Can stucco be placed directly on Hardibacker board ?

Question

Building a barbecue island and using Hardibacker board. I know this will take Thin Set but am not sure if Stucco can adhere directly to it. No one will give me a direct answer. Hardibacker board company says to consult the stucco manufacutuer.

I don't want to hassle with a metal mesh if I don't have to. My assumption is if I use concrete adhesive and then stucco, it should be fine but want answers from people that know or have done this.

Additional Details

I plan to scratch, brown and texture coat. Also the Hardibacker board is attached to steel studs. I plan to tile the top which of course I will be using thin set but plan to stucco the sides.

As for the heat of the barbecue, I don't think that will be a problem since I see this method of contsruction on commerically sold barbecues.

As for the adhesive there are commerical adhesive that you apply on concrete which helps adheres aditional concrete or stucco. I was thinking of this since hardibacker board is made of cement.

Answer 1

Best Answer - Chosen by Voters

do a thin skim coat of thinset, and while it's still fresh apply stucco, it will bond. it will bond as is to the hardibacker, but because of hardibacker construction it will wick out the moisture too fast on the stucco, the skim coats give the stucco a better bond, and by stucco are you referring to the scratch, brown and then color coat, or just the color coat ( texture coat )

Answer 2

Have you determined whether or not the FINISH will endure any levels of heat from the BBQ; above normal FULL SUN?

Certainly concrete backer board is texured enough; though I'm not sure why you suggest thin set?

In your statement about concrete adhesive I'm confused as well. Are you intending to GLUE the backer board to block? Then stucco over?

If you assume the block will get hot; forget about adhesives. If you know that the block is double walled; or this is a Decorative touch that won't be in close proximety to any heat; use Fiber glass based stucco.

Steven Wolf

Source(s):

45 plus years as a contractor