Cement backer board and shower curb

[zippy48]

Can cement backer board be applied directly to a cement shower curb using thinset to give a nice level curb in which to apply ceramic tile? I know that it cannot be nailed due to the shower membrane beneath the cement.

[proszkow]

Dont think so. CBU needs to be screwed in place.

Why isn't the curb cement smooth?

You may be able to smooth it by applying a thin layer of thinset.

Alex

[John Bridge]

Hi Zippy, Welcome aboard.

You'll need to level out your curb with some sort of cement product, either thin set or more mortar. Backer board does need to be screwed or nailed.