Ridged foam

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livefreeordie

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Nov 21, 2010
207
Rochester, NH
Any advice on how to install ridged foam on my basement walls? (interior) Will it help keep the basement warmer or is it a waste of time and money

Thanks
 
This is an area I'm looking into also. What type of board are you putting up, and what thickness? Do you plan to cover it after it's installed? Do you plan on putting nailer boards up before you finish it? Are your walls solid formed concrete, hollow CMU, or filled CMU walls? I'm finding out all types of information based on my walls- half filled CMU, half formed concrete. Yep, my house is a little screwy. I'm also looking at injected Icenene(?) after the interior walls are blocked and built.
 
It should keep the basement warmer. Are you just wanting to insulate the wall or are you planning to finish the basement? If your not planning on finishing it you could probably glue board onto the walls.
If your woodstove is in the basement it will increase the effiency of the stove I think. Unfinished basements are particularly bad locations for wood stoves because too much of the heat is absorbed by the walls and lost to the outside. So if you insulate the walls you may burn less wood and have a warmer basement.
 
+1 on the articles from Building Science that Semi pointed out....Lots of excellent articles on all the do's/dont's regarding insulation.
For my basement reno I'm going with 1" rigid foam on the walls....just using adhesive to apply. Then using 1/2" on the floor to give it a bit of insulation.
Going to frame the walls about 1" off the foam to allow an air space and then use R13 bats in between the studs.
 
I have done this but I am not finished yet (very slow).
What's usually, done, I've read, for a cold place like NH, would be 2" of XPS foam on wall, stud wall in front of that and insulation in that (no vapaor barrier).
What I did was glue 2" of xps on the wall. Attach furring strips into by screws into hammer drilled holes. Tyveck the joints. THEN, in a move that I invented, lol, I milled out grooves with a wobble dado blade in 2" xps foam boards and glued them onto the first layer, so that there it was flat. On the outside. Very solid.

For wires, on the first layer I used a router with a half inch bit to locate the wiring. I think I screwed in firring strip blocks for the electrical boxes, but it's been so long, I forget, lol.

As far as gluing, I used PL300 polyurethane glue. You don't want to use anything with petroleum in it because that will eat the foam (really, it does, I know). The first layer I held the sheets up with my hands for a while til it stuck. I was trying to think of a jig or something that would provide even pressure, but I never came up with anything. On the second layer I think I used Gorilla glue, which is polyurethane, and is a lot thinner than the PL300, plus I was sticking foam on foam. I used the fact that the furring strips were up and temporarily screwed in boards to hold the second layer to the first layer.

Still don't have the sheetrock up. I know I'm bad. Hopefully this winter after (and if) the leg feels better.

Anyway, it's not that efficient, but it's what I did.

Don't forget to insulate the rim joist area.

It's definitely warmer down there.
 
1x3 firring strips with Tapcon screws. Then anchor drywall to the firring strips as well (need to cover per Code). Tape joints with Foil Tape.
 
I'm in the process of adding insulation to my basement also. When I do this I plan to use the paperless sheetrock that's now available (e.g., DensArmor). I've been thinking of using composite or metal studs also. All this to prevent any mold growth.

What I'd really like to find is less expensive source of foam board. The prices at my local home centers seem exorbitant.
 
FYI, if you haven't already maxed out your $5000 energy tax credit, you have until the end of the year to get 30% back on all insulation. Next year, it's only 10%.
 
CALJREICH said:
It should keep the basement warmer. Are you just wanting to insulate the wall or are you planning to finish the basement? If your not planning on finishing it you could probably glue board onto the walls.
If your woodstove is in the basement it will increase the effiency of the stove I think. Unfinished basements are particularly bad locations for wood stoves because too much of the heat is absorbed by the walls and lost to the outside. So if you insulate the walls you may burn less wood and have a warmer basement.

Half of the basement was finished by the PO, the other side is used for washer/dryer and tools. i won't finish that side just foam the walls and spray foam the ban joist's.
 
All good info, thanks for the help. I'm going to use 2" foam from Lowes and glue it to the walls after I prep the wall of course. Now that we have the pellet stove we don't use the furnace anymore and the basement gets down to 45 degrees so the foam should help allot.
 
Hey my house is on a slate foundation with a dirt floor. Previous owner put up 1x3 nailers and vapor barrier on the walls. The areas around the foundation has been stuffed with pink insulation.
I am not sure if it would help my situation to insulate the walls with still having a dirt floor. Comments/ thoughts ???
 
My concern would be how much humidity you have in the basement with a dirt floor. My level is always 45 - 50% because we have a dehumidifier.
 
The only thing in the basement is the oil tank, furnace and electric hot water heater. We do have plans to finish the floor off, but that stuff is almost as hard as the slate foundation! Some sort of clay or mix of dirt, pita. I want to go down 2 - 3" to level it, put in a stone bed and poor 3" of ready mix or concrete on top of it.
 
That's the one thing i don't like with my house. The ceiling height in the basement is only six foot. At least you have to chance to get a decent height in your basement. I'm a big DIY guy so i would tackel a job like that.
 
livefreeordie said:
That's the one thing i don't like with my house. The ceiling height in the basement is only six foot. At least you have to chance to get a decent height in your basement. I'm a big DIY guy so i would tackel a job like that.

Oh, we are going to do it one way or another. It may take a pick axe and jack hammer and 5 gallons buckets of dirt. But it will get done! :)
 
livefreeordie said:
Any advice on how to install ridged foam on my basement walls? (interior) Will it help keep the basement warmer or is it a waste of time and money

Thanks

If your basement is fully below grade, you would not need as high an R value as you would want in the other walls of your home. The earth is a pretty good insulator below the upper two feet of soil. But getting R10 in your walls would be a good idea. Usually you would not want a vapor barrier, based on modern recommendations.

You could use 2 inch thick foamular or similar, with furring strips. That would be cheapest and take up the least amount of floorspace. If you want more substantial walls, you could put one inch thick foam over the walls directly, then frame a stud wall tight to that. No need for adhesive. I am personally against leaving any space for air to get into in a basement wall. Too easy to get condensation, bugs, or mice in the protected spaces.

Your basement will be much warmer.
 
Ok, here's another question. The po's insulated the ceiling in the basement, if I insulate the walls do I need to remove the ceiling insulation or can I leave it there?
 
livefreeordie said:
Ok, here's another question. The po's insulated the ceiling in the basement, if I insulate the walls do I need to remove the ceiling insulation or can I leave it there?

If you have a source of heat in the basement, I'd remove the insulation, if easy to do. If no source of heat, I'd leave the ceiling insulated. If you don't use the basement much in the winter, I wouldn't bother to insulate the walls, if the ceiling above it is well insulated.

BTW--what sort of insulation is on the basement ceiling?
 
dave11 said:
livefreeordie said:
Ok, here's another question. The po's insulated the ceiling in the basement, if I insulate the walls do I need to remove the ceiling insulation or can I leave it there?

If you have a source of heat in the basement, I'd remove the insulation, if easy to do. If no source of heat, I'd leave the ceiling insulated. If you don't use the basement much in the winter, I wouldn't bother to insulate the walls, if the ceiling above it is well insulated.

BTW--what sort of insulation is on the basement ceiling?

+1 With the ceiling insulated (if well insulated) the only reason I'd look at insulatiing the walls is if I wanted to finish the basement. Still would probably pay to do the band joist/sill plate though.
 
With my foundation walls being slate rock, there are all different sizes and shapes. So, none of it is even or square. Like I said previous owner installed 1x3 nailer/ furring strips and plastic sheathing on the walls.
My wife can tell you that the dirt floor well let moisture out. She has some boxes of decorations down there and when she picked one up the bottom fell out of it. Now, I bought her plastic storage totes.
 
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