View Full Version : Schluter's Line Drain - A closer look at the new linear shower drain from Schluter
05-12-2011, 08:40 AM
Here is a look at the new Schluter Linear Drain.
This picture I took last week (March 2013).
The drain appears to be forming some rust inside the drain base.
I managed to clean off this rust with a 3M polishing pad.
For more details on the Kerdi Line drain you can see pictures here (http://no-curb.blogspot.ca/2011/02/schluters-new-line-drain-or-gutter.html) - http://no-curb.blogspot.ca/2011/02/schluters-new-line-drain-or-gutter.html
I email Schluter's tech support and asked how this could be happening and was sent an email that talked about cleaners and how stainless steel is rust resistant but not rust proof - or something along those lines.
My gut tells me that the installer scratched the drain base or the plumber left metal (non stainless) filings behind when he installed the rest of the shower fixtures.
05-12-2011, 06:31 PM
Problem with any waterproof membrane and essentially an impervious porcelain tile (glazed ceramic can still be a problem, but not as big) is that a modified thinset needs to both dry and to cure. It only has the grout lines to dry from, so it's similar to the effect of using mastic and large tile...it takes excessive amounts of time to be stable. An unmodified thinset doesn't have these problems. The difference in 'stickiness' between a premium unmodified and a modified in total strength isn't all that much, relative to the scheme of things, as either is more than enough in most circumstances. Schluter has given permission to use fast setting modifieds in special circumstances, but these are best left to pros verses the more typical slower DIY'er.
05-12-2011, 07:55 PM
Thanks for the info Jim. I have heard this many times before and understand that the specification from Schluter revolves around blanketing all installs and much of their stand is based on commercial work in colder climates.
No shower should be set and then grouted the same day. I like to see them cure out a week before grout hits the tile.
I have spoken with both of the Canadian top techs at Schluter within the past six months and they both said Grani Rapid from Mapei. Both said then I loose my warranty. If you get special permission. If the local rep signs off on it. If you can get him to look let along even call back then maybe, just maybe you will get permission.
I have been looking for anyone who has a written OK and have found no one.
They don't build swimming pools with Kerdi and Non-Modified thinset. They do use Hydro Ban and Aqua Defense. Why?
05-13-2011, 09:09 AM
I think that it's just that the company is conservative...they don't want a failure, and they are sure it works with an unmodified. If a modified is used, and it hasn't dried properly, you can compromise the bond - I don't care whose membrane you use - moisture doesn't go through it, and neither does it go through the tile (at least very fast), and it WILL take excessive time to properly bond. If the tile is disturbed before that happens, you can have a bonding failure. A modified between impervious surfaces is almost like a mastic...on larger tile, it can take weeks to dry out and approach what an unmodified achieves in a day. How many people are going to stay off the surface for that long? Yes, the rapid set stuff (at least the cement part) cures rapidly, but if properly mixed, those sand and cement particles are coated with the modifiers, which don't reach full strength until they dry.
While many people may know you should remix a modified after slaking, most (IMHO) do not know why. The modifiers must hydrate so they can flow properly to coat the sand and cement particles. That happens, not in the first mixing, but after slaking and during the re-mix - they absorb the moisture and become stickier and can flow while remixing. If the second mixing is done too soon or ommitted, the thinset will be considerably less strong and have a very different texture from when the instructions are adhered to. Some people tend to add more water than specified trying to get the texture what they want. This weakens the mix. If the proper mixing, slaking, and re-mixing times are adhered to with a proper paddle and speeds, they'd most often find the prescribed water content is right on. This info comes from manufacturer's reps as received at a class at the TCNA school. Old habits die hard, and many people (pros included) do NOT mix their mortars per the instructions. They'd be surprised at the differences if they did.
It is a tribute to the mortar manufacturers that ANY modified thinset works when sandwiched between a waterproof membrane and a highly impervious tile.
05-13-2011, 10:24 AM
Jim this is a big debate online.
There is no solid research to defend or disprove anyone's stand. I was told years ago that there was massive failures looming but have seen nor heard any proof of this here in Vancouver.
I have a testing plan under way.
Clear Plastic Panels.
Drytex set over top with white mesh.
Skim coat white non-modified thin set.
Set mock up with Kerdi-Non Modified thinset.
