Durock and joint compoud
 

Remodeling bathroom just put up durock over tub and preparing to tile. Home depot salesman sad I could use joint compound on durock is this correct?

Um... No.

You want to use thinset with mesh tape for cement board, then some type of waterproofing membrane (maybe Redgard, I think that would be the brand that box stores carry) over the entire area.

If you put Durock farther than the tile would cover, then if it was not alot of area then maybe joint compound would work to cover it so it would match the existing wall surface.

Do not use joint compound under the tile.

That might be correct, depending on what he means by "joint compound."

The durock joints needed to be taped with a fiberglass mesh tape and coated with thin set. Get the bags of thinset and mix it yourself. Don't use the pails of pre-mixed.

Good point. If that's the case, a skim-coat is almost a must.

Sorry that you had to deal with stupid at HD, but that is what happens, when most of them have never done the work before. Most will just show up to collect a check and punch out at the end of the day. Only ones that I know of, that know their stuff, are those that work in the Paint department, and Lawn & Garden section, other than that, most are not worth anything to ask questions of.

I've actually been surprised by how many knowledgeable professionals I've run across at Home Depot - at least at the one I live near. This is an extremely tough economy, and I've run across professional plumbers, tilers and painters who are either laid off or in a slow season. They're definitely the exception rather than the rule, but there are a few out there.

I have to drive 25 miles away to get to our local HD. Only place that I have dealt with, that the workers actually know the department they are in, is the Menard's stores here, the Lowe's is far from having a whole lot of knowledge, and if you are lucky to find someone that knows what they are talking about, they are only there during the day or weekends, at night, it is usually just kids there.

You have no idea how badly I wish it was the Menards near my house instead of HD!

Only thing is, they do not have a wide selection of smart boxes, other than the single & double gang. I could spend all day in our newer Menard's. The one thing that I noticed last time I was in there, they had the 3/8" gypsum advert as 1/2", and the 1/2" as 5/8, and not much in durock, etc. like they had a year ago, when we were redoing our bath.