06-26-2017, 02:16 AM
So, i'm battling rodents. For reference I have an 1880s farmhouse that was moved in the 1920s, and sits on a brick foundation. The center of the house has a 6'cellar with concrete slab floor and a french drain system around the perimeter, tied into the sump pump (which runs often), all installed before we bought the house. The front and back of the house are large 2.5-3' crawlspaces that are accessible from the cellar, with exposed dirt and a halfhearted attempt at a vapor barrier by the PO. we keep a dehumidifier running down there pretty much 24/7, also draining into the sump.
Due to the brick foundation and old age of the house, our house will never be fully sealed (we've been told that painting a sealant on the inside of the brick foundation is NOT a good idea as it will cause the bricks to degrade due to trapping moisture within them, is this accurate? some have already been painted by PO.). I'm thinking one of the rodent's main points of entry is digging up through the dirt floor crawlspace under the kitchen, so I plan to pour 2-3" rat slabs in all of the crawlspaces, (likely will pour in 8' square sections or something as I'll be mixing by hand and using buckets). We do not use the spaces for any storage whatsoever and do not intend to in the future, so structural integrity or developing some cracks in these slabs is not a large concern, just need enough to keep out the critters. I will not be putting any insulation under the concrete, as the basement is not a conditioned space, but is it worth putting a vapor barrier down first? and regardless of vapor barrier, does one need sand/gravel under concrete for these purposes? the existing earth is relatively sandy, but again, not a structural slab, trying to avoid additional expense if I can. I've been thinking that since the foundation is relatively porous, a vapor barrier under the concrete might not do much, and we do not have any radon issues. all told, I am debating not putting much effort/$ into a vapor barrier or substrate under the rat slab but am happy to be convinced otherwise if this is a poor decision. this is not our forever home, so balancing issue abatement with expense, and not trying to screw over the next owner. Thoughts?
Due to the brick foundation and old age of the house, our house will never be fully sealed (we've been told that painting a sealant on the inside of the brick foundation is NOT a good idea as it will cause the bricks to degrade due to trapping moisture within them, is this accurate? some have already been painted by PO.). I'm thinking one of the rodent's main points of entry is digging up through the dirt floor crawlspace under the kitchen, so I plan to pour 2-3" rat slabs in all of the crawlspaces, (likely will pour in 8' square sections or something as I'll be mixing by hand and using buckets). We do not use the spaces for any storage whatsoever and do not intend to in the future, so structural integrity or developing some cracks in these slabs is not a large concern, just need enough to keep out the critters. I will not be putting any insulation under the concrete, as the basement is not a conditioned space, but is it worth putting a vapor barrier down first? and regardless of vapor barrier, does one need sand/gravel under concrete for these purposes? the existing earth is relatively sandy, but again, not a structural slab, trying to avoid additional expense if I can. I've been thinking that since the foundation is relatively porous, a vapor barrier under the concrete might not do much, and we do not have any radon issues. all told, I am debating not putting much effort/$ into a vapor barrier or substrate under the rat slab but am happy to be convinced otherwise if this is a poor decision. this is not our forever home, so balancing issue abatement with expense, and not trying to screw over the next owner. Thoughts?
-Justin