Crawlspace encapsulation help (take 2)
As I continued my reading and tried to find “pros” with nice tools like an hilti Gx-IE to come to my aid, I have come up empty, left with more questions. I am in 4A climate zone
after spending a great deal of time in my crawlspace that has lose laid plastic some black some white. I am trying to come up with the most cost effective and manageable install.
It seems I will have to have my foam board covered for my application, but this leaves me with an issue. for the cost of the fire retarder / barrier in drywall or cement board, etc.. I could use a contentious layer of mineral wool screwed in to furring strips and get another r8 to r15 on my crawlspace walls. The thing is
Martin Holladay seems to be against any type of batt insulation in a crawlspace.
If this the mineral wool over foam approach is do able, I could save a huge chunk of money by only using R5 foam. It would help in installing too. horizontal furring strips could be installed with a powder actuated fastener vs hammer drilling. The furring strip + foam board would act as a mechanical fastener keeping the poly and adhesive tape product sealed to the wall. I read a post calling this an hybrid approach. It seemed to work and not matter in my climate about due point and foam thickness.
Does it matter from a long term point of view if I use powder actuated fastener vs hammer drilling for concrete block? I don’t think drilling in 18″ of crawlspace (before joists around 24″ deep.) will be fun, at the least it will be slow moving lol.
Whats the deal with the poly sheet and the wall? I get an overlap to keep foam from contacting the ground and to seal the edge for moisture. The thing is I have read so many papers and companies install sheets.here is the summary:
poly all the way up the wall, then foam.
poly 6 to 12 inches up wall then foam.
Foam then cover it up the wall with the poly.
No poly on the wall the foam is fine by its self.
termite inspection strip, I cant seem to find code on this, but I am not in the very heavy zone. just moderate to heavy. I don’t see an issues nor did my home inspector before buying. Is it best practice to just leave that 3″ gap?
Water and foundation:
I have installed gutters. atm they are 6+ feet out, working on underground drain to ditch.
I have fixed any grading issues and the land is sloped away from the house on all sides. I would like to add more fill but that is another topic another time.
I dont see any water issue in the crawl, but it is below grade a few inches.
Should I paint / add water sealer to the outside of the concrete block?
Am I over looking anything?
Thanks for your time, hopefully I can come up with a finalized plan.
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