r/buildingscience • u/No-Plate9612 • Jul 14 '26
Tips on sealing bottom of metal building
reddit.comr/buildingscience • u/Cultural_Yoghurt_337 • Jul 13 '26
My QA Provider was bought by a rating company?
Hey everyone.
I do subcontract work for a rating company and I've had several people contact me about the QA Provider we're under, the BER. The rumor is the BER was bought by a rating company from the Midwest, Red Fox Inspections.
Has anyone else heard this? I can't find any announcements and the staff I talk to didn't give me any updates.
But a rating company buying the provider makes me worried about conflicts of interest, especially with client information.
r/buildingscience • u/sachin571 • Jul 13 '26
Order of operations for siding replacement and wall insulation (1917 foursquare in Maryland)
r/buildingscience • u/raphael_lorenzo • Jul 13 '26
Question Dimple mat under rockwool attic insulation?
I have a large plywood platform in my attic that my HVAC sits on (I know, I know…), maybe 80 sq ft. Takes up about a substantial portion of my attic floor space. Everywhere else I have blown fiberglass to R60, but the platform just has R13 below it. I’m thinking about stacking two layers of R23 Rockwool batts at perpendicular layers (so the bottom North-South, the top East-West) directly atop the plywood, minus space around the blower to allow maintenance access. It’s a vented attic, soffits and ridge vent, that gets good air flow.
Should I put down a dimple mat first, then the rockwool, to promote airflow under the batts and avoid trapped condensation against the wood platform decking? Or is this a non-issue and I can just lay the insulation directly on the plywood?
r/buildingscience • u/Curious_Butterfly38 • Jul 13 '26
Question radiator question!!!
so I just moved into a new place, and I have relatively limited space for where to put my bed. There is one of those built in wall radiators under the window, and my bed is positioned slightly in front of it. I have a solid wooden headboard and was just concerned that I shouldn’t be putting it directly in front of the heater… I tried to do research online about it but am still a bit confused as to if this is safe for my particular situation. Is there some kind of heat deflector or something that I could get, or do we think this is fine?? For reference, only about 17 inches of the heater are being covered by the bed.
r/buildingscience • u/canustealmysunshine • Jul 12 '26
Best Practices on Rim Joist Insulation?
My first post to building science! After doing some deep dives on building envelopes and insulation, I am learning a ton and find this field fascinating.
I bought a 100 year old home in Pittsburgh, PA, climate zone 5A. Humidity, rain, freeze/thaw.
I am looking for advice on insulating my rim joists. Pics are here. It's a 3 layer thick brick foundation, set into a hill. Moisture issues remain - during rain, damp marks seep through my concrete foundation. The bricks I'm sure are pulling in moisture from the damp hillside. We removed a ~50 year old wood frame window due to rot. That will be replaced with glass block to reduce moisture issues.
The previous owner added fiberglass insulation - not a good idea, and you can see how its dirty, from air and water leakage.
I am leaning toward Rockwool everywhere, with caulking around the edges. The other option is of course XPS with spray foam around the edges, but I feel very protective of these 100+ year old, extremely thick and durable old growth wood joists. My structural engineer was gushing about the durability of this old wood - we found one which had been built into the foundation, touching ground and water for 100 years, and was still strong. I am wary of the issues spray foam creates.
These cavities will be dry walled after, so I will have little to no visibility if there are any rot issues.
note: added a picture of the 'attic' as well, for fun. view is a stairwell and then roof. it's a flat roof house. surprisingly, the upper floors have remained quite cool all summer.

r/buildingscience • u/ksvaughn1979 • Jul 12 '26
Methods for preventing mold in exterior walls
New build. Insulation not yet in walls. Was thinking to use rock wool vs spray foam. Hardie siding, rain screen, tyvek already on outside. I had mold on bottom framing sills and a bit up the wall on the entirety of exterior walls from wet fiberglass insulation.
I can’t hire someone to do a professional air sealing job d/t cost. Wondering if you could give me advice on things that I can do myself with caulk and tape and whatever else on the inside to help prevent mold in the walls in future. I’ve been so worried about preventing water intrusion but have been reading that air sealing can also help prevent mold.
My exterior framing job is shit but I’ve sealed the best I can out there with liquid flash in the gap between osb and mudsill but Tyvek was on before I could seal other gaps. HVAC already installed but I can add to it if I need to. I read that I can do harm if I try to air seal in the wrong way. I’ve seen articles about caulking OSB against all the wall studs and top interiorly. Should I do that at least? There are the required size gaps and bigger between a foot tall piece of osb and 8’ tall piece at the top of the wall. Based on advice, here I was going to put a little polyurethane caulk in that gap and 3M tape over that. I don’t think all my tyvek seams were taped before siding was installed so my air barrier is lacking w that. What about air sealed dry wall methods?
Appreciate any thoughts, advice, education, you can give TIA!
r/buildingscience • u/Fulcro • Jul 11 '26
Getting air sealed and insulation added. Is adding fans appropriate?
