airtight crawl space door?
BrunoF
| Posted in General Questions on
I am planning to have a sealed and insulated crawl space in my new house and would like some recommendations on air-tight crawlspace door options? Does such a thing exist or am I likely to have to fabricate something?
THX
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Replies
If access to the crawl space is from the interior of the house this could work: https://www.batticdoor.com/product/ez-hatch-attic-access/
I have done this for exterior access doors by jut building a jamb as I would for an exterior door with weatherstrip and an aluminum sill. I strongly suspect there is an off the shelf item but this was pretty easy to accomplish with stock material.
Keep in mind that you need to provide some ventilation with conditioned air to a sealed crawlspace, so that makes an airtight access hatch questionable in terms of usefulness in many cases.
Bill
I've used a chopped down standard door for this. But as Bill points out, for a conditioned crawl, you don't want an air tight door, it should be connected to the house.
Bill and Akos are right, it should be accessed from inside the conditioned space since it is conditioned as well.
Don’t forget to provide an air supply rate of 20 CFM per 1000 sq. ft. of conditioned crawl space: https://basc.pnnl.gov/home-improvement-expert/checklists/vented-unvented-attic#:~:text=HVAC%20supply%20and%20return%20air,the%20amount%20of%20living%20space
just to clarify...I am referring to a small door that is essentially on-grade and that will provide access from the exterior into the crawlspace. There is no way to access the crawlspace from inside the house. regarding the conditioned air...I know I needs supply air but I figured that it would return to the floor above with a small duct. Also, the air handler will be in the crawlspace (all electric) if that is of any significance.
thx
Bruno,
Why do you want to access this from the outdoors? You should avoid having exterior fenestrations whenever possible to maintain the integrity of your air barrier. You can get creative with access hatches to your crawlspace, see the attached image for one example. Do you really want to have to go through the outdoors to change filters on your air handler?
If you have the air handler in the crawl, I would look at at an access panel in the floor of a closet where you can directly reach down to change the filter or design with a filter grill on the return instead.
matthew25,
A lot depends on the topography and what you want to use the space for. Around here we have many sloped sites where you end up with what you might call a walk-out crawlspace, high enough at one end you that can stand up. They are perfect for storing tools and other things you would prefer to keep in a condit0ned space, but wouldn't want to drag through the house.
We don't usually decide not to include an exterior door where it is appropriate in the living area of a house over air-sealing concerns, so I'm not sure it's good enough reason not to have one on a crawlspace.
My suggestion was for the small door. Take an exterior door and chop it to size. With a steel door the bottom won't be pretty but you can cover it with one of those U shaped door sweeps.
You can also use a largish slider window.
If you have the space, you can excavate for an exterior set of stairs, use a regular door cut to fit as Akos suggested, and use a set of bilco doors for weather protection on the exterior. I have an outdoor basement access done this way, which is very handy when bringing large things (like 10 foot sticks of pipe) into the basement. Using a regular door makes it easy to use regular compression-type weather stripping that tends to be reliable.
Another option would be to build a sort of sideways version of the good attic hatch designs, which typically use draw latches and compression weatherstripping. I would put hasps on such a door though, with carriage bolts (so they don't have an external bolt head that would make them easy to defeat), so that you can lock the access hatch.
Bill
Similar situation. Access to conditioned crawl via opening in CMU and I had to seal it.
I installed PVC door jamb material on all 4 sides - the door jamb material has a compressible seal.
Then ordered an insulated fiberglass flat face door from a door fabricator. They are used to making these because they are often used for attic access. I had to call around to find one who would do an insulated fiberglass - most just wanted to do hollow hardboard because that is what they use for attics (even though they should insulate them).
Found out later that this door shop would have fabricated the door prehung on PVC jamb at a custom size if I had asked them to. That would have been easier because they would have done the hinges and lock prep...
Also, mine opens out, so I ordered stainless steel non-removeable pin hinges so it can't be broken into by removing the hinge pins, and won't rust. If you want to go that direction be sure to acquire the hinges first so you can direct the door shop to prep for that particular size and shape of hinge. NRP hinges are usually at least 4" square and most door shops use 3.5" rounded.
I've got weather gasketed doors from a company called Custom Covers. Everything is custom sized, which was good for a cut-in retrofit, and they are a drop-in tilt panel with latch hasps and don't have hinges. Welded aluminum frame with a choice of poly or R3 insulated powdercoated steel door.
A bit pricey, but great aesthetics if you're going for modern/minimalist. It does kinda look like a coal chute in black, admittedly. I didn't want any trim though.
It's about 36 x 26 inches for size ref, so a bit bigger than a coal chute. They'll make you any size you want.
Thx! I wish I could access the crawl through the house but it isn’t possible in my design.