Is There A Reason People Don't Grout Cardboard?

[Spydr]

does it soak into the cardboard causing cracks or something?

 

[BadCon]

Cardboard won't hold up when wet...so whatever shape you started with is probably not going to be the shape you end up with. Also cardboard is harder to shape then foam, and is much heavier for its total strength.

 

[Spydr]

ok. just wondering. also, does it have to be polystyrene foam? what about that crappy foam at micheals?

 

[kjinxx2]

I find the green floral foam that michael's sells works better but is more expensive. The reason that cardboard doesn't work is because the foam is what holds the grout together, it acts as a skeleton.

 

[triumphtt]

go get the pink or blue stuff at lowes or home depot its like $8 for a 4'x8' sheet the problem is getting it home