just flowing into the living space. It’s supposed to be quite effective.

      • Thanks again from the quick response! I have searched all over for information and your site is top notch. I am learning a lot and will keep on reading.
        I will get with someone to size the duct for the furnace. House #2 has a fairly new system. A/C is the biggest deal in our area, I think I used my furnace about 2 weeks last winter. Thanks again, Rick.

  8. Hi Ted, Thank you for your article about mold. We just received a mold report on a house we are selling… would you be willing to look at it and let me know if it seems normal. Our relator said she has never seen one, but it looks very discouraging and extremely high levels. (?) Appreciate your time.

    • hi there, thanks for asking. I’m afraid I can’t do this type of work and your best bet is to stick with your mold specialist. you might be able to find a second company around there perhaps look for a company that specializes in indoor air quality rather than just mold in order to get a second opinion. this is especially important when buying and selling homes because mold has become such a big legal nightmare.
      just be wary of extreme reports from companies that do mold remediation because they charged thousands of dollars and operate on scare tactics. that’s why I like to use a company that doesn’t do the actual remediation work. since they have no vested interest in selling Youth Services they’re more likely to give you an honest answer.

  9. Ted, first off thank you for the post on l.e.d. inserts, I will opt for this solution.

    Are gaskets needed? None came with the Phillips airtight inserts I purchased. If so, I assume a window seal would do the trick?

    New question – the home energy audit also recommended more attic insulation. We are currently at R30 and would like to get to R50+.

    We currently have batting topped off with cellulose. Do you recommend more cellulose, or is it ok to add fiberglass on top of the existing insulation?

    Thank you again!

    • It’s definitely best to get circular cutout gaskets, though many are really cheap foam and don’t do much. What you could do that would provide an excellent seal, would be to use that gasket material that’s like clay rope. I’d take a couple strands, roll it together into one larger strand and make yourself a gasket. Then compress the LED insert to the ceiling. I’ve not done this myself since I had already sealed my fixtures from above, but in your situation, I think that could work quite well.
      As for insulation – blown in cellulose is a double edge sword. It’s great because it goes in quick, is pretty inexpensive, and fills in gaps. Batt insulation is much more labor intensive and prone to installation errors which can leave gaps.
      The flip side is that blown in insulation is not good if you need to use the attic for other things because it hides everything then clings to your pants, making a big mess when you come down from the attic. But if you never access the attic, it’s a great way to go.

  10. Ted, we recently had a home energy audit and found that we need to seal some recessed lights to prevent air flow into the attic.

    We have a contractor quote to seal from the top down, i.e. using a fireproof box installed from the attic. Option 2 is more d.i.y., to replace the recessed lights with an l.e.d. insert and gasket.

    I would prefer the l.e.d. insert option given it is much cheaper and prevents the contractor from crawling around in a tight space.

    Are there any pros or cons I should keep in mind for both options? Is the l.e.d. insert option going to be as air tight as the fireproof box?

    • Adam, thanks for asking – that’s a great question, I should write a feature article about this because it affects so many homes!

      I’ll start by saying that I have upgrades all of the recessed lights in my home with LED retrofits. This has numerous benefits over attic sealing. Prior to good LED retrofits being available, I had constructed airtight/fireproof boxes installed from the attic, so I can comment on both from first-hand experience.

      The retrofits were easy to do, taking maybe 10 minutes each, at most. These days, high quality retrofits are inexpensive, typically less than $30.

      – Totally air-tight when installed with a good gasket
      – Energy efficient – depending on your electric cost, the light will pay for itself, especially if it’s in a high-use location, like the kitchen. Usually less than a year.
      – Energy efficient part 2 – you can insulate the attic properly above the fixtures. LEDs generate much less heat than incandescents. Plus, you won’t lose the heat from air escaping through the housing.
      – Long lasting – quality LEDs are rated to last about 2-4 years running continuously. Compare this with an incandescent which has a life only one-tenth as long. This is much more convenient (less time on the ladder is safer too!). For most uses, that means you’ll never have to replace a bulb.
      – The light quality of “good” LEDs is very natural if you buy high CRI (color rendering index) fixtures. This is very personal, so compare the light from different fixtures to find one you really like. I brought home several, installed them and then my wife and I could see how they looked in our own homes which is much different than the display case in the store. You can usually return the ones you don’t like, so it’s worth trying a few.
      – The retrofit itself is quite simple usually. Most wire into your existing fixture using a screw in connector that replaces the existing bulb.

      Challenges with retrofitting from the attic:
      – Working in attics is not fun. It’s hot, dusty and access is often difficult. This makes contractors less likely to do a good job because they’ll be anxious to work quickly and get out of there.
      – It can be difficult to mount the air-tight enclosure in the attic given the construction of a typical recessed light fixture. This often leads to compromises that leave gaps, defeating the purpose of an air-tight enclosure.
      – Incandescent lights generate a lot of heat. Some older fixtures aren’t rated for enclosure. Usually this isn’t a problem however.
      – Covering the fixture with a housing can make insulation challenging. Most contractors are afraid of insulating around fixtures, leading to compromised insulation.

