Pouring Rat Slab for house on pilings with suspended skirting
I have a property at the jersey shore built on pilings with sand/dirt under the house. From what I can tell the walls surrounding the crawl space are “free hanging” from the outer joists resting on the pilings. The walls have flood vents in them so the area is well vented. We are getting some water coming under those walls on one side. That is likely a grading issue I will be fixing regardless. I want to pour a rat slab that will provide a vapor barrier, keep any water from coming in and make sure the water runs out if and when it floods. Ideally would like to pour the cement up and around the base of the 2×4 framing to provide a good seal but concerned about the additional weight it would put on the free hanging walls. Anyone have a good recommendation on how to handle this situation?
Replies
Pouring concrete against wood framing is an invitation to trap moisture and cause rot. Even if the framing is pressure treated.
Address the water entry by diverting it on the outside and if you pour a rat slab keep the concrete away from the wood.
thanks for the feedback. Will definitely regrade the outside but want the rat slab for storage under the house. Thinking I’ll put a 1 ft offset of gravel from the wall with the slab sloping toward the outside walls so when it floods it has a place to drain back into the ground. In your opinion, does that make most sense?
You can install a perimeter drain similar to what is done in basements or, if you go the gravel route, you should should bury perforated pipe below grade around the entire perimeter and run one or multiple ends away from the house to daylight.