Zip Sheathing on Vented Crawlspace Walls
New to GBA and have been browsing the site in search of answers to the many questions I have for my residential full remodel in Southern Los Angeles. Currently have the building torn down to the studs interior and exterior and am at the stage where I will be putting up sheathing soon. The goal is to get the interior very well air sealed and make the home as efficient as possible in a budget friendly way.
Sloped plot which makes the “crawlspace” (basically an unfinished basement) about 6ft tall on one end and 4ft on the other.
Original design was a vented attic and crawl space
Converting to all electric
Attic space will be left as vented
7/16″ Zip Sheathing
Rockwool 1.5″ Comfortboard 80 Exterior Insulation
Got a great deal on enough 7/16″ zip sheathing and rockwool comfortboard 80 for the exterior walls but my main question currently is how to address the crawl space. It seems like it would be a waste to put the zip system on the crawl space exterior walls, only to cut a bunch of holes in it for vents. Likewise, exterior insulation in the same area seems pointless if the walls have vents in them. But I also don’t see a need to have the crawl space be sealed and conditioned due to the climate we have in Los Angeles. Maybe I’m wrong?
Can I simply put the zip over the entire house and just leave the crawl space unvented without truly encapsulating it like a basement? Due to the large size of the crawl, I intend to put a heat pump water heater and the HVAC interior air handler + ducting all in the space. I figure the heat pump water heater would help to dehumidify the crawl, especially if I vented the exhaust to the exterior.
I’d love input as to what the best practice for this situation should be and reasons why I should or shouldn’t vent the crawl space. What’s the best bang for the buck? Thanks in advance for any advice or resources to turn to.
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