      Other considerations:
      – Some are dimmable – so make sure to buy the right type if you need them to dim.
      – The convenience factor of not having to replace bulbs in high ceilings is worth a lot.
      – Make sure the chosen fixture is the right size (4″, 5″ or 6″) for your retrofit. There are also different mounting styles that can affect compatibility.
      – Avoid off brands or those without a good warranty. The only trouble I’ve had with LED bulbs/retrofits are with cheap “knock-off” type. My favorites have been manufactured by CREE, which were the pioneers in LED lighting. Phillips also makes quality products.


  11. Hi Ted,
    It’s July in the Laurel Mountains in western PA. It’s been unseasonably warm and humid, high 80’s and up. My kitchen/dining room cathedral ceiling is a combination of tongue and groove and sheetrock. We have central air conditioning, most of the time we don’t need to use it. When the temperature is the highest around noon and the air has been on, I’ve noticed condensation and dripping from the area where the sheetrock joins the wood. Our roof is closed – no ridge or soffit vents, air conditioning vents are on the floor. From construction pictures that came with the house, it looks like the insulation is solid. The leak seems to be from the ridge and dripping down the slope. We had ceiling fan put in this past winter, it hangs from the boxed ridge. We’ve had a roofer check and there are no noticeable issues with the roof. After reading the comments above, I’m wondering if we need to open the boxed ridge and check if the electricians removed the solid insulation in the area of the fan? Other suggestions?
    Thanks, Deb

    • It is strange that the issue occurs under those circumstances. Normally, mid-day, the roof would be hot, leading to the least likely conditions for condensation.
      The location, where the sheetrock joins the wood is expected, since that seam is where the water could drip out. It’s also where the moisture from inside the house could rise up into the cavity.
      One possibility is that the wooden beam is cool enough (because of the air conditioning) that when the hot, humid air from outdoors comes in contact with it, it condenses, then drips down the beam and into your house.
      Did the dripping only start after the electrician added the fan?

      Another possibility – do you open the house up at night to get fresh air? Nighttime air is cooler and often saturated with moisture. That moisture could float up to the peak and condense on the cooler wood. I couldnt’ say for sure that is the cause, but it’s a possibility.
      If you do open the house up, I would discourage doing so on anything but low-humidity days. I’m always tempted to get fresh air too but usually regret it because of the amount of moisture that this lets in the house. Then I spend all day running the AC to remove the moisture.

      If the dripping continues in spite of being diligent to prevent excess moisture from entering the house, I would have someone carefully remove the ceiling along the wood beam so that the inside of the ceiling cavity can be inspected. If the wetting has occurred for a long time, it could lead to wood rot. You’d want to examine this and see exactly what is happening in there. Then formulate a strategy for “fixing” the problem. Without knowing the cause, I wouldn’t try to fix it by speculating about causes. That can lead to more problems and cost you $$$ and time.

      • It only occurs when we have the air conditioner running AND only during the hottest part of the day. We’ve only noticed it since the ceiling fan was installed. Thanks for your suggestions, I’ll have a contractor look at it.

      • That is truly odd! Based on your description, this is a longshot, but is there any chance that there’s an AC duct running up there? Often cold ductwork will lead to condensation. Highly unlikely given what you’ve described, but I wanted to rule out all known possibilities.

  12. Hi Ted,
    I recently purchased a home and have undertaken some substantial renovations. My home has a metal roof with a low pitch. It has soffits around the perimeter but no ridge or upper vents in the attic or anywhere else on the roofs. There has been a history of ice damming and there were some leaks which I have fixed.
    I am now thinking to spray foam insulate the attic area, but want to know if I should seal the soffits? The ice dams occurred at the lower portion of the eaves in a seam between 2 sections of 2 different roofs with ceiling heights being significantly different. One vaulted and one a more traditional height.
    If I close cell insulate the attic, but keep the same batts insulation in the other areas, will the other areas require vents to be installed? And do the soffits in the attic need to be sealed?
    I’m sorry if this is a little confusing- I have been researching a lot of different information and have also received a couple of different opinions.
    I’m thinking a combination of spray foam and venting may be required.
    Clarity and any help is greatly appreciated.

    • The ice dam issue is typically going to be due to heat leakage from the house around the perimeter. Due to the usually poor accessibility where the roof meets the wall, this area is often hard to seal. With proper blocking and vent chutes, they could spray in foam while protecting the soffit vents from being covered and allowing air to flow up the soffit and under the roof.
      For example, here’s a video showing how you could do this:

      Granted, since you’ll have the ceiling/attic floor in place, it won’t be this easy, but you get the concept. Once the baffles are in place, the foam will seal the air leaks and provide excellent R-value. If you choose, you could then use loose fill or batts elsewhere. But I’d recommend at least foaming a thin layer over the rest of the attic floor (i.e. ceiling of room below) to seal all air leaks, then add less expensive insulation elsewhere. But use a thick layer of foam out near the soffits, against the baffle, to avoid ice dams.

      Again, with the low pitch, access will be a bugger. But it’s worth a try.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s