Document dry time from drytex goes from pink to white.
monitor drytex over a period of a week.
Same test using Nobel TS
Same test using modified Thin set.
Same test using Rapid Setting Thin Set.
I have purchased all the material to do this private testing and just need time to clean off the shop table and get the right blade on my table saw to cut the plastic.
I'll post a play by play.
I will repeat this testing in the winter and see the changes when temperature is a factor.
I think the results will be interesting to watch and document.
06-14-2011, 09:57 AM
So the Kerdi Drain is hot off the press. I have picked one up and will take some detailed measurements to aid in upcoming projects.
Got to run to work right now but should have some new pictures and calculations ready by tonight.
06-15-2011, 09:19 AM
Some pictures of a Kerdi Line drain installation.
Here you can see that the top grill (with wing tabs) is installed a little off center. I emailed Schluter to confirm this last week and am still waiting for a response. I also asked if the Aqua Defence could be removed from the sides of the drain safely since the home owner does not like the look. This is not our installation but we where called out to take a peak.
The tile installation looks great. It would have been nice to see a better job around the grill and less chaulking or silicone used to finish this trim. Not sure why all the silicone or chaulk was left inside the drain base.
06-15-2011, 09:21 AM
06-15-2011, 09:23 AM
06-15-2011, 09:28 AM
The Installation Instructions;
06-16-2011, 07:36 AM
I have viewed the Kerdi Linear Drain installation video and the manual that comes with my Kerdi Linear Drain.
I am totally confused as to why Schluter wants me to cut the kerdi at the drain corners. This makes no sense. You can see the process on the Video here at http://www.kerdi-line.com/ and above in the pictures.
In every Kerdi manual and installation advice you are told about a 2" overlap in the seams yet with the Kerdi Linear drain it seems 5/8" is fine.
I feel that a tucked corner or the use of Kerdi Fix would be a much safer installation.
I'm going to look more into this advise as I fear these two corners to be a weak link in the waterproofing steps by Schluter and their new linear drain.
I called Schluter Systems Tech Support in the USA just now and spoke to Brian. I asked Brian what type of thinset they specify for the installation of the tapered foam base to the OSB plywood and was told to no surprise to use Non-modified thinset and a 1/4" x 3/8" trowel. I asked Brian about the cutting of the Kerdi and only having about 5/8" of overlap and was told that in this type of installation it would be fine and that 2" overlap is "Overkill" - his words not mine.
I just placed a call to Schluter System Canada and am waiting for Courtney to call me back. I would like to get her read on this.
I'll let you know what she says.
06-16-2011, 01:40 PM
Since any water on that edge will drop into the drain and not puddle or pool there, a token seal provided by the narrow band should be more than enough. The same can't be said for the junctions of walls where tile and tile could meet. I'm assuming that the metal has a slight angle to it towards the drain. Since the metal won't wick and the Kerdi is hydrophobic, that band should be plenty. My opinion only.
06-16-2011, 11:37 PM
Jim I do not think Kerdi is Hydrophobic.
06-30-2011, 08:07 AM
Standing by for news updates from Schluter.
I'll post my questions on their facebook page as well.
07-15-2011, 08:47 AM
If your going to install this linear drain from Schluter make sure your installer has a valid Schluter Installer Card. This past two weeks I have heard from three inspectors/builders that this is absolutely required by city hall here in Vancouver and the surrounding area.
We have been called out to look at two failed linear drain installs in as many weeks. Installing these linear drains that get set with thin-set is a little different that dropping in a compression drain.
Ideally your Kerdi Line drain would be set by a card carrying Kerdi Installer who has taken a line drain course, or who at the very least is ticketed by Schluter to install Kerdi and the plumber would hook it up from below. It would be rare to find a plumber who has in fact a Kerdi Installer Card.
The Kerdi Line drain is set onto the styrofoam disc with just non-modified thin-set so you should caution the plumber to not press up to hard on the connection point with the 2" no-hub fitting if the drain is freshly set and the surround tile not set.
I prefer to do this process with the plumber to insure that no stress happens to the drain assembly durning installs. From above I can double check positions and insure that the plumbing connection does not cause the linear drain to twist or go out of angle.
The drain should not hold the weight of the piping and strap tie should be used for this. We like to wrap the waste pipe very securely so one day when the snake comes out this length of pipe is well supported.