Why dont I need to dig footer below frost line?

[Pompeii Nate]

Re: Why dont I need to dig footer below frost line?

So I have more gravel questions now. I followed the FB plans and have been putting down pea gravel (approximately 8" so far) but a friend told me that it isn't the best stuff to use. He mentioned that road base is better because it fills in all the cracks and gaps. My concern with the road base is how much dirt is in it and if the gravel is for drainage why do I want all that dirt in there? Does that make sense? I really don't want to take out all that I have compacted down so far. Help!?

Also, I heard that using 6mL of plastic causes the concrete to "curl" on the edges so I was told to go with the black gardening fabric as a barrier and told that will do better. Thoughts?

Nate

[Laku]

Re: Why dont I need to dig footer below frost line?

For keeping the slab dry, not filling out the gaps and cracks is better. If the gaps and cracks get filled then water can climb to your slab by capillary action.

[Mingy]

Re: Why dont I need to dig footer below frost line?

Nate
I believe they use pea gravel specifically because it doesn't compact which allows the slab to drain. So, my basement floor its (top to bottom) concrete, 6 mil plastic, 2" styrofoam, pea gravel, rock hard clay. I believe for your application you'd want compacted fill. I put a layer of geotextile between the ground and rock.

I replied to your PM about the plastic. In this area, its considered 'best practices' to put plastic under concrete. I did find one article which suggested that, in very dry climates, it negatively impacts concrete curing, presumably because the bottom of the concrete can't get moisture from the ground. Here, you usually 'mist' curing concrete if drying is an issue (only after it is hard).

[suzie queue]

Re: Why dont I need to dig footer below frost line?

Hi Mooch, I just saw your post and I am sure you are done with your kitchen by now but here are my thoughts for someone else wondering about the same question:

I am in southeast Ohio so the weather is similar to Pennsylvania. I had a regional builder of metal buildings build my work shop. Since you built a kitchen for your oven, I am assuming this is an enclosed building?? If so, the building technique my builder used was a "post" building where he used pressure treated posts in the ground placed on top of concrete footers under the posts (a bag of Quickcrete); left the holes open, then they poured the reinforced slab (which was on top of a leveled gravel base, which was in turn, on top of local "bank-run" which is a sandy-gravely dirt mixture dug out of river banks.) The concrete filled in the rest of the post holes as the posts were inside the completed building and therefore, part of the completed concrete floor. After completion, we then insulated the metal building in the walls and ceiling. It never gets below 40 degrees F inside and the floor never cracked (unbelievably!) after the pour. I guess because it was in shade and we kept wetting it down during the cure.