Pressure treated 2x4s for shower curb a no no?

[snokel]

Been doing a bit of research and everyone seems to say not to use PT lumber for the shower curb over
concrete(in a basement) however after having several very heavy and wet PT pieces sit for a couple of months along with standard KD lumber (has the KD stamp) the standard KD has warped and twisted much more than the PT
2x4s

 

[Jadziedzic]

PT typically warps more than non-PT KD, but there are always exceptions.

But why use wood at all? Use bricks.

 

[Sponsor]

 

[Jadnashua]

Yes, use concrete pavers or bricks on your slab. Regular wood works fine on a wooden subfloor, but no wood is great for a curb on a slab. Or, you can use one of the foam preformed curbs - most manufacturers make at least one style. A masonry curb takes a different technique to anchor your liner, if you aren't going to go with a surface membrane since you can't nail it low on the outside like you could if it were wood.

 

[hj]

ANY wood will "swell" it gets wet, and when it does that it will expand and crack the tile.