Ceramic Tile Advice Forums - John Bridge Ceramic Tile

Ceramic Tile Advice Forums - John Bridge Ceramic Tile (https://www.johnbridge.com/vbulletin/index.php)
-   Tile Forum/Advice Board (https://www.johnbridge.com/vbulletin/forumdisplay.php?f=1)
-   -   Help with tiling bath in new construction (https://www.johnbridge.com/vbulletin/showthread.php?t=6190)

lexrn 05-11-2003 08:11 PM

Help with tiling bath in new construction
We are probably about 1 1/2 months away from this but I thought I would start gathering info from this most excellent forum.
I have Michael Byrne's "Setting Tile" book and I've watched 1 1/2 of his videos but I still seem to have lots of questions because most of the information is geared to remodels.
Here is the job: the bathroom will be approx. 11 x 11 with a whirlpool tub and separate, doorless shower 42 x 60. The shower will have a ready-made recessed receptor, either Florestone or similar. For this post I'll limit my questions to the floor: must the contractor lay a sub-floor with CBU on top of it or can we use CBU alone? If a subfloor is necessary, can it be osb or should it be plywood? What thickness should it be? What thickness CBU?

bctile601 05-11-2003 08:29 PM

hi lex
yes the general contractor will run his subfloor throughout the house, it's usually 3/4" advantech around here. some builders use plywood. either is acceptable.
from there a tile underlayment must be installed, that may be ditra, or cbu. then your tile is installed on top of that.
since the subflooring is 3/4" the thickness cbu needed would be 1/2" please post any furthere questions

lexrn 05-11-2003 09:12 PM

Thanks for clearing that up so fast! Okay, 1/2" cbu over 3/4" osb and the cbu is placed in thinset mortar fastened with anti-corrosive screws every 6" to 8"? Leave 1/4" gap between boards then tape and apply thinset? Okay, now for the interesting part: I want to use a tile warming system, probably Watts Suntouch. After the woven mat is secured to the cbu would I snap layout lines on it then apply thinset and start laying tiles?

bctile601 05-11-2003 09:56 PM

that's a touchy install lex

yes mfr. says you can install directly over the heater mat, however, i like to flash / patch over mat first, then tile. a good self leveler will work great. i think they use 14 gauge wires in those mats, and then they have special insulation caotings too, so they are quite thick, too thick to just trowel and drop tiles like they show in brochures and videos, they might get 30% coverage effectively. v poor approach
also there is an accessory available with the suntouch, i think it's called " loud mouth " ... a device that is hooked up to mat during the tile installation, so that if you break continuity anywhere, the thing starts singing like a car alarm. will prevent you from finishing tile and finding out heater don't work. HIGHLY reccommended. be sure to read and understand mfr's instructions with both the mat, and self leveler
please post any further questions lex

lexrn 05-11-2003 10:42 PM

Uh oh...what is flash / patch?

Art in Stone 05-11-2003 11:50 PM

I think a really got alternative, using a great product, is Ditra. It will probably be a better Idea too.

How do you Flash Patch the heating system. Do you do it like on a concrete slab? Prime/ rough coat/ smooth coat? Or flash Patch like drywall?

bctile601 05-12-2003 05:46 AM

i believe you could use ditra, but some of the heater mfr's instructions say to " channel out " for a sensor lead or something. in that case you could not use the ditra under the mat.
the flash / patch should not be intimidating lex, is fairly simple. leveler is mixed to a fairly fluid consistency, then poured and spread around, is so " fluid " it will find it's own level, covering wires, so you will have a smooth, unobstructed surface to set tile.
you must however tape cbu joints prior to heater installation, and if leveler requires a primer coat, that also would be done prior to heater install

tileguytodd 05-12-2003 06:40 AM

For the suntouch or Warmly yours heating system i would reccomend using a self leveling cement rather than CBU.
I guess i would like to Back up a little bit and find out a little more information such as joist type and spacing and longest span of unnsupported run.After that we can determine if 1 layer of plywood or advantech is enough to pour over.To do a heated floor install in this manner once the subfloor issue is straight,heres is the order
#1 2.5 wire lathe
#3-Heating mat
#4-5/8" Self Leveling Cement Pour
I sent john a few pictures of this type install a while back.in that particular case the homeowner installed the matt before the lathe.This can be done,however you need to be extremely careful you do not wreck the matt when stapling the lathe. Lets see if john will post thise pics, I dont have any copies!!

lexrn 05-12-2003 09:45 AM

The builder will be here tomorrow. I'll ask him about joist spacing, etc. The Suntouch website shows the mat being stapled, taped or hot-glued to the backerboard. (They talk about using slc if the floor needs to be strengthened.) They recommend a 3/8" x 1/4" trowel to apply a latex or epoxy modified thinset. Reading about it is one thing...

lexrn 05-13-2003 07:45 PM

Regarding the floor, the plans specify 9 1/2" BCI 16"oc with 7/8" Edge Gold on top. I would like to have a doorless shower, about 36 x 60. I haven't decided how to do the shower floor yet but I'm wondering whether the floor outside of the shower would need to be more waterproof than using CBU...and yes, some of the wiring needs to go in a channel so that rules out Ditra?

bbcamp 05-13-2003 09:11 PM

Hi, Lex! Your floor is good to go if the joist span (between supports) is less than 15'-5", assuming the top and bottom flanges are 1 1/2" wide. If they are 1 3/4" wide, then they are good for 16'-1".

OK Todd, he's all yours! :D

bctile601 05-13-2003 09:37 PM

ditra ruled out? ... im not really sure but i think so yes ... but i put a call in and ask for you. probably post tomorrow night

lexrn 05-13-2003 10:28 PM

From the SunTouch site: "Power Lead Installation: The power lead is thicker than the SunTouch mat. If thinsetting over backer board or slab, chisel or saw a groove to recess the power lead to the level of the SunTouch. Or end the power lead at the floor and run just the heating wire to the beginning of the mat." They also say the mat can be installed over an isolation membrane. So, doesn't sound like a problem although I can't exactly visualize the thinset going over the mat very easily. Well, I have time and I am reading the Michael Byrne book and I'm going to order John's book too. Oh, and from reading lots of other threads in this forum and my own experience, I can see how helpful all you pros are. Thanks for your time and advice...

doitright 05-13-2003 10:54 PM

Hi Lex,

I just completed a Suntouch install over 1/2" Durock. Snaping chalk lines, seeing them is almost impossible. However, I did have a successful install directly over the mats.

1st and foremost, invest in the Loudmouth. A fellow contractor had to tear out several tiles for repair, because he cut a lead (it is repairable), and didn't know until after the floor was installed.

If after installing the mats and leads, I recommend flat troweling the thinset the day before. Then you can chalk your layout lines. A self leveler will work, but it will still consume a lot of material to cover the wires. With a good mix with the thinset, you can still achieve the proper coverage for a good tile bond.

Aside from hydronics, the Suntouch system is one of my favorites! :)

lexrn 05-13-2003 11:06 PM

Hi John...yeah, I will invest in a LoudMouth for sure. Now, let me try to understand what you mean by flat troweling the thinset the day before - do you completely cover the mat with the thinset at this point? And, it's a flat coat? Then, the next day, lay the chalk lines over this and apply more thinset and tile? Do you do it this way because the chalk lines are so hard to see on the mat?
My other dilemna is whether or not I need to use a waterproof membrane on the floor because the shower will be doorless and I don't know how wet it could get. Of course, if I do the shower first I guess I would find out!

All times are GMT -6. The time now is 08:41 AM.

Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Copyright 2018 John Bridge & Associates, LLC