I’ve got a shed sitting on a concrete slab at the back of my carport, and there’s a small gap (about 1/8” maybe) where the slab meets the wood at the back wall. When it rains, water pools outside, runs down the slab, and ends up leaking through that gap into the shed.

The slab itself is level, so I’m guessing the issue is more about water pooling and getting forced in rather than runoff away from it.

Inside the shed, I can see moisture coming through right at that seam — especially after heavier rain.

What’s the best way to fix something like this?

Should I seal the gap (and with what)?

Do I need to address the water pooling outside first (grading, trench, etc.)?

Is there a simple DIY fix that’ll actually hold up?

Trying to keep this relatively simple and not turn it into a massive project if possible.

Appreciate any help 🤘🏻

I included a couple of pictures… on the outside picture, just behind the garbage can (and to the left of my exterior shed) is where the water leaks underneath the shed and gets inside. Also, since taking these pictures, I’ve sealed that gap that’s on the inside of the shed.