Pouring Hearth Slab

[rodeair]

I am ready to pour my hearth slab which will be about 6.5 x 7.5 feet. My question concerns the gaps around the plywood and small gaps between the form and a few of the block. Do I need to fill the gaps with something, or will the concrete stay out of the smaller gaps?

[Paul in Rockwall TX]

depends on the size of the gaps and the size of the aggregate in the concrete mix. If it's peastone, the the gap should be smaller than that.

[dmun]

Duct or masking tape will fill any voids. It may not be necessary, but it's impossible to fix once sludge starts running down the sides of your forms.

[rodeair]

Thank you for the replies. I will use my favorite product in the world, (duct tape) to be safe. The concrete truck is due tomorrow morning so I'll post the results on my thread in the Pompeii Construction section. I very much respect both of you guys. Thanks again.

Leigh