# Insulating Gaps in Crawl Space



## cwk1 (Feb 24, 2015)

Hello-
My floors are cold and I think I'm losing a lot of heat. Around the entire perimeter of the crawl space, I have a 1-2" gap between (on the two sides of the house) the last floor joist and the brick wall, and (on the front and back of the house) between the brick wall and some 2x4's which run between joists. See photos below. One is a view looking straight at one of the 2x4's, and the other is looking directly up at the gap between the same 2x4 and the brick wall. Can I fill these areas with spray foam or do something else to prevent drafts? Any other suggestions?
Thanks!


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## Windows on Wash (Aug 30, 2011)

How old is the home, where is it located, any moisture issues in the crawl, where is the duct work, etc.

There are lots of ways to skin the crawlspace cat but it will depend on several factors.

If the home is well graded and there are not any moisture issues, conditioning the crawl is preferred. Your home may be balloon framed so that will need to be addressed from a fireblocking standpoint as well.


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## cwk1 (Feb 24, 2015)

I believe the house was built in 1956. It is a brick house located in Henrico County, VA just outside Richmond. The duct work and A/C unit for the first floor is located in the crawl space. Crawl space is vented and has a vapor barrier which was placed there for the purpose of radon remediation, I'm not sure how that measures up for containing moisture, etc. I am not aware of any moisture issues.
I don't know anything about framing and so I don't know if it is balloon framed or not, or what is considered "framing" when the house has all brick walls. I know that my attempts to match up the construction I see in my crawl space to any pictures or diagrams on the web were unsuccessful. For example, in my photos you see the joists resting directly on the brick, I don't see any sill plate or anything else. The subfloor reaches as far as the pictured 2x4, after which you can see a gap between it and the brick wall.
It may be that conditioning the crawl space is the best thing, but If I don't currently have the resources to consider having that done, would plugging those gaps do anything to at least help my situation, or would that create other problems?
Thanks very much for your input


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## hthome (Feb 25, 2015)

Definately looks balloon framed. Also, something to point out, with a balloon framed house looking past that 2x4 is looking into your wall cavity. Which tells me that your exterior walls are uninsulated. Perhaps your money would be better spent there on a drill & fill application. Only issue with that is knowing were the fireblocks are if there are any. Yes you can seal that with can foam. Its going to take a good bit of can foam though. Use a piece of cardboard rough cut a little bigger than the opening then foam around the hole and stick the cardboard to it then add a bit more foam.


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## hthome (Feb 25, 2015)

Conditioning most crawls would be your best bet in the long run. Your attention should turn to your walls and attic first though. Seal all penetrations in attic going into living space ( light boxes and fixtures wires going through walls, etc.), then have a contractor insulate to code. With walls, a drill & fill would help with drafts, although fiberglass does not stop air it will reduce airflow into the home. Seal your outlet boxes and switches with caulk and can foam. P.S. Check with county code. They tend to be babies when it comes to radon and conditioning the crawl.


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## cwk1 (Feb 24, 2015)

So I guess conditioning the crawl means that it will become part of the circulated air we breath? If so I'm pretty sure my wife won't have it even if the county will. Honestly I'm not wild about the idea either. I will start by filling those gaps and the others you mentioned to block as much of a draft as possible, and try to determine how much of my exterior walls are uninsulated. Any tricks for determining that without cutting holes in the wall? I'll see what I can from the crawl space but it doesn't always work out as easily as the spot in the picture.
Thanks!


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## hthome (Feb 25, 2015)

Read this, and other research before you make a decision. http://web.ornl.gov/sci/buildings/2012/2010 B11 papers/174_Hales.pdf

As for the walls, we used a combination of IR cameras, IR thermometers, JACKETED wire snaked beside outlet and switch boxes to check insulation levels and search for fireblocks. Do not stick bare copper wire in your wall cavity, you very well may get a painful surprise. Once you roughly locate a fireblock, use a stud finder to mark it. Since the house was built in the 50's I would venture to guess that there is very minimal to no insulation anywhere. In many instances they would use sawdust from the job and put it in wall cavities to get rid of it. I have also seen vermiculite, pearlite, and coal dust ( old train station, nasty stuff) mostly in attics though.


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## hthome (Feb 25, 2015)

If you are set on SPF, Have a 1" lift of 2# CCSPF sprayed on your sublfoor to seal penetrations and the like for air movement. Especially useful if you have a plank sublfoor. Stuff those big gaps (and small gaps) with fiberglass, vacuum all the cobwebs and random crap off of the subfloor, then have an insulation contractor go in to spray. The cleaner you have your crawlspace, the happier the crew will be. Happy crew leads to a good job. (generally, some are still d-bags). 

Edit: After the SPF, insulate with fiberglass batts as normal. Can't tell what size joists are from pictures. Use lathe or poly twine to hold the fiberglass up.


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## Gary in WA (Mar 11, 2009)

Sounds as if you have a brick veneer (on exterior) and wood frame wall inboard of that. The wood frame wall should be insulated, not the air space between wood/brick or you will cause new problems. A picture of your window jambs (sides) from inside (and showing some brick), about 3-4' away would tell us if veneer or not. Are there any weep holes at dirt level in one course of bricks on exterior side; https://www.google.com/search?q=wee...uses-solid-masonry-vs-brick-veneer%2F;450;360

http://www.buildingscience.com/documents/reports/rr-9909-drainage-planes-and-air-spaces

Gary


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