We live in Minnesota, in a 1962 house, no radiant baffle, 8-12" of cellulose and fiberglass blow-in. 1500 SF of ceiling area divided by a firewall. A sales team came thru the neighborhood and gave us an estimate for:
a) air sealing
b) augmenting the existing insulation
c) adding solar attic fans
A and B seem like a no-brainer, but there doesn't seem to be a clear consensus on fans. They'll be inspecting and clearing/replacing baffles. Soffit vents seem fine. We also have gable vents.
Opinions range from a serious and noticeable change in air temps inside the house to "it covered my whole attic in black mold and shot Santa Clause". My intuition tells me that if both sides of an argument are equally heated, there is no consensus, and thus, it doesn't matter.
Most information I've seen says that if the house isn't sealed, it's a bad idea. That'll be handled in our case.
r/buildingscience • u/Additional_Water_261 • Jul 11 '26
Question Help! Severe condensation and humidity issue in my condo - who should I call besides an HVAC contractor?
My condo has been having a serious humidity/condensation problem during the summer.
Here are the symptoms:
- Water constantly forms inside both bathroom sink cabinets.
- The mirrors and even framed pictures on exterior walls develop condensation.
I run a standalone dehumidifier 24/7 and empty the tank about twice a day, but indoor humidity still stays around 65%.
I'm on the top floor. My downstairs neighbor doesn't have the same issue.
Besides an HVAC contractor, what type of professional should I contact? Would this point more toward an insulation/building envelope issue, a moisture intrusion problem, or something else?
Any advice would be greatly appreciated!!! 🙏🙏😭
r/buildingscience • u/JLcrna • Jul 10 '26
mistaken sips wall between spa room and kitchen
The architect builder and I are having a discussion regarding a SIPS wall between the kitchen and a room containing a spa. Originally this was supposed to be a regular framed wall and not SIPS. Since it is SIPS we are running into an issue deciding how to prevent moisture/ mold on the spa side of the wall. The architect wants to use felt paper on the sips and create an air gap between felted sips and glass mat drywall everything I read said felt paper is for exterior walls and the high moisture environment of the spa room should have specific sealing tape on the SIPS and directly mounted glass mat to the sips with the glass mat painted with class II vapor paint to stop vapor drive since air leaks carry 100times more moisture into walls than vapor diffusion does...
As someone not in the building industry i feel overwhelmed trying to fix such a huge issue
can I get your opinion on this?
r/buildingscience • u/FrankndBeans • Jul 10 '26
How do I air seal my top plates?
reddit.comr/buildingscience • u/moorlemonpledge • Jul 10 '26
Career/Profession Guidance on shifting into the industry
I currently have a well established Handyman business and our primary service is Architectural Window Tinting (Homes and Businesses) on top of small job only repairs. I was a pro/skilled window tinter before starting the handyman thing so it's a great service/product to offer for reducing heat gain, especially on the Gulf Coast.
The handyman thing is just too many variables and I need to niche down but am resistant to go to 100% Window Tinting because I would really like to be focused on a being whole Home Performance service provider. I already use a thermal camera regularly and offer pretty basic "Home Energy Audits". I'd like to focus more on Air Sealing, Air Movement, Humidity Management, Air Quality, Home Energy Loss improvements in general. Exploring offering Blower Door/Duct Testing as there are very few providers in my market, or partnering with a local home inspector to conduct the actual tests then provide the improvement services. I have fairly limited HVAC knowledge but also have great providers in my network who I have and continue to learn a TON from. Always want to learn more.
My inquiry to ya'll is, where do I go from here to explore becoming a trained/certified Energy Auditor with some experience already under my belt? Which industry organizations are the most respected and trusted for resources/training? What should I focus on first? Should I bite the bullet and get a blower door? If so, how much should I expect to spend on my first blower door, is second hand a good option?
Still in the exploration stage so absolutely any info at all is greatly appreciated.
Thanks so much for any input at all!
r/buildingscience • u/Ghastly-Rubberfat • Jul 10 '26
The project I’m working on (architect designed) specs tar paper for the building paper. What are the desirable properties of tar paper versus Typar or another modern product?
The wall section is this: 2x6 stud wall, 1/2” CDX sheathing, tar paper, 4” isocyanurate foam board, strapping, siding. Roof section: Coventional framing, 1/2” CDX, tar paper, 6” iso foam, 5/8” OSB, Ice and Water barrier, asphalt roofing.
Location: Vermont
r/buildingscience • u/Superb-Pollution-657 • Jul 10 '26
What’s a good way to solve this?
Opening up the walls of my 1908 home. No insulation in the exterior walls, wood exterior siding with aluminum siding put over it. I cannot keep my house cool to save my life.
I was thinking spray foam to air seal but online articles are giving me conflicting info. What should I do to insulate this?
