Another crawl space in the Northwest
Hello all, I have a 1150 sq ft rambler house in Fall City, Washington (near Seattle), zone marine 4c. I am currently in the process of redoing the crawl space. I have pulled the damaged and rodent infested insulation down, and removed the town vapor barrier. It seems I had some rodents that were digging past the foundation and getting into the crawlspace, ruining everything.
The crawlspace is tight, 18″ to the floor joists and uses the old style post and pier construction method of 4×6″ joists 48″ on center with 2×6″ tongue and groove on top, with hardwood floors finishing off the floor.
After cleaning up the crawl space I started doing research into how to insulate the area, and found the encapsulation method. I like the method due to not having to run insulation in the floor joists, giving me more space to work down there, and also in keeping the area cleaner for rodent inspection purposes and for when I do plumbing or other type of work.
The house currently has baseboard electric heat, though we are thinking of going to gas forced air. I had a recommendation from an HVAC installer to put the furnace in the attic, which will make it difficult to heat the crawl space. I would prefer the HVAC be in the crawl space, so the ducts don’t have to be insulated and the heat from the ducts would be used to heat the crawl space, though with the tight clearances, that would make access down there much more difficult. 6 of one, half dozen of the other.
Also, the issues of increased Radon exposure also has me worried. I
Some research I have seen shows that in this area (zone 4c) vented crawls spaces do a pretty good job.
1) It seems an exhaust fan in one of the crawl space vents with a floor register in the house (preferably opposite side from vent) would be enough to heat the crawl space with electric base board heat?
2) If I get HVAC in the attic, would it be preferable to run a heating duct to the crawl space (close off floor register) and keep the exhaust fan?
3) Would the exhaust fan be enough to mitigate the Radon issues? It seems most encapsulation projects don’t include Radon abatement issues. I am pretty ignorant on this subject, but I have three little kids under the age of 5.
4) Is there anything else I need to take into account or that I haven’t thought of?
Thanks everyone for your time!