sealing air leaks along baseboard
This weekend i noticed that cold air was coming up from the baseboards, underneath and at the corners. My question is how to i stop that? do i seal it from the outside? or is it a problem in the wall itself? I foamed the outlets because they were leaking but not sure how to seal along the baseboards. there is carpet there so i dont really know how to seal that without major surgery. the outside access is much easier, just vinal siding… this is a 3 year old house on a slab. house is not wrapped, just FG in the walls…
thanks in advance for all the help…
Frank
We were the winners, cause we didnt know we could fail….
Waylon…
Replies
The short answer is that you will likely never stop it without major surgery.
That air is being drawn in by the stack effect of the house. Warm air is going out the top of your house somewhere (like at electrical boxes in your ceiling and other penetrataions) and the make up is being drawn in. You are feeling it at the baseboards, but it's origin is inside the wall. Small cracks in sheathing and other openings into the a stud cavity produce airflow into the wall cavity (where you probably have fiberglass which does nothing for airflow), then the air finds an exit on the other side of the wall cavity which sounds like it's where the drywall meets the bottom plate. Then it comes out from around the baseboard. My house leaks like this too. This is why I'm opening it all up and putting spray foam insulation in.
MERC.
what about blown cellulose into the wall cavity? it woulnt be too much trouble to pop off a few pieces of siding and pull out the FG and blow in cellulose from the top down. I used that on the attic and it seems to have greatly helped the second floor greatly, but didnt do nuthin for the first floor...
i ran across someone here saying that roofing felt makes a good and cheaper alternative to house wrap... would this help?
thanks again
Frank
We were the winners, cause we didnt know we could fail....
Waylon...
Housewrap is overrated crap. Tarpaper would do something, but I don't think it will stop the stack effect. It will probably shut down some wind blown leaks, but not air that is being drawn in pressure differentials.
Cellulose would help a lot. That stuff finds every little crack and seals it up. I had a house in MA with cellulose and it had settled so the top 4-12" of each cavity was empty. I'm sure that wasn't good for my heating bill, but neither were the metal casement windows.
How old is the house? I have a tough air sealing problem in my current (NC) house because the subfloor is 1x6 plank flooring, run diagonally. so every few inches, all the way around the perimeter of the house, I hav a 1/2" gap between the boards. the subfloor is under the bottom plate so you take off a piece of siding and there are all the gaps going into the house. Nice. As I tear the house apart, I've been sealing them up best I can (with cans of foam). I mention this because you are feeling the air coming around your baseboard. You can also get air leakage under the bottom plate of a wall, even if the subfloor is solid sheet material. The wall plates just don't seal down that tightly. In a really tight house, those joints should be caulked or the wall built on a gasket.
MERC.
"what about blown cellulose into the wall cavity? it woulnt be too much trouble to pop off a few pieces of siding and pull out the FG and blow in cellulose from the top down. I used that on the attic and it seems to have greatly helped the second floor greatly, but didnt do nuthin for the first floor..."
Did you say 3 years old? Tragic.
If you are going to go so far as to remove the sheathing, you can seal the leak with caulk/foam or blocking. While cells will plug small leaks to some extent, it is best to airseal big known leaks before insulating.
Another option to consider might be removing the baseboard for access.
As was said, the cold air will not come in at the bottom unless warm air is escaping out the top. The cost/benefit ratio is much better when you seal the attic plane. Tearing into the wall may not be the best place to start with your weatherization. Consider a blower door test.
Edited 1/24/2005 2:29 pm ET by csnow
tragic is not the word i was thinking of...
if this house was back in Wyo there is no way i could keep it warm. I would say if its zero out, in Atlanta, i would not be able to get the thermostat past 72, and that would be running constantly.i went into the attic and foamed all the places i thought air could leak past, lights , attic door, ect... and layed about 2 feet of cellulose on everthing... which made a huge difference upstairs, the bedrooms are all upstairs. I also noticed when i touch the walls to the garage they are much colder then the other walls, not sure how to insulate them, without tearing out drywall somewhere.thought about doing the fomofoam in the walls , but its just too pricey for me to realistically get that money back. the cells i can do for much lesss, just a lot of my own work..I appriciate your ideas, thanks...FrankWe were the winners, cause we didnt know we could fail....
Waylon...
Tear off that vinyl and wrap your house with felt. You can probably do a better job with felt than Tyvek or the like.
Where the air is blowing the rain will too.
Joe H
yes i was thinking of that come spring... kinda chilly outside now to do too much about it...funny though the second floor dosent seem to have this prob... some airflow in the outside walls, but not nearly what the first floor has.
thanks Frank...We were the winners, cause we didnt know we could fail....
Waylon...