It's a gypsum product which I have never installed. I have though, removed it from showers which makes me wonder why they would tell consumers to use it in an area where moisture is a factor. Moisture turns this stuff to mush.

Hi Harry
Well..not much chance you'll be getting a free skid of this stuff eh? I've had problems with this product too...it does fail if exposed to repeated contact with water...and the water proof coating on the outside is water resistant..but what good is that if it gets wet on the edges?..where there is no coating? Nice to work with though!