Concrete Slab - pour over old piers?

I wouldn't leave them there.

How deep do they go?

Covering them, might cause a weaker slab in that area, and could crack easier, if you get much frost depth heave.


ED

Clay is famous in tx area for ruining many foundations. Dry/wet cycles. Could do the same in your area. Also check mike haduck's youtube videos about separating slabs from other parts of a structure. Your slab will move and the anchored parts on those piers will crack. I'd sledge hammer about a foot and bury the rest. That way, the slab is in one piece and moves on its own.

A soil enginere wouldn't be guessing what the soil make up is but would rather test and you can too. And your cost will be the least expensive part of your project as that cost will approach $0.00.


I wouldn't allow he piers to remain unless they could be covered at least a couple of inches with compacted fill.

What carpdad said, that will get you one solid pour.

Are you not planning to use any aggregate bedding?

Thanks everyone for the advice and the references. I'll remove the piers, makes sense. I wasn't planning to use an aggregate base, as we have pretty mild temp changes in So Cal (no freezing), and I will be tieing in plenty of rebar.

FYI it helps to have your location shown in your profile, so we can have an idea of your climate without having to ask.

huesmann said:

FYI it helps to have your location shown in your profile, so we can have an idea of your climate without having to ask.

Click to expand...

I second that, in your USERCP ( upper left), find the Profile box, and fill in the questions that you are comfortable divulging.

Your location will be permanently added to your posts on the left.


ED

Got it. I'll add my location. Should have added that at the start. Thanks.