Check out some similar questions!

baradou · Jul 26, 2009, 05:40 PM

I am building a shower with a sloped mortar bed, unmodified thinset , kerdi membrane,unmodified thinset and tile (as per the Schluter guide). I am clear on this procedure but what I am trying to understand is how to go about waterproofing my curb.

I have piled 3 piece of 2*4 to build the curb and wanted to know if I have to screw in cement board on top and side, before applying the thinset and then the kerdi membrane or can I just lay thinset straight on the 2*4 and then kerdi?

baradou · Jul 27, 2009, 05:29 PM

Looks like I initially posted in wrong section in construction. Sorry about that.

Pleae chime in if you can help,ideas...

massplumber2008 · Jul 28, 2009, 04:24 AM

We'll see if this can be moved over to interior home improvement.. ..Bljack seems to know this system well... ;)

MARK

baradou · Jul 28, 2009, 08:02 AM

LOL, I believe Bljack already moved my post from Construction to Plumbing, are you saying it needs to be moved again to Interior home improvement.

massplumber2008 · Jul 28, 2009, 09:25 AM

Bljack can't move any posts... either can I. If it's still in plumbing later today, just repost it at interior home improvement. Bljack or others will find it.

Thanks...

MARK

Bljack · Jul 28, 2009, 02:56 PM

I am first going to let you all know that I am retiring from all message boards. I've been contacted by the widow of a foreign government official to help in collecting her funds he made that are currently held in the US. For my part, I will be getting a commission of 16 million dollars. I've sent my name and address ssn and bank account info for the wire transfer along with a valid credit card number to cover all related fees. I will think of you all after I purchase my own private island. ;)

Kerdi curb? Mud bed? What's going on here? Why didn't you just get the whole kit? Yeah, I know, custom size pans need to be mudded and then covered with Kerdi. Over a wood subfloor, you would stack the 2x4's, wrap in sheetrock, then cover with Kerdi and kerdi corners which come with the drain. If this shower is going into the basement you are doing, then over a slab, the best thing for curb construction is bricks or the kerdi preformed curb because wood doesn't like being in direct contact with a slab. If you used pressure treated, unless it is stamped KDAT (kiln dried after treatment) you can expect it to twist and potentially tear your curb apart as it dries out.

I had no idea you were doing a kerdi shower. With kerdi, you only need sheetrock, plain old regular sheetrock, no fancy green or blue or yellow kind either.

Now I'm off to figure out what else to buy with my millions!!

PS...

In answering you other post, the reason you cut your sandmix with added sand is to get a mixture that is less rich, making it pack tighter and work drier. You used the phrase "pour" but if you can pour it, it's too wet. You only want enough water to make it packable. You will need to maintain your perimeter gaps, just as you would have with self leveling cement but the mud is easier to place, pack and some lattice as a perimeter guide, sliding it down the wall as you go is all you need to do. Thinset as a bonding agent gives you a better bond, with a higher shear strength and the curing portland component of the thinset combines with the curing portland component of the mud.

60 lb bags? No problem. With my millions I have coming to me, I'll never need to carry one of those again.

By the way, Jaz hasn't been as active here, but he is an excellent tile mechanic and an excellent information resource as well. He's more computer savvy than I and he even has a web site where he goes over the steps of doing a Kerdi shower.

baradou · Jul 29, 2009, 03:32 AM

Congrats on your tresor find. $16M in commission heh! Good for you, better than winning the jackpot.
Thanks for the pointers and advice.
My project of raising the concrete floor is underway,I took some pictures as well but don't know if anyone would be interested to look at them nor do I know how to post pics in my thread.
On the curb construction, I had initially build it with 2*4, with the first piece on top of a strip of the pink foam (the one used for laying sill plate when building walls on concrete. I will remove and build with bricks based on your advice.

Yes, I could not find a Schluter pan for my 38"*38" shower, thus was looking at building a mortar bed and then kerdi the walls and the pan and the curb and also using a kerdi drain.

Bljack · Jul 29, 2009, 09:45 AM

Originally Posted by baradou

Congrats on your tresor find. $16M in commission heh! good for you, better than winning the jackpot.

With heavy heart I say that I've been duped. There are no millions coming my way.

... thanks for playing along.

Enjoy making your pan. :D

For those who find this thread while researching a project, get the 48" tray and cut it to size, it trims real nice and easy. ;)

baradou · Jul 29, 2009, 06:49 PM

Yes, I wish I could have used the 48" pan (would have been much easier) but my predicament is that my drain was roughed in when house was built 5 years ago with a drain centered 12" from each corner, don't want to break up concrete to relocate the drain :( .

