Poor Man's Kerdi Fix

[Loui]

I was just quoting CX on the first page. He stated silicone was an acceptable kerdi fix replacement according to schluter.

[cx]

Not at all sure I said that on the first page, but Herr Schluter has said the 100 percent silicone is an acceptable substitute for KerdiFix. Don't know where we've seen that in writing, but I doubt I'd be advertising if I'd not seen it at least once. Been wrong before, though.

I'd much rather use KerdiFix, but I've personally tested the 100 percent silicone with a number of different substrates and it sticks Kerdi to them quite well. Stick Kerdi to Kerdi and you're gonna lose the fleece on at least one side if you pull it apart after it's cured.

My opinion; worth price charged.

[Tiger Mountain Tile Inc]

Now that I'm thinking about it you don't really use K-fix in that many places with the Kerdi membrane. My first thoughts were using silicone for joining foam boards together like Wedi. But I could see using silicone for tub flanges and that sort of thing.

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I've been tinkering with GoBoard a bit around bathtubs. I guess they are coming out with a proprietary sealant but this is the sealant (amazon.com) that my local distributor carries. I would think it work for Kerdi board and whatever.

Amazon says $10 but I paid less than that. It smells and takes longer to dry but it works well.

[Orangeyougladtobekerdi]

I see this topic has been gone over more then once but I was hoping for some opinions on possible substitutes as the Real thing is not practical here in Canada.

I checked my local Lowes, Rona, Home Depot no one carries this stuff Amazon.ca carries it for around $27+ $10 shipping, as I am doing a Kerdi membrane (actually Prova) kit with the pan and curb all I want is to do a few touch ups (The very top of the corner patches did not stay, I would like to use some on the curb and will also be building a niche without buying the $120 prefab foam board one) and $40 + shipping time for a few squeezes on the caulk gun is too much. I have looked and similar sealants made by Wedi, Durock, Nobel etc are not available here even on amazon. There is one by PROVAfor $20 but it says "Siliconized" which my research says is acrylic like what custom makes and is not recommended on this site ( and I can get kwik seal ultra from DAP for $6 and is also "Siliconized"

So far recommended alternatives are Silicone which will stick well to the membrane but nothing will stick to it, and Siliflex which is PU so is not recommend and may break down over time but has been used successfully by many members here.

Google tells me that what makes Kerdi Flex superior and pricey is it is a MS Polymer sealant (to be more exact the Kerdi Fix Spec sheet lists the base as Silyl-Modified Polymer- SMP, the Schluter websites calls it silane-modified polymer base, google tells me all the above are "MS Polymers")

This being the case I have found some possible alternatives I was hoping you all might weight in on:

LePage PL Heavy Duty Sealant $10/tube:

TDS says base is Silane Modified Polymer sounds, paintable 1 hour, cures in 24 ... sounds familiar but then says for best results not to use for immersed joints or under shower door tracks ... not building confidence

QUIKRETE® Advanced Polymer Non-Sag Sealant (No. 8660-11) ~$8/tube:

TDS says one-component, permanently flexible, multipurpose, solvent & isocyanate-free, tack free in an hour cures in 24, printable.... sounds familiar also states

QUIKRETE® Advanced Polymer Non-Sag Sealant may be used for:
Sealing & Waterproofing horizontal or vertical control joints or
expansion joints in sidewalks, driveways, industrial floors, parking
decks

Promising but I cant find anything that says what the Polymer actually is .. the elongation to break is higher then Kerdi Fix so not 100% this is the same goop


Now the Front runner

XCEL IGA $12/tube free shipping on amazon:

TDS and MDS eaisly found on the website along with a demo of them gluing 3 pavers together underwater and lifting them out...

XCEL IGA is a high strength, high viscosity, one-component elastic adhesive
for indoor and outdoor applications based on MS Polymer. Specially designed
for fast and non-rigid structural bonding in construction, metal industry, auto,
marine, etc., with excellent adhesion to most substrates. Completely weather
resistant, odourless and does not contain solvents, silicones or isocyanates.

Again sounds familiar and better yet even the elongation and density are a close match

aw material basis: MS Polymer
Consistency: Non-slump paste
Specific gravity: approx. 1.55 g/ml
Skin forming time: 5 – 10 minutes (at 23ºC; 50% R.H.)
Curing rate: 2-3 mm/24 hr
Resistance to flow (ISO 7390): approx. 0 mm
Consumption: approx. 50 ml/ linear meter (nozzle diameter: 8mm)
Application temperature: Between 5ºC to 40 ºC
Properties of the cured product: (After one week at 23ºC and 50% R.H.)
Service temperature: -40ºC to +90ºC
Shore A hardness (ISO 868): 65
Max. tensile (ISO 37): 2,50 MPa.
Modulus – elongation at 100% – (ISO 37): 1,70 Mpa. Max. tensile
Elongation at break (ISO 37): > 250 %

At $12 a tube I might just do all the membrane seams while I am at it to use up the tube!!!


Now I am a believer in things being too good to be true but at this point I am going to end up with one of the above alternatives or grab a $10 tube of silicone otherwise (Thats what a tube of MONO Silicone Pro is worth up here, don't even ask what a bottle of rum is cost)

Any thoughts?

[Elton Noway]

I was doing similar research, i.e., looking for a less expensive but quality alternative to Kerdi Fix. Some of the below may have already been covered in a earlier replies so please excuse any overlap. I learned Kerdi Fix is a SILANE based product and for quite a while it was the only one available because Schluter held the patent. The good news is the patent expired years ago and some recommended Silane based alternatives frequently mentioned here and in other forums are:

Wedi Joint Sealant
Sikaflex 505UV
Loctite 5510
OSI Quad Max

Wedi and Sikaflex seem to be the more popular suggestion so doing some further research on Sikaflex I stumbled across MasterSeal NP1 as a alternative ... suggested both here and in other forums. Seems via "word of mouth" is it was recommended by a Schluter rep! FYI: Per the MSDS it is also Silane based: (NOTE: copy/paste the blue text below into the URL field of your browser to be redirected)
bestmaterials.com/PDF_MSDS/MASTERSEALNP1ALUMINGRAYALSONP1ALUGRY.PDF

Anyway, below is a direct quote from another forum:

Re: Is Sika-flex the same thing as schluter-kerdi fix
I asked this question of a Schluter rep at a seminar and he recommended this to me as a replacement. Since it's available locally, I've been using it since.
bestmaterials.com/detail.aspx?ID=21113

No longer carried by the big Home warehouse but found it on Amazon. Curious if anyone here has tried NP1... pros/cons etc.

[RichVT]

NP1 contains isocyanates. No way I would use that in a customer's home.

You should be very aware of and careful about what chemicals you are introducing into someone's house.

[Elton Noway]

Good point... no argument from me... isocyanate vapors can be real nasty! However, for this current installation I'll only be using it seal the 60" gap between the front edge of the tub and the Schluter-DITRA. (i.e.short usage/exposure window) Then I'll immediately cover the joint with Schluter-Kerdi. I also use a respirator as well as a ventilation fan that exhaust to the outdoors whenever using toxic chemicals. The fact a that a Schluter rep suggested it when Kerdi Fix was not available has me intrigued.

[tommasden]

interesting thread. We just did a whole kerdiboard shower with https://retail.usa.sika.com/en/produ...ction-adhesive

I dont believe all the hype from shulter they cant even keep the story straight from us to eu...

https://www.jm.com/content/dam/jm/gl...alant-List.pdf

[jadnashua]

If you're referring to the modified versus unmodified between the US and the EU, the story I was told by Schluter is that to get unmodified approved in the EU required all of the countries to agree if they wanted an EU-wide approval. Their tests had proven it would work, but individual countries local practices just wouldn't allow a consensus. So, they went with a method they also know would work. The ANSI and Euro specs also make it easier to tell what class of products will work. The ANSI spec does not break down sufficiently to identify a particular product's modifier as being suitable for use with their membranes.

In the USA, they only had to get clearance from one agency to be approved for the entire market, and, they went with their preferred method. The issue is, and has been, that they know some modifiers will work. They do not have control over the manufacturers except for those made for them to their specs. So, it's not an easy thing to be testing various other products that could change on a whim to say they're compatible. As a result, they tell you what they're confident will work.