Durock seems very thick?

elementx440 · 05-03-2007, 09:57 PM

So I got some durock board for my small bathroom remodel. I plan to tile the floor and walls all the way up, so should I just box the entire room in the stuff?

I'm just worried about the thickness of the durock, especially on the floor combined with tile/grout thickness.... It seems like you'll have to step down out of the bathroom???

Am I missing something or what?

jproffer · 05-03-2007, 09:59 PM

You can get 1/2" or 1/4" if you look hard enough.

Yes, put it wherever you want tile.

crecore · 05-03-2007, 10:17 PM

a lot of time, effort, planning and money on underlayment goes in to making floorplans flow from room to room with open floor plans and varying flooring types without "steps."

http://www.schluter.com/ systems also makes a real nice line of profiles... click on products/ tile floor for ideas. You can tile right on wood with the right products but you need enough thickness to prevent flexing and cracking...1-1/4" minimum comes to mind, dont quote me on that. So this creates the same problem.

elementx440 · 05-03-2007, 10:36 PM

Quote:

Originally Posted by crecore

a lot of time, effort, planning and money on underlayment goes in to making floorplans flow from room to room with open floor plans and varying flooring types without "steps."

Alright so there just isn't much you can do in an existing house, huh?

I guess I'll just use this on the door instead....

Am I right about "boxing" the entire room in?
Is the durock absolutely needed on the floor? My kitchen had existing tile right on the subfloor (well on 1/4 louan), and it never showed any damage/cracks. That would be one way to avoid a "step"

jproffer · 05-03-2007, 11:18 PM

Quote:

You can tile right on wood with the right products

Such as.....??? If you're talking about modified thinset, you're mis-informed. It IS true that modified thinset will work to set the tiles directly onto wood..BUT, you don't want the tiles to be set directly onto the wood.

Tile expands and contracts at a (much) different rate than wood. You need something to "decouple" the tile from the wood or this movement could cause cracks. The products that do this are: durock* or ditra*.

Quote:

That would be one way to avoid a "step"

So you're saying the lack of a 1/4" sheet of rock would leave the floors level? So worst case, we're talking about a 1/4" step if you went ahead and used the rock? Get an offset threshold and the only person that will notice is you.

* The use of product names is not intended to promote these brands of products. They were being used as "generic" words. I call ANY rigid CBU, durock...and ANY membrane type product, ditra.

BTW the fact that your kitchen floor has lasted however long it's lasted is the exception, not the rule. In fact, you have a double wammy. 1/4" luan is NOT suitable for use with ceramic tile, even if it has durock over it. I'm glad that it's lasted for you, and hope it will last forever, but I would truly be surprised if it does.

elementx440 · 05-03-2007, 11:35 PM

Well I'm anticipating 1/2" or 5/8" for the cement board (I forget which I have right now), maybe another 1/2 for grout and tile? You're talking close to an inch difference in height, as of now it's about level...

Maybe I can use that rubber membrane stuff on the floor...

send_it_all · 05-04-2007, 01:11 AM

Inside the shower where there would be direct water spraying on the tiled surface, use the 1/2" durock or hardi backer over a vapor barrier...(15 lb. roofing felt) stapled to your studs with about 8" overlap.
Outside the shower, where there wont be direct water contact, you could tile directly over greenboard drywall. On the floors, I would go with 1/4" hardi backer to help with the flooring transitions. Everywhere you use the cement board, leave gaps between the boards of 1/16th to 1/8th of an inch and use the specified (alkali resistant) mesh tape to tape all of the seams between boards. Then trowel a layer of thinset over the seams as you would drywall. The pro tile guys could probably add something to this. I am not a pro tile guy, but I have read up on this and tiled several bathrooms with these methods.

**AtlanticWBConst.** · 05-04-2007, 07:09 AM

Quote:

Originally Posted by send_it_all

Inside the shower where there would be direct water spraying on the tiled surface, use the 1/2" durock or hardi backer over a vapor barrier...(15 lb. roofing felt) stapled to your studs with about 8" overlap.
Outside the shower, where there wont be direct water contact, you could tile directly over greenboard drywall. On the floors, I would go with 1/4" hardi backer to help with the flooring transitions. Everywhere you use the cement board, leave gaps between the boards of 1/16th to 1/8th of an inch and use the specified (alkali resistant) mesh tape to tape all of the seams between boards. Then trowel a layer of thinset over the seams as you would drywall. The pro tile guys could probably add something to this. I am not a pro tile guy, but I have read up on this and tiled several bathrooms with these methods.

Very well said. Only other point to add is: If you have any areas of the cement board that border something like a fiberglass shower pan, use silicone based caulking to seal the seam.
(I think someone already mentioned using thinset for attaching the 1/4" cement board onto the floor areas.)

Last, use appropriate fasteners to attach the cement board.

link:

http://lawn-garden.gillroys.com/Hard...s-s276626.html

**AtlanticWBConst.** · 05-04-2007, 07:14 AM

BTW -

The exact term for it is: "Cementious backer board".

As mentioned, 'Durock' is a name brand...... sort of like the way all reciprocating saws are referred to as 'sawzalls'....

Also, the DITRA membrane is a great product .....

zel · 05-04-2007, 07:29 AM

They also make a whole bunch of threashholds that should transition into the "lower" room too.

elementx440 · 05-04-2007, 05:44 PM

I'm installing a jacuzzi fiberglass tub, with the matching walls, would you still put the roofing-paper under it?

send_it_all · 05-04-2007, 05:47 PM

Quote:

Originally Posted by elementx440

I'm installing a jacuzzi fiberglass tub, with the matching walls, would you still put the roofing-paper under it?

I wouldnt think it would be necessary. In fact, that set-up should be able to go right over drywall. You may want a second opinion.

jproffer · 05-04-2007, 06:28 PM

Quote:

Well I'm anticipating 1/2" or 5/8" for the cement board

There's no such thing as 5/8" CBUs. Take back the 1/2" that you have and get 1/4". IMO the only good reason to use 1/2" versus 1/4" would be if a situation was the reverse of yours...if someone needed to ADD another 1/4" to meet another floor. Beyond that, they both serve the same purpose and do the job equally well.

Quote:

maybe another 1/2 for grout and tile

Most ceramic tile is 1/4" thick. The thinset will be about 1/8" after the tile pushes it down.

So with all this, you're about 3/8" over what you would be if you used no backer at all.

**AtlanticWBConst.** · 05-04-2007, 07:49 PM

Quote:

Originally Posted by send_it_all

I wouldnt think it would be necessary. In fact, that set-up should be able to go right over drywall. You may want a second opinion.

It's actually advised by one of the cement board manufactures. I stumbled across it myself on a PDF instruction for their product. FWIW -It does make sense to me....

**AtlanticWBConst.** · 05-04-2007, 08:08 PM

Regarding the Moisture barrier behind the cement board: I think it's an 'advised' point, but not a 'rule'.

'Durock' brand cement board Installation guide:

http://www.cgcinc.com/pdf/install/EDR_00D6.pdf

'Perma base' brand cement board installation information:

Do I need a vapor barrier behind PermaBase?
PermaBase is not a vapor barrier and an additional barrier is not required in most conditions. In areas such as indoor pools and saunas, a vapor barrier is recommended. (From the link below)

http://www.nationalgypsum.com/resour...mabase.aspx#12

I have not been able to find the manufacture's link or PDF that I read a while ago regarding the moisture barrier point. But, here is a link where it is mentioned again:

http://www.johnbridge.com/vbulletin/...php/t-563.html