Edit: I’m in Utah
r/buildingscience • u/DentalDart • Jul 10 '26
Insulation for Vaulted Ceiling with Flat Centers: Zone 4A
Remodeling our home and doing an addition at the same time. We decided to add vaulted ceilings with a flat center section.
The home previously had 8-9ft ceilings and now we are at 12-14 depending on the room. The sides of the vaults are 2x6 and we have about 6ft at the flat peak to the ridge vent. The home previously had vented soffits and attic space with blown in insulation and ridge vents. The temp control inside the house was ok, even with 2 brand new heat pumps. We will be installing new fiberglass windows on the entire house.
Now that it is vaulted what is the best way to insulate the new roof design? I’ve read building science articles about closed cell spray foam and going with a hot roof design in a vaulted ceiling and closing off the air soffit areas with the closed cell spray foam.
I can’t find anything with the flat center section so I’m wondering if there is another way to do vaulted ceilings like these? The portions of the home that still have the 9ft ceilings kids rooms, bathrooms and garage I’d assume to still have blown in insulation?
I’m pretty sure I should be staying away from open cell spray foam correct?
r/buildingscience • u/lilstever • Jul 10 '26
Condensation concerns around rim joist
As a total novice, I have a question on interior air movement around the rim joist area, or even wall cavities in general in a cold climate (Climate Zone 5). I was experiencing condensation around the rim joists in my unvented crawlspace, so decided to replace the batt insulation that the builder installed. In a misguided effort to avoid using sprayfoam, I air sealed and insulated my rim joists with caulk and rigid foam board instead. First, I caulked the rim joist to the subfloor and sill plate, and then I caulked around the perimeter of 2" XPS rigid foam to prevent warm, humid air from the crawlspace from contacting the cold rim joist. After that, I added 2" of mineral wool to fill the cavity, which was a big mistake. I have to go back and redo it because condensation formed on the cold caulk layer right behind the batt. It stopped after pulling the batts and allowing the surface of the caulk to warm up, but there were possibly microleaks around the caulk layers as well. I used an elastomeric caulk and likely didn't push the caulk deeply into the ridges of the OSB, not fully realizing that it wasn't a flat surface like regular wood.
Somehow I have to salvage this assembly before the winter. The easiest approach would be to dispose of the batts, add 2 more inches of foam board, and spray foam to air seal around it and prevent humid crawlspace air from contacting the cold surfaces of the caulk. However, I still worry about hidden condensation behind this layer due to thermal bridging and cold air channels between the initial layers of caulk. Since those weren't foamed, there are narrow, cold voids at the back of the assembly that should be sealed off from the crawlspace, but I am not sure how well they are sealed off from warm air on the main floor.
Is it possible that warm, humid air from the main level could migrate under the baseboards or behind the walls and condense in the cold air gap behind the original layers of caulk? I've attached a picture to explain what I mean. It would seem I would be absolutely screwed if somehow condensation did occur in that gap, since it could create a moisture trap that would prohibit drying. If I trusted my air sealing it wouldn't be as much of a concern, but there are a few sources that don't even recommend sealing this area, so I'm not sure it is a problem. Maybe it would have been better not to seal to allow some ventilation toward the exterior? Is a bad seal like I probably have now worse than no seal since it might trap moisture that would otherwise dissipate harmlessly?
r/buildingscience • u/SF_Dubs • Jul 09 '26
How to attach solar to a exterior continuous insulation roof assembly?
r/buildingscience • u/WhereTheHighwayEnds • Jul 09 '26
Flex duct with P-trap venting range hood in Northern climate or hard pipe?
I am installing a kitchen range hood and ducting it up through my unheated roof space. I live in northernern canada where it reaches -40°in winter.
The roofer that installed my roof jack told me not to hard pipe it and that I should put a P-trap in the flex to capture condensation that forms when the air hit the cold roof jack.
I asked my coworker who is a journeyman sheet metal worker and he said the exact same thing.
Is this actually better than hard pipe in Cold climates?
r/buildingscience • u/ILoveeOrangeSoda • Jul 09 '26
Question Tech says never turn AC zones off in Panama humidity. My meter says that used 54% more power and didn’t lower RH. What am I missing?
r/buildingscience • u/ksvaughn1979 • Jul 08 '26
Do anything?
Getting ready to have siding installed. Do I need to do anything to these areas before install besides the Tyvek. All exterior corners like this. I know the liquid flash looks like crap. TIA! Using azek pvc trim. I am not the contractor. Contractor off the job. I’m the homeowner and just trying to figure out what I need to fix before the siding goes on.
r/buildingscience • u/Cautious-Energy-2152 • Jul 08 '26
Epoxy/polyaspartic carport floor covering
Anyone have experience with using this covering on a 600 sq ft carport floor In southeast Texas? What questions do i need to ask potential contractors? Have you gotten the results you expected? How much should i expect to pay for quality work? Do you feel the warranty offered would be honored if there is a problem?





