Sill beam buried, method of uncovering for ventilation
At the wise direction of some folks here, I explored what was covering the exterior of my 150 year old sill beam before spraying it with closed cell to ensure it could dry outwards.
I discovered the worst, that’s it’s been covered in dirt and concrete. Someone poured a sidewalk maybe 2” away from it leaving a small gap, which of course was filled with dirt and debris over the years.
I have to get moved in, so I plan on continuing the encapsulation of the crawl space and then jackhammering the sidewalk away. I plan to leave an open air trench around the sill beam/stone foundation and cover it with a wrap around wood patio/deck.
My question is, how can I cover this area and prevent water from entering while maintaining dryability and good airflow? My semi conditioned air from crawl space will be exhausted into/through this area as well.
Thank you all for saving my foundation and any additional help.
Edit: maybe this is a grading issue. The footer is incredibly shallow, the house basically sits on the ground :/
photo attached, scribbles due to paranoia 🙂
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It sounds like you need to lower the grade around the house. That would be (approximately) digging down 4-8" below the sill all the way around the house, and then something like a 3-5% grade away from the house extending out 10'.
If you have limited funds I would spend the money on having an excavator come out to regrade (1 day job) and then save up again for the insulation. Hopefully the sill is not rotted.
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Surprisingly everything I’ve inspected looks pretty decent given the age. The foundation on this house is insanely shallow. If I excavated 8” below the sill I think it might fall over lol.
But that does make sense. I’m not sure how it’s stood up so well and so long with this “footing”
Yeah, that's just a general guideline, there are more exceptions than rules - that's for sure.
It sounds like there is no foundation at all? Is the sill sitting on dirt? You could easily be on a gravel wash or the like.
I can tell you there are gravelly loams (Howard soil series) in upstate NY (4 foot code frost depth) where you can scrape away a couple inches of top soil, dry stack some stones and your wall won't move a millimeter until the next ice age when everything is swallowed up again. There are other soil types where even going 4' down and putting in a 2' wide footing, the frost action could still push the building around over time.
There are big flat rocks probably 8-10 inches tall that appear to have been cut and the sill beam (8x8) sits on top of that. It looks like some small flat rocks might be stacked below them, but maybe only a couple inches. I’d say the concrete and dirt covers the lower 3-4” of the 8” beam.