Problem with Wundafloor panels, primer and screed

[fullbreakfast]

Hoping someone can help me with a question. We have laid Wundafloor heating panels onto an existing solid floor. Their installation instructions are here:

Install floor heating using overfloor panels

The panels have an aluminium coating to the top surface, we are planning to put white marble tiles on top. The relevant part of their instructions:

"Light porous stone, eg. Travertine:
Use Mapei Eco Prim Grip to prime panel to bond with Mapei Ultraplan self levelling fibre reinforced screed at encapsulate the system panels to a depth of 3-5mm. Then use Mapei Grani-rapid white or Mapei Keraquick and Mapei additive Latex Plus adhesives for laying stone tiles."

I bought the materials but today our tiler came and I was out. He has put down the screed without putting a layer of the Mapei Eco Prim Grip primer onto the panels first :mad2:. The screed is now drying - with worrying bubbling to the surface in some places - and the guy is supposed to be coming back tomorrow to lay the tiles. I'm worried that the screed won't bond to the aluminium without a primer layer and if we put on the tiles now we will end up with an unstable floor that will cause us big problems, wondering if we need to scrape off the screed and start again. I can't get through to Wundafloor's office to ask what they think until Monday.

Has anyone got any experience with this? Seriously stressed!

Many many thanks if anyone can offer any help.

Cheers!

 

[ruairi mac]

Hi, I haven't used those panels personally but I would say that you will definitely need to prime them. The eco prim and ultraplan are top quality stuff. The bubbles to me would suggest that there was just air trapped and the bubbles is just the air escaping.

 

[fullbreakfast]

Thanks for the reply ruari. Looks like we will have to replace the whole underfloor system as Wundafloor and Mapei have advised that without the primer layer the screed will oxidise the aluminium. Tried removing the screed layer in the hope of salvaging the panels underneath but it's a hopeless job. About £1000 down the chute :mad2:

Now looking for someone who can do the bloody job properly!

 

[ruairi mac]

Sounds like a nightmare mate. at least you caught the problem before he tiles went down, you would be looking at a whole lot more than a grand if you hadn't.

Has the tiler offered any help with the new boards or was he chased quickly down the road? Where are you based?

Some times it's hard to keep up with new materials on the market but if he'd done a half hours research on the internet he would've been fine.

Hope you get it sorted.

 

[fullbreakfast]

Sounds like a nightmare mate. at least you caught the problem before he tiles went down, you would be looking at a whole lot more than a grand if you hadn't.

Has the tiler offered any help with the new boards or was he chased quickly down the road? Where are you based?

Some times it's hard to keep up with new materials on the market but if he'd done a half hours research on the internet he would've been fine.

Hope you get it sorted.

Very true - was not going to risk wasting 30 sq m of Carrara marble tiles by laying them on dodgy foundations!

Tiler is helping replace the panels without charge and will probably lay the tiles (as a tiler I believe he is actually good). Not trusting him to lay the screed this time though so looking for someone who can do that! We're near Leatherhead.

 

[fullbreakfast]

Hmmm. Now the guy is saying that the tile adhesive I've bought isn't really suitable. It's Mapei Grani-Rapid White (2 part). This is to use with 405mm x 405mm x 10mm white marble tiles on a kitchen floor. He reckons this is very quick drying and will be hard to work with for this application, says more suitable for bathrooms. Which is frustrating because it's what the manufacturer of the heating panels recommends using and I've bought the damned stuff.

 

[The Legend; Phil Hobson RIP]

Not used Grani-Rapid, but not sure why your tiler has a problem with it, most rapid sets go off in three hours. Maybe worth a call to Mapei tech dept, I can't see what the problem is myself. Mapei are a top adhesive manufacturer, give them a ring, and good luck.

 

[ruairi mac]

As above, anything from Mapei is a quality product. Cant understand why you tiler isn't keen to use the stuff. I there a difficult layout of the floor??

The eco prim I believe is just applied with a roller, and the ultraplan renovation screed should do all the hard work for you regards levelling as long as you mix the correct amount of water with it.

The Grani rapid shouldn't go off any quicker than an average fast set adhesive however if you believe the tilers good ,and you want to use him and if it's possible Mapei also do a slow setting, white, 2 part adhesive. The latex you already have should be the same, you would only need to swap the bags with your supplier.

Best of luck.

 

[sstilingservice]

Perhaps your tiler is worried with doing the work as he mucked the sub layer so wants to make sure he's under no pressure with regards to the adhesive setting to quick. No point rushing to fit tiles befor adhesive sets if you don't have to :0) good luck

 

[Ivor solador]

I have used Mapei Products extensivley and have alway found them to be excellent, it is imporatant that you follow their guides when laying either adhesives or renovation screeds, if you do so then you will have no problems. I have had occation to tile onto Wunda's overfloor panel with limestone tiles. I followed both Wunda's and Mapei instruction for laying down the renovation screed onto the panel using the eco primer to coat the panel first, this dried with no problems. I then laid the tiles using the 2 part adhesive (called kerrabond and isolatic i believe) the customer had purchased from Wunda, it was a slower setting adhesive, designed more for the amature, but the result was excellent and I was very confident that the customer would have no problems in the future.