Faq’s Liquid Screed


What is the minimum depth on insulation screed can go?

With Liquid screed the minimum depth is 35mm with our Flow Xs


What is the minimum depth with underfloor heating screed can be?

You can install the screed 20mm above the top of the pipes with Flow HTC


How much does Liquid screed cost?

This depends on the size and depth of the area, but generally between £12.50 and £17 per m2


How long does screed take to dry?

You can walk on the screed in 24 hours. For the screed to receive floor coverings it drys at 1mm per day up to 40mm, then 0.5mm per day after. 

You can force dry after 7 days with a dehumidifier or underfloor heating. Read our drying guide here


Do I need to fill my underfloor heating pipes up?

Yes, not only to check for potential leaks but also to stop the pipes from floating in the screed.


Do I need to sand the screed?

You only need to sand the screed if you are sticking any flooring down. Its good practice to sand so you can remove any plaster and construction debris.


Do I need to prime the floor before tiling?

All screed should be primed before using either self-levelling or adhesive. This is to stop the products being sucked dry.


Do I need expansion joints in the screed?

Bay sizes can be up to 40m with liquid and 8m with traditional.


Can I screed on Joists?

Yes, you can as long as the joists have been engineered to take the weight. See our guide here.


Do I need a slip membrane or Vapour barrier on top of the insulation?

Yes, this is required for all ground floor construction but is also needed to stop the screed lifting the insulation and creating cold bridges.