Mad air leaks
Why are air leaks so hard to seal? When sealing with caulk I get air bubbles and when I smooth the bubble out another air bubble appears. Same thing when using tape , a corner will lift up or one end will shoot straight up and bubbles with joint compound as well The leaks just seem to move to different locations . The closet next to the supply return vent that’s inside a closet cavity inside the house , always feel cold and the ceiling feels drafty. Not sure what I can do to help the closet . The supply return vent is lined with duct board and I tried sealing the big box thing in attic with mastic. . But it’s not just in that area that air leaks give me trouble . It’s thru the whole house . It’s like they are angry , I call them mad air leaks cuz they don’t let me win. What could be causing this ? It happens whether the hvac is on or off. .
climate 2 , slab foundation , brick house , poor condition , chimney ( I don’t use ) .. 3 exhaust fans , dryer vent which I haven’t used in a year or so . The stack effect is real in this house .
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Replies
It might help to pressurize your house with a blower door kit and chase leaks with smoke.
What types of caulking/ sealant and tapes are you using?
Depending on budget, this could be an option:
https://aeroseal.com/aerobarrier-how/
No Locations near me.
Your other post said you were in the Houston area.
TNS Solutions in Spring serves Houston for air sealing.
I will look them up. Thank you for that info!
Surfaces need to be clean, dry, and at a temperature within the air-sealing product's specifications. Acrylic tapes only stick properly under pressure; depending on the product it could be hand pressure, a roller or squeegee. It will stick initially without pressure but imagine that the adhesive is little balls filled with goo that need to be released. Expensive tapes tend to work better than cheap tapes. Low-VOC, European-supplied tapes are generally very high quality. 3M 8067 is also an excellent tape but NOT low-VOC and will give you a headache if you use too much of it indoors without ventilation.
Metal surfaces virtually always have manufacturing oil on them--mineral oil--and may need to be cleaned with vinegar before applying tape or sealants. Though I've never had a problem with duct mastic sticking ok without an initial wipe-down. Foil duct tape also works well. The product sold as "Duct Tape" is terrible for sealing ducts.
Bubbles in joint compound can be from mixing too aggressively, incorporating air, or from application over a damp surface, or from contamination such as oil on the substrate.
There is likely a 2" gap around your chimney that needs to be sealed with sheet metal and high-temperature caulking. You shouldn't fill the gap with insulation because the chimney heat needs to be able to dissipate.
I have all sorts of tapes and I have expensive tapes as well and I think the humidity plays a roll. I have tapes from you name it 3m , and even go to the local hvac supplier to get tape from them and they perform well but like last night I have trying to seal the bath exhaust vent from inside the house . The bottom fan opening. I was trying to add tape right where the metal meets the drywall and all four corners and I guess the cold draft wouldn’t let the tape stick . That’s why I’m trying to work on air leaks to help with moisture in air . I got new pex pipes and plumbing checked no leaks .
I do think it has something to do with air pressure imbalances and I do think a blower door test is what I need. I just need to find a reputable company which seems hard to find in Houston .
This Aeroseal company serves Houston: https://aeroseal.com/texas-3/
For testing, you want a BPI-certified professional. I found four in the Houston area: https://locate.bpi.org/?type=1&search=1&certs=&lo_name=&lo_zip=77011&lo_radius=50&lo_state=&lo_results=all
🙏 thank you. This is very helpful