# rim joists



## joecaption (Nov 30, 2011)

#1 post a picture.
#2 Most likly you have what's called ballon framing. It all needs to be fire blocked before doing any insulating. If the walls are over 8" tall your also going to have to fire block in the middle of the walls.
If you key word search on this site you will find lots of info on fire blocking.

The reason for the blocking is in most cases that wall is open from the basement to the attic which makes a great chimmney when there's a fire. It also sucks cold or hot air all the way from the bottom to the top of the house through the walls.


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## hammerlane (Oct 6, 2011)

Can you use spray foam for the rim joist cavities??


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## Windows on Wash (Aug 30, 2011)

Well said Joe.

Fireblock and a combination of rigid and spray foam usually does the trick after that.


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## cristorucci (Aug 15, 2012)

In this situation, where there are two small openings into the wall above, what measure of fireblocking would be required. Can I just seal the holes and then insulate? It is a stone foundation. Does anyone have a good recommendation for an insulator. Am I allowed to ask this? I live in Brooklyn, NY.


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