shower wall membrane?

[rayzor1234]

hi, i started my shower project and did a bunch of reading, none of the articles i read mentioned a water barrier. then i read that i needed to place a membrane over the studs and then put up the backerboard. to late. i already put up the backer and mudded and leveled. is there anything i can do after the fact? like a paint or somthing i can coat the backerboard with before i lay the tile?

[Mike2]

It's not too late to apply a liquid waterproof membrane like Custom's RedGard. You can read more about it here on Custom's website . Typically it can be found in the tile section of any Home Depot store, near the thin-set mortars and grout. Expect to pay $35 or so a gallon.