Which SLC over heating mats on insulation board

**WannabeMKII** · 02-02-2011

Hi all,
We're half way through preparing to tile a 20sq meter floor, but has been put on hold due to a forced change in tile.
So far, we've 6mm EkoBoard (which I bought through this site) covered with electric underfloor heating mats.
We're having a 600 x 600 porcelain tile, so need to SLC the current floor due to weight and having a level surface.
However, we've been quoted £200 for 4 bags of SLC to cover 20sq. To me, this seems really expensive, but have been told this is good SLC especially for UFH.
Is there really such a things as specialist SLC for UFH, or is there just a particular SLC that people would recommend in our position? As just levelling is going to cost £260.
Any comments and feedback welcome, as we'd really like a second opinion.
Thanks in advance.

doug boardley · 02-02-2011

do you have a Tile Giant near you? http://www.tilegiant.co.uk/stores

**Sir Ramic** · 02-02-2011

Get hold of Mapei Ultraplan renovation screed. Good price and fantastic to use.

Mapei Renovation Screed

**WannabeMKII** · 02-02-2011

Originally Posted by doug boardley

do you have a Tile Giant near you? Store Finder

We certainly do. But what should we be looking at, as it only appears they have one option on their site?

**WannabeMKII** · 02-02-2011

Originally Posted by Sir Ramic

Get hold of Mapei Ultraplan renovation screed. Good price and fantastic to use.

Mapei Renovation Screed

Sounds good, but where can it be purchased from and how much is it? I'm guessing 4 bags would be needed?

**Sir Ramic** · 02-02-2011

Originally Posted by WannabeMKII

Sounds good, but where can it be purchased from and how much is it? I'm guessing 4 bags would be needed?

Ask them to order it in. It should do 6m2 at 3mm but I would say that is at best even so 4 bags should do the job to just cover the UFH cables. I would probably get 5 to be on the safe side but thats just me and I could always use the leftover on another job.

**WannabeMKII** · 03-02-2011

Thanks for all the advice guys appreciated!

Just a quick question, is it ok/safe to use the plastic roller with small spikes to roll the SLC as you would on a none UFH situation, or could it damage the wires?

Thanks.

**WannabeMKII** · 03-02-2011

Originally Posted by WannabeMKII

Thanks for all the advice guys appreciated!

Just a quick question, is it ok/safe to use the plastic roller with small spikes to roll the SLC as you would on a none UFH situation, or could it damage the wires?

Thanks.

Ignore this question, I've found the answer and it appears to be safe.

**Sir Ramic** · 03-02-2011

The most important thing is to make sure the mats inc wires are secured to the floor to stop them from floating to the surface when you lay the SLC.

**WannabeMKII** · 03-02-2011

Originally Posted by Sir Ramic

The most important thing is to make sure the mats inc wires are secured to the floor to stop them from floating to the surface when you lay the SLC.

Hmm, that could be an issue. It's stuck down, but it's loose in places.

Is there a particular tape that can/should be used to stick it down?

**Sir Ramic** · 03-02-2011

Mix some stiff adhesive up and hold it down with that in areas that you feel could move. Let it set and the SLC.

**Ken Bruty** · 03-02-2011

Originally Posted by WannabeMKII

Hmm, that could be an issue. It's stuck down, but it's loose in places.

Is there a particular tape that can/should be used to stick it down?

Or, if you have a hot glue gun, just place a blob of glue under the loose bits and lay into it while it's still molten, works a treat.

**WannabeMKII** · 10-02-2011

Just following up on this and reading the pdf on the ultraplan renovation SLC, they advise priming the surface before using it? Is this really necessary over UFH and insulation board, or is it overkill?

**Barry bp** · 19-02-2011

You dont need to prime insulation boards

**Martyn Leeds** · 19-02-2011

just wondering about the spiked roller question asked previously on this thread..

I presumed you wouldn't be able to use spike over ufh in case you damaged the cables?

my next job is a floor with a cosytoes ufh mat, to be levelled over. Have i to treat myself to a spiked roller and try it out on this? or is it best to not bother??

**Sir Ramic** · 19-02-2011

Your spiked roller will not harm cables as the spikes are made from plastic.

doug boardley · 19-02-2011

the spiked rollers are designed to remove the air bubbles, I suggest you leave your slc in the tub for 2 minutes so that the entrained bubbles will disperse in the tub. I also think that you're maybe being a bit optimistic that 4 bags will do to cover your ufh, I'd be thinking 6 would be nearer the mark.