How to Insulate and Seal a Rim Joist- DIY Weatherization for Your Home

Using Closed-Cell (or High-Density, or 2 lb.) expanding spray foam, Corbett demonstrates how to both seal against air leakage and insulate at the rim/band joist that runs around the perimeter of many homes, at the top of the foundation wall.

Category:

Howto & Style

Tags:

• weatherize
• weatherizing
• home
• energy
• draft
• improvement
• green
• rim
• joist
• band
• spray
• foam
• insulation

[GreenDreamGroup]

The camera we use now is the Fluke TiR, but in the video we had the FLIR BCAM.

[EricL5150]

Do you have to put a barrier of sheetrock after you're done spray foaming or can you just leave it? I know that if you use rigid foam board, you need to have a barrier of some sort after you put the rigid foam up.

[GreenDreamGroup]

Great point, Eric- fire code may require some sort of fire barrier over the foam, which can be a special paint, or drywall.

[graylyns]

Do you do the same thing if joists are on concrete slab?

[GreenDreamGroup]

Hm. Maybe, but not likely. The rim joist is a weak spot on stick frame homes, but the concrete wall is the same thickness at the wall and at the perimeter of the floor joists.  We have seen air leakage at the joist penetrations, but we wouldn't prescribe this approach generally.

[d1incharge]

This is one of the very few times I have understood the use of foam. Enough time savings and hard to reach gaps to justify its use. I have a feeling if you were to cut pieces of faceless r-19 properly, throw them in plastic grocery bags and tuck them in there neatly, better r-performance for less+air seal. I have seen many two stories where the floor joist were open through both sides to the attic, thats when I pull out that particular trick, except using r-30. Dig the basement. BPI or HERS?

[GreenDreamGroup]

Yeah, it's great in some applications. The plastic bag trick works with batts, but you still have to foam around with one-part spray foam, just like with rigid board. Both BPI and HERS- they complement each other well!

[zeekle]

Your basement is cool with those lights!

[jumpthehoops]

I like your video - very informative. I am also interested in the thermal imaging camera you used... Do you have a make/model for it?

Cheers!

[smstudios233]

The cc foam is much better than batts, even bats in bags, because it sticks to the surface and guarantees all the little penetrations are filled and air tight. You can also cut blocks of rigid foam and use little cans of foam to seal them in. You should fill the entire rim joist cavity (to the outside of the wall).

[tquibido]

I would recommend using the Zerodraft A&B foam tank... It works great for everything.

[mywindlock]

Great video! Don't forget that you can also use Dow's easy-to-use Froth-Pak to insulate and seal a rim joist. Check out our channel with another video on sealing this very important area of any building!

[dtThurman]

That looks like a "FLIR" BCAM, about $4500.

[TreeTrunk82]

where did he get that infrared device? and what is the proper name for it?