Polypipe Overlay Advice

[AliGage]

Apart from the one I did with Marc the last time I tiled straight over these boards was two years ago. I'm about to do a second, for the same builder.
The builders had repeat business from the client two years ago. The floor is ad spot on now as it was when it went in.

I've got another now for the same builder. Only difference this time is its travertine rather than polished porcelain.

Now he's levelled the floor with slc, glued the boards with no nails or an equivalent and screwed straight through also.

I posted a little while back about this system with this job in mind:

Polypipe says no to SLC, they also suggest tiling direct.
There is absolutely minimal expansion in these boards, yet with stone it's recommended to decouple. But i fail to see any advantage to it direct to the boards.

Absolutely right @widler it's a minefield. Every possible option will have someone frowning, not guaranteeing or suggesting alternative methods.

 

[AD Ceramics]

don't listen to a word they say, how can they spec a system to install tiles on there product when they don't even do tests they're technical are clueless.
I did one a few years ago and they told me to tile straight on top with a spf no priming either and leave the boards floating, I'm pretty sure there boards are gypsum based or was gypsum based at the time when I installed my floor.
The only adhesive company that would commit at the time was Norcross and they required the boards fixed in to the timber floor below Then primer until no more would soak in. Then slc 10mm thick and then that would give the strength of over plying in 18mm. Then a spf adhesive. They insisted that decoupling mat wasn't required even though it was a limestone going down and the customer didn't want the added cost so straight on top. It must be three years or more and no problems with it.

 

[Old Mod]

Tilemaster are of similar opinion!
Spoke at length with @Glynn recently on the subject.
They would prefer 5-10 SLC then their crack mat for stone installation.
If no mat they'd want their S2 ultimate used as adhesive.
I think, haha it's been few weeks. 🙄

 

[widler]

Which ones Craig?
Polypipe or overlay?

The polypipe boards marc, the 1st one i did a few years ago were screwed into the substrate then just tiled ontop of the pipes .
I actually don't see the advantage of putting cement boards ovr the top, i don't see it being a problem but i don't see a advantage 🙂

Id ask your tiler or maybe someone off here is in your area, some nice lads one here @moodle

 

[Old Mod]

The ends of the boards are meant to be glued together when installed, making one big sheet!
At least that's how it was explained to me!
However, I'd still fix a few screws through boards to reassure myself.
But as u can imagine, once the boards are one, then pipes and water, it would be a pretty heavy installation which in theory doesn't expand or contract. 🙄

The boards prevent the pipes being encased in SLC which they say will make it fail!

They're only happy with adhesive because it's not fluid and sits on top!

I'm certainly not saying they're correct.
Personally I'd put my faith in the adhesive companies!
It's them I'm relying on to achieve a successful install not bloody Polypipe!

 

[moodle]

Thanks all, this is very useful! Don't suppose there are any tilers with experience of this system in the Liverpool area?

 

[AD Ceramics]

Thanks all, this is very useful! Don't suppose there are any tilers with experience of this system in the Liverpool area?

Ay up moodle. I'm in Manchester if that's any good if you need anything.

 

[widler]

Bit far for me,that drive down the m60/62 drives me insane, id end up doing time for muuurrrrdder if i drove down thatthing for more than 5 days 🙁

 

[AliGage]

Out of interest @3_fall why is SLC spec'd by TM.
There's a lot of sense to SLC over electric UFH. A lot of positives to its use.

The way I see it there boards are effectively a cement backer. The pipes are never going to "Float" out. The piping is a barrier pipe so it's expansion is accommodated and very minimal.
With all that in mind I see no benefit to a decoupler if tiled direct.
If the floor is sound and level and the boards are as such too. I see no need to SLC.
So surely a flexible adhesive is more than apt?

 

[AD Ceramics]

Norcross said the slc was to strengthen and make sure no air pockets around pipes. The only way they would spec the job.