Faswell Crawlspace
mowich
| Posted in General Questions on
Hi there. I recently purchased the shell of a timber-framed cabin on the Olympic Peninsula in Washington State. I am trying to sort out the crawlspace. From what I’ve read it sounds like I can/should get away with a vented crawlspace given its geo. But it’s got a layer of Faswell on top of the concrete foundation and given how permeable that is, is it advisable to spread a layer of s-type mortar or something(?) on the exterior and then vent through in a couple places? Can’t seem to find any info specific to this use case, so appreciate any advice. If I can provide any additional details, let me know. Thanks!
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Replies
What is Faswell?
https://faswall.com/faswall-block-structure/
I would love to post a picture of the cabin to demonstrate exactly what I'm talking about. But I've been trying all morning to upload one here and it just keeps erroring out. Will keep trying
Ah, googling "faswell" showed a company that makes Velcro.
Is your image under 3MB? Sometimes when they are even close to 3MB they won't load.
I never recommend vented crawlspaces, unless they are a pier-type system with a ton of airflow. There is just too much risk of condensation and mold in a conventional vented crawlspace. You might be able to get away with one as dewpoints in the PNW tend to be low, despite all the rain, but personally I wouldn't risk it.
Okay, think I got the picture added (had to go way below 3mb, thanks for the tip). And apologies for my original mispelling of Faswall.
So then if the advice is to air seal it, then the follow-up is whether there is a recommended approach for sealing Faswall. My google'ling doesn't turn anything up...
It looks like they have information here: https://faswall.com/basements-foundations/.
This is a good overview on what is required when sealing a crawlspace: https://www.greenbuildingadvisor.com/article/building-an-unvented-crawl-space.
Tell us about this Faswall stuff. Does it need to be protected from the weather? Can it be buried? Is it permeable?
I recommend this article for an overview of crawlspaces: https://buildingscience.com/documents/insights/bsi-009-new-light-in-crawlspaces