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cbaur88 11-29-2011 09:38 AM

Crawl Space/Foam Insulation DIY
 
2 Attachment(s)
Let me give a little background and sorry for the length. Last year After spending much more time in my living room w/ my now 1yr old daughter I've noticed how much cooler and drafty the room felt compared to our other living spaces (split level home). After pulling my hair out and ripping the trim down around our bow window (see attached photo's) which I felt was contributing much to he issue and insulating it the best I could with spray foam, caulk, etc.. the problem still existed. The room was just colder, I swear I feel the slightest draft laying on the rug. The rugs itself are cold without a doubt. Anyways I realized 100% after thinking about it (I never said I was smart) & visiting the crawl space that it was the culprit. First off the batts are installed backwards, all the paper is facing down and visible. Also while inspecting it further I see tons of gaps and holes and some of the batts simply not secured between the joists and falling out of the joists and touching the ground. The crawl space is also vented or lets say it has vents, however the previous owner blocked the vents with batt insulation closing off the ventilation. He's even put up some insulation on the cinder block foundation, which I read is a no no for vented crawl spaces. The crawl space itself seems to be in good condition, not much moisture at all in the dirt, pretty dry for the most part throughout, no signs of mold or anything to worry about.

Looking to do the job myself and seeing the work involved w/ reversing the batts and re-installing them buying some new. Spray foam seemed like the quickest, easiest, & air tight solution. My question for the forum is are some of the DIY spray foam solutions I've seen online worth it or any good. Is one more recommended then the other? Besides spray foam would you recommend another type of solution? I've also reached out to some local spray foam contractors to get a price for a pro to do it, but scared to death to see the quote, lol. Thanks in advance :)

Windows on Wash 11-29-2011 10:16 AM

You are straddling both options in your current crawl space arrangement. It needs to be either insulated to the outside wall and treated as conditioned or insulated under the floor.

If the ground is not showing much moisture, you can likely get away with a conditioned crawl.

http://www.buildingscience.com/docum...erm=crawlspace

cbaur88 11-29-2011 10:25 AM

Quote:

Originally Posted by Windows on Wash (Post 781308)
You are straddling both options in your current crawl space arrangement. It needs to be either insulated to the outside wall and treated as conditioned or insulated under the floor.

Without a doubt it needs to be insulated under the floor. Even though the vents are covered cold air is still getting in making the crawl space extremely cold.

Windows on Wash 11-29-2011 12:00 PM

Did you read the link that I sent you?

When you treat the crawlspace as "conditioned" you are going to seal up and insulate the exterior walls and supply some amount of conditioned air to the space.

You either insulate the crawlspace ceiling.....or.....the outside walls.

Not both.

cbaur88 11-29-2011 12:05 PM

Quote:

Originally Posted by Windows on Wash (Post 781352)
Did you read the link that I sent you?

When you treat the crawlspace as "conditioned" you are going to seal up and insulate the exterior walls and supply some amount of conditioned air to the space.

You either insulate the crawlspace ceiling.....or.....the outside walls.

Not both.

Yes the link was read and I completely and utterly understand you either insulate the walls or the ceiling. The house was built with vents around the foundation of the crawlspace so one assumes it was meant to be unconditioned which is why I would re-insulate the ceiling properly and reverse the batts or use foam. The previous owner appears to have done a no no by insulating everything vents, ceiling, walls, etc....

Windows on Wash 11-29-2011 01:09 PM

Crawl spaces are almost unilaterally built as vented, however, this does not mean that is the best approach.

Most customers will get far better efficiency and comfort by converting their crawl space into a conditioned crawl.

We convert vented crawls into conditioned crawls all the time.

cbaur88 11-29-2011 02:03 PM

Thanks Windows on Wash, that's very interesting to know. With that said I really am not sure which direction to head towards then. My main goal is to prevent the living space above the crawlspace from getting cold and drafty as it is now. I am not sure what you would call my crawlspace as of right now. As previously mentioned it's got vents but they are blocked. The wall of most of the foundation is insulated as well as the ceiling. Which direction to go is or what exactly to do I am at a loss right now.

Gary in WA 11-29-2011 10:24 PM

Some reading to help you decide: http://www.advancedenergy.org/buildi...l%20Spaces.pdf

As per Code if you go with conditioned (requires air supply ducting in crawl); http://www2.iccsafe.org/cs/committee...E_06_64_07.pdf

Cover the exposed dirt with plastic, notice the vents mentioned as WW said: http://dirt-crawl-spaces.com/crawlspace-dirt.html

Some new ideas/science, with more links at the bottom: http://www.buildingscience.com/docum...n-crawlspaces/

Gary

CrawlSpaceMoist 12-07-2011 08:39 PM

Yeah, you've got a couple of decisions to make.
The cheapest route is to go back to a vented crawl - remove the insulation from the vents and walls and fix it in the joists. Make sure you've got a poly down on the floor from wall-to-wall.
The better answer, especially for cold, drafty floors, would be to truly seal this crawl. Remove the crappy insulation from the vents and seal them with a rigid insulation cut down to size and caulked in place. Take the insulation off the walls and either afix an about R10.6 rigid insulation or a wrapped fiberglass (if you can find some). Go around your sill band and caulk, if nothing else where you can see light from outside.
Most state codes require either joist or wall insulation, but don't specifically prevent both being in place, a quick call to your code enforcement division will clarify. Also, codes require a sealed crawl space be conditioned. There are many ways, but either with a dehumidifier or using hvac air are the 2 most common. Oh, and don't forget that poly on the floor!

cbaur88 12-08-2011 09:18 AM

Quote:

Originally Posted by CrawlSpaceMoist (Post 788551)
Yeah, you've got a couple of decisions to make.
The cheapest route is to go back to a vented crawl - remove the insulation from the vents and walls and fix it in the joists. Make sure you've got a poly down on the floor from wall-to-wall.
The better answer, especially for cold, drafty floors, would be to truly seal this crawl. Remove the crappy insulation from the vents and seal them with a rigid insulation cut down to size and caulked in place. Take the insulation off the walls and either afix an about R10.6 rigid insulation or a wrapped fiberglass (if you can find some). Go around your sill band and caulk, if nothing else where you can see light from outside.
Most state codes require either joist or wall insulation, but don't specifically prevent both being in place, a quick call to your code enforcement division will clarify. Also, codes require a sealed crawl space be conditioned. There are many ways, but either with a dehumidifier or using hvac air are the 2 most common. Oh, and don't forget that poly on the floor!

Great excellent advice CSM, I really appreciate it. I'll take a peak at my twps website to see if I can find any codes for when I one day sell my house.


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