Calcium-sulphate liquid screed
Anhydrite Liquid Screed in Exeter & Devon
The original liquid screed chemistry. Excellent for UFH-heavy residential builds where thermal response and cost matter more than