Self-leveling compound - waterproofing membrane, different manufacturers?

[mattetvilling]

The craftsman I have chosen to level the floor will use CM 780 Snabb Fiberavjämning. Can I use any approved waterproofing system on top of this? Or does anyone know which systems can be used on top of Combimix Flytspackel? I have found Ardal but was perhaps more inclined towards Casco or Lip.

 

[Eddi Thomason]

If you follow BKR, it is the instructions of the waterproofing system that apply. But in practice, it probably matters less! My understanding is that it mainly concerns the fact that the waterproofing supplier has tested and certified their system with their self-leveling compound (or other specified) and can therefore guarantee adhesion. But how much difference can there be in adhesion to different brands of self-leveling compound?

 

[mattetvilling]

If you follow BKR, it's the waterproofing instructions that apply. But in practice, it probably doesn't matter much! My impression is that it's mainly about the waterproofing supplier having tested and certified their waterproofing with their own levelling compound (or another specified one) and thus can guarantee adhesion. But how much difference can there be in adhesion against different brands of levelling compound?

I also don't think it matters, possibly you should use a compound with the same structure that resembles the waterproofing manufacturer's compound. For example, Aluminatcement (with some inclusion of Portland cement) with a flow additive.

Is there someone who works with Combimix who knows what kind of waterproofing is usually applied on it?

I just called Combimix, and they said that it doesn't matter which levelling compound you use under the waterproofing, but they have to say that because otherwise, there would barely be any waterproofing you could apply since they don't sell it themselves. He also said that in the instructions for the waterproofing, it usually states that you should use the brand's own compound, but that somewhere in the fine print it mentions you can use others.

 

[vectrex]

Oh, is it time for spackling now? I'm guessing the craftsman considering the combimix...

 

[mattetvilling]

Oh, is it time to start plastering now? I'm guessing the craftsman considering combimix...

He he, yes, he seemed trustworthy. Thanks for the tip. Just need to put some boards on the walls and some pipes on the floor. What waterproofing did you use?

 

[vectrex]

Lip, but I had already bought Lip self-leveling compound so he used that. Significantly more expensive than Combimix.

 

[mattetvilling]

Lip, but I had already bought lip leveling compound so he used that. Significantly more expensive than Combimix.

Yes, that might be a solution. But you want the craftsman to use what he is familiar with.

This thread might have belonged in the bathroom section to get some answers from the experienced. Can a moderator move it there?

 

[mattetvilling]

Called Casco because I was planning to use their Casco WetStop 1 Folie, and the technician said that you can apply their waterproofing system to any leveling compound as long as you follow the compound manufacturer's instructions.
So it's only the waterproofing system (folie/fix/fog) where you have to use the same manufacturer/system.

When I asked why it's not stated in their folder/instructions, the answer was that they prefer people to use their products, but they should write that it's okay to use other products and still be approved.

 

[injonil]

It is unfortunate that manufacturers do it this way as it decreases the credibility of what they write in their instructions. It is likely the same with primer, which normally can be used universally with all self-leveling compounds. However, if a manufacturer has a special composition in their compound that requires their primer with tailored ingredients, then many might make mistakes.

OT: Jafo makes nice drains, but the instructions were lacking in one aspect. It explicitly stated that the drain required a cc300 floor joist spacing and two noggings in between to form a box. Nothing was mentioned about the dimensions of these noggings. Now, I know it's perfectly possible to achieve a robust construction with cc600 and three substantial noggings (e.g., 145mm, which I used), but I didn't follow the instructions, and thus an insurance company could potentially deny me compensation if water damage occurs at the drain.