Kiln floors

What causes the breakdown of concrete floors in kilns? September 6, 2000

Q.
The concrete floors in our kilns are disintegrating. We replaced the floor in one kiln about five years ago and already it is deteriorating. The floors in our other kilns are going to have to be replaced soon.

Does anyone know what can be done to stop or at least slow down the deterioration? At one of our other divisions, we would spray the floors with kiln sealer, then spread sand over it, but it wouldn't last long by the door. Epoxy coating was suggested, but the cost is horrendous.

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I used that epoxy coating on my kilns several years ago and yes, it was expensive. But it lasts a long time. If I had it to do over I would consider starting with it.

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The basic problem is that the acid in oak and other species reacts with the limestone in the concrete. So, instead of limestone, use river rock for your next floor.

You can coat the floor with epoxy and also sand so that it is not slippery.

Most people familiar with concrete engineering can give you good advice; perhaps go to your local university's engineering extension.
Gene Wengert, forum moderator