I'm experiencing a mental block - help please

[Daz]

Okay, It's late and I'm still working on quotations :mad2:.

I have to price a kitchen / garden room (44sqm total) for 600 x 600 travertine with electric UFH (2 separate thermostats). The garden room will have a new screed so there is an opportunity to leave it 10mm lower than the kitchen level so that 20mm insulation boards can be used in the garden room and 10mm in the kitchen. I'm thinking that I should specify a decoupling membrane to be applied over the UFH - correct? Is it still advised to slc over the ufh prior to installing a decoupler or can I just ensure a good adhesive bed over the wires and fix the decoupler to that?

What would you spec, please?

Cheers,

Daz

 

[doug boardley]

slc over ufh, then de-coupler Daz

 

[Pebbs]

Ummm I go ufh then self level and then decoupling membrane. Saying that how much self levelling are you going to use?

Lynn

 

[Time's Ran Out]

Daz - I'd put a skim of fast set flexible over the ufh - then fibre enhanced slc - then fast set flexible adhesive to fix decoupling layer.

 

[Daz]

Ummm I go ufh then self level and then decoupling membrane. Saying that how much self levelling are you going to use?

Lynn

A boat load Lynn, I usually spec at 2sqm per unit. I normally use Arditex NA with Latex so quite expensive :yikes:

 

[Daz]

Daz - I'd put a skim of fast set flexible over the ufh - then fibre enhanced slc - then fast set flexible adhesive to fix decoupling layer.

Thanks TJ. Do you skim with rapid set prior to UFH so that you get more sqm from the slc?
Does this work out cheaper than just pouring slc over the wires?

 

[Pebbs]

It would certainly be more cost effective that way, and there shouldnt be a problem by doing what John has bought to the table.

Lynn

 

[Time's Ran Out]

Rapid set FLEXIBLE (webber grey is only £11-00 bag) so yes its the price as opposed to SLC but it also holds the wires down/in place better before you pour the SLC

 

[Rob Z]

Rapid set FLEXIBLE (webber grey is only £11-00 bag) so yes its the price as opposed to SLC but it also holds the wires down/in place better before you pour the SLC

Captain, we use the same method/reasoning as what John is saying here. The first time I had a "floater" wire that buoyed itself up in the SLC pour (too late to do anything about it :mad2: ) was the last time. So we skim the wires to lock them in place.

 

[Rob Z]

Sorry to derail your thread Captain, but we don't use insulation boards here under UFH, and it caused me to wonder what the heat content is for your electric mats in the UK?

Here they vary typically from 12-15 watts/square foot. Doing the conversion, that ends up as 129-161 watts/square meter. How does that compare to your mats?

 

[faithhealer]

about the same I think Rob, anything from 140 to 200 (for conservatories)

What are your warm up times then Rob?

 

[SandyFloor]

I recently screeded an electric mat for vinyl tiles and it took two hits to cover the mat properly due to the mat floating even though it was well fixed. Next time I will be using rapidset as mentioned above and then slc. I wish this had come up three weeks ago and it would have saved me a bit of grief.

 

[doug boardley]

anybody else use a grout float to stick heat mat down with rapid set?

 

[Ken Bruty]

I would do that Doug, if I was setting it into rapid set

 

[chrisroe]

an epoxy grout float is even better harder rubber