Bljack, just a quick question , you mention since I will be using kerdi on the walls of the shower no need for anything special beside the regular drywall, I agree but given that I have a 6mm plastic vapor barrier over wool bat isolation, would condensation build up behind the tile and rot or I should not worry about it given that kerdi will stop this.

Bljack · Jul 29, 2009, 07:23 PM

Slice up the 6 mil plastic sheeting or remove it entirely. Kerdi is vapor proof and will take the place of the 6 mil plastic sheeting over the insulation. You don't want a vapor barrier sandwich.

What kind of thinset have you purchased?

baradou · Jul 30, 2009, 04:35 AM

The only unmodified thinset I can find a the local HD was PremiumPlus (standard thinset).
I can still return it if you suggest something else.

Now that I am done with raising the floor by 1" using the same number of bags you suggested (8 sand topping mix with 2 bags of sand), I am taking your words as the gospel ;).
Also now I know why they call this mud dry mix, easier to pack than the fat mud they talk about.

Now I noticed that the basement wall have insulation and the 6 mil sheating covering only 3/4 of the wall, with the last 1/4 from the floor left un-isolated,(maybe the building code states that this is below the freezing line and no isolation is needed, don't know, but I now that the basement is never cold nor damp) all that I see is the black tar paint, they paint inside the foudation walls. I believe they painted it on the outside walls as well. Do you still think I need to remove the vapor barrier covering the 3/4 of the wall or the vapor will evaporate through this big 2' opening (wall being 8')

Bljack · Jul 30, 2009, 03:37 PM

Premium plus will be fine to use, I just wanted to make sure you wouldn't be using Custom Blend. Not a very good dryset. It's borderline being just sand.

Do you still think I need to remove the vapor barrier

Is there a reason you don't want to slice up the poly sheeting? Some emotional attachment? Lack of a sharp utility knife blade? I'll send one out to you. Just pay the postage (16 million US dollars :cool:).

Sometimes odd stuff comes up where you really need to ask the manufacturer. Seems to me that if the bottom section had no insulation, there would be some part where air could carry vapor away, especially if it was framed with metal studs with all those pre-existing cutouts for pipes and wiring, especially if you placed vent covers over a couple cutouts in the wall to ensure air flow.

baradou · Jul 30, 2009, 04:56 PM

If you had asked 16M$ other that US currency, I would have thought about it, like some currency where 10,000 of something is worth like a penny :) .
:p,no real attachment , but another great idea you have given me with the vent covers over couple cutouts, Tks.

The more I think about removing the 2*4 for the curb and replace with bricks, I thought of just building the curb , 2 sides of 38" length and 5" high with the same dry mud (same as what I used to build the 1" thick floor) with couple of metal bar for reinforcement, bad or good idea?

Non related question, but in your avatar, I am impressed to see your kid I assume, laying tiles. I have not personnaly done that yet, will be my next project once I am done with putting the gyproc (ceiling and wall).

Bljack · Jul 31, 2009, 05:23 AM

Originally Posted by baradou

Non related question, but in your avatar, I am impressed to see your kid I assume, laying tiles.

Not my kid, there was a customer who couldn't pay their final draw. Took their kid on as a helper for 3 weeks to work off mommy and daddy's new dream bathroom.

No, that's really my 11 year old, 9 at the time the picture was taken. He's always shown an interest and along came a "bring your child to work day", and he opted to come with me. It was by far, my favorite working day ever. He's come along a few more times, He's a mad man ripping up vinyl, works ahead of me filling Ditra waffes and runs to the saw to make cuts. He hates cleaning out buckets.

Oh, to answer your question about the curb, as long as you used the sill gasket like you said, and you didn't use pressure treated lumber, just leave it and wrap it with scraps of your sheetrock.

baradou · Jul 31, 2009, 11:01 AM

Sold, sheetrock wrapping the curb it is.
I knew you had a heart(seeing me take out the 2*4 ;)

baradou · Aug 6, 2009, 08:37 AM

It is been 8 days since I got done with the resurfacing/raising the floor by 1". Given that it took me 2 days to apply the mud on the 72 sqft surface (could not finished it in one day). Today I noticed that there is a crack btw the section where the previous day mud job meets with the next day. Also if I tap lightly on that section, I can hear a hollow sound.

Don't know if I need to break the whole thing or just the section where they meet, break it down to reach the floor under that 1" and re-mud.

Bljack to the rescue:)