Recommended Porch Slab Height
What is the best height for a front covered porch slab in relation to the main home slab? I had planned on pouring it 2 1/2″ lower to prevent water intrusion. I’m wondering if that will feel too high as one enters the home.
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Anywhere from flush to a 7" step is common, but there tend to be regional preferences. Here in snow country I usually aim for a 4-6" step, unless wheelchair access is required.
If it's a generous porch water intrusion will be less of an issue.
Consider finish floors. Will the porch slab receive tile or stone? What about the interior?
If you're installing the entry door sill on a slab, you could consider a 1/2" recess in the slab, to serve as "sill pan" of sorts.
As Michael Maines mentioned, setting it high will allow wheelchair access, something people may not think they need now, but might well need in the future.
I happen to be wrestling with that same issue right now. Here's a detail that is still very much in progress. I've made a 2" recess in the slab and put down a pressure treated 2x6 to simplify the nailing of the sill and to provide support for it as it extends over the 2" of slab edge insulation. Then I've set the porch slab so that the finish stone, 1" thick, can slip under the sill.
It's not strictly ADA compliant but doesn't need to be and can easily be managed in a wheelchair.
One recommendation is avoid a small step. It should be either mostly flat as suggested in #2 or a stair rise height.