Hearth Concrete

[ftaylor74]

Hi all!
I'm not sure what happened to my first post on this subject, but I'm hoping that I'll have better luck this time.

I am about to mix and pour the concrete hearth slab for my Pompei style oven. I am planning to use Sakrete High Strength Concrete for the hearth slab. I believe it is a gravel-sand-portland cement mix, in a 3-2-1 ratio.

Is this the same sort of mix that everyone is using, or should I be looking for a sandier mix? If so, what are your suggestions?

Thanks

[Art nj]

Re: Hearth Concrete

I used sakrete gravel mix on mine, worked great..

Art

[NCMan]

Re: Hearth Concrete

Hi all!
I'm not sure what happened to my first post on this subject, but I'm hoping that I'll have better luck this time.

I am about to mix and pour the concrete hearth slab for my Pompei style oven. I am planning to use Sakrete High Strength Concrete for the hearth slab. I believe it is a gravel-sand-portland cement mix, in a 3-2-1 ratio.

Is this the same sort of mix that everyone is using, or should I be looking for a sandier mix? If so, what are your suggestions?

Thanks

That should work fine. If you are interested in helping the concrete to gain even more strength, use as little water as you can (use enough to make it workable, though) and give it a nice, slow cure. Excessive water in the mix weakens concrete and lessens the PSI of it. You can start out with 5000 PSI mix and end up w/2500 simply by adding too much water. The longer you can keep the moisture in the concrete, the stronger it will be. I cover mine w/plastic to retain the moisture for a few days and cardboard to block the light/sun and to help retain the heat that freshly mixed concrete produces naturally. Of course, a good base, proper thickness and adequate reinforcement are also important. Having said all that, your oven slab isn't going to crumble and fall apart if you don't do these things. It'll just be stronger....that's it. Just my 2?.

[david s]

Re: Hearth Concrete

Adding some super plasticiser to your brew will also reduce the amount of water used and retain good viscosity, but you need to calculate the correct amount, don't just throw it in by guesswork or you can end up with separation and wreck the mix.