protruding screwheads on hardibacker

[Glenn Pope]

After putting down the hardibacker, the screwheads protrude a little. They did not countersink. Does that matter, or do I need to countersink them or just hit them with a hammer to set them?
Also, we have greenboard on the shower walls, and we are kind of ready to start the shower pan. Do we put plastic or tar paper down on the subfloor and on the walls now before anything else? Thanks.

[Bud Cline]

Hardi huh???!!!

[Mike Berry]

Hi Glenn,

Sounds like Bud is amused...I mean confused

I think he is looking for more info on what you're doing before he can help....and he CAN help. The pros around here are REALLY helpful!! But...they also like to have some fun

Being a tiling "newbie" I understand how hard it was at trying to explain to the "pros" what I was doing.

My two-cents, but DEFINITELY wait for the pros before you go any farther:

For starters, I don't think you EVER hammer screws into cement backer board (hardibacker). What's a "little bit" sticking out? Seems to me that they need to be flush, not countersunk. Is the hardibacker on the floor?

It sounds like you'll need to understand the "anatomy" of a shower floor and shower pan liner. John Bridges, or one of the other pros, will fill you in on that. Also, I don't think anyone here will recommend greenboard as a backer on shower walls. I'm sure they will tell you to use CBU's (cement backerboard) or mortar.

Good Luck, and stayed tuned here....there's lots of help here.

Mike

Glenn

Did you use the kind of screws made for cement board? These screws have little thingys under the head that help cut into the cbu and enable them to be driven flush.

You want the screws to be flush, especially if using 4 1/4's or 6 inch tile that sits very close to the substrate.

[John Bridge]

Hi Glenn,

Driving the screws with a hammer is not a good thing. The screw will not be tightly drawn up against the material then. If it's a floor and the tiles are large, you will probably be able to sort of glance over the screws. If you come to one that hits on a ridge of the tile or is otherwise in the way, bang it in and place another along side of it. I'm sounding a lot like an experience hand in backer board, which I'm not.

You can use green board in the shower if you place a vapor barrier AND CBU over it. The sheetrock must be cut off at the bottom to allow room for the shower pan liner to fit against the solid blocking I know you've installed.

Go to the "Liberry" and find the articles we've posted on shower pan installation. Harry's got one there, and there's one by Michael Byrne.

[Tom]

Hi-Lo screws that are made for cement board are difficult to use with the harder cellulose/cement hardbacker. You can use galvanized roofing nails, or coated deck screws work well and are easy to drive flush while being as strong and no more expensive than hi-lo screws. Using square drive screws makes it even easier. Don't use deck screws in cement boards like durock or wonderboard.

[Glenn Pope]

the hardibacker is on the floor. That is where I have trouble with the heads not being flush. They are the correct screws for the hardi, but they do not have nibs to countersink themselves. I guess I could replace them with something else. Their large dia. head seems to be the only thing that distinguishes them from sheetrock screws. They countersunk fine in Durock, but I choose to use Hardi because it is easier to cut.


The shower is going to be mudded. That is a ways off, still. I will put a moisture barrier up first. Thanks

[Glenn Pope]

The sheetrock is cut off for the pan. The sheetrocker knows more than I do. Thanks

[John Bridge]

hey, some sheetrockers are pretty smart. I was a sheetrocker for a year during my apprenticeship days.

[sgs]

I was just about ready to put some tile in and I've got a number of deck screws in the wonderboard, in fact I've got all sorts of different flavors up there. Should I replace them with wonderboard screws, now that I finally found them. The screws are easy to get too but is it really necessary.

[davem]

Hi sgs, I'm just a beginner, but I've read here that "bugle head" screws have a tendency to pull through the cement board (cbu). I would wait for pro advice before you hang your tile.

[John Bridge]

I'm no more of an expert on this subject than Dave is (no offense, Dave ). I would nail hot dipped galvanized roofing nails alongside the screws and then go for it.

[Bud Cline]

Now you guys are beginning to see why I eliminate the vapor barrier and trade it for adhesive. I want those cement boards glued 'fast' to the studs. Someday I'll win that arguement. The TCA is just plane wrong on this one.