Designing Kitchens and Bathrooms - shower pan - (pressure treated wood)

I have a Home Depot DIY (Tiling 1-2-3) book on how to build a Custom shower pan. it says to build the threshold using pressure treated wood.

is it necessary to use pressure-treated wood? i thought pressure-treated wood is mainly used for outdoor use. Never for indoor use.

thanks

If this is inside I cant see why you need P/t wood. you will put the vinyl pan liner down then the cement. Use cement board on all the walls for the tile.

ED ;)

The instructions are based upon your building the dam out of wood and they are correct. Lumber grade material in direct contact with cement is required to be treated to prevent the intrusion of pests.
However, were you to cut 3.5" wide pieces of wonder board and stack them where you want the dam to be, attaching them together as well as to the floor with pour-rock and a few tapcons thrown for good measure, you wouldn't need the pressure treated.

Yellow pine 2x4's are used everyday for this sort thing without any failures.The way the pan is consructed the wood is not in direct contact with the cement.You do a prefloat for the pan about 3/4 inch all the way around down to nothing at the drain then the liner and then the float for the pan 2 inches at the perimeter dropping a 1/4 inch per foot to the drain :cool: