Which primer for a Liquid Screed floor? (prior to Ditra mat and tiling)

[Steveb21]

Liquid screed floor poured just under a year ago. It is due to get sanded tomorrow.

Which primer should i use to seal the floor? Can i use SBR/WATER mix? 1:3 ratio? or is it bestto use a acrylic primer?

BAL Prime APD Acrylic Primer For Walls and Floors - 2.5 Litre

BAL Prime APD Acrylic Primer For Walls and Floors - 2.5 Litre

www.victorianplumbing.co.uk

I will be using ditra membrane stuck with adhesive, then adhesive and tiles on top. Any suggestions for which brand/type adhesive to use would also be great!

 

[johnny2007]

BAL APD is fine.
Many similar products are available from different brands.
Mapei sell their own primers for different substrates (most popular is primer g).
Their technical department is very helpful so you can give them a call to get best advice.

 

[Mr Chibs]

I used Primer G from Mapei for my liquid screed floor, I used ditra mat too, all has been well, been down a few years now.

 

[Steveb21]

Thanks both.

Chibs,
What adhesive did you use for the ditra? was it same for the tiles?
I am looking at using Tilemaster Setaflex Standard Set S1 Adhesive for both. I may use Tilemaster Anhyfix for the Ditra though.

I may ask the next question on another thread as its slightly off topic, but will list here first.
How critical is it to commission the UFH before tiling?

Area of approx 60m2
UFH pipes and liquid screed was put down just under 12 months ago
Floor is being sanded today to remove any laitance

Due to other major works going on i am unable to commission the UFH. I do not have manifold or pump in place either.

As the screed has been down for just under 12 months, i will be very surprised if it has not fully cured/dried.
I will be using Ditra membrane so this will help if there is any movement/cracks when UFH is switched on (after tiling)

I was planning to start tiling in the next few weeks. Is commissioning the UFH critical? If so, I will need to figure out how i can get a temp source of hot water to the area of the manifold and pump.

 

[johnny2007]

Well, imagine if there's a leak...

 

[Steveb21]

UFH pipes were installed using a reputable company. In general the chances of UFH pipes leaking are very low. There are no joins in pipe work either.

Taking the leak scenario out of it. I am happy to take that risk. It is just the fact its never been heated up which concerns me.

 

[Mr Chibs]

With regard to primed pipework... I thought it was to do with expansion & leak detection.
I'm sure there are loads of floors laid like yours where the pipework hasn't been plumbed in.

As for leaks, you will only find out when it's pressurised. If they were careful when they laid the screed, (didn't damage the pipes) you shouldn't have a worry.

As for tile adhesive, I used this for the mat and stone tiles.
Rocatex S1

Think I did two coats of Primer G, I used a roller on a pole, as it's was quicker.

Good luck with it, will be worth it in the end

 

[Steveb21]

I had a word with the screed and UFH installer earlier..

I have decided to plumb in the UFH so will be a bit of work for a.temp setup just to get the UFH commissioned... but gives peace of mind before laying the tiles.

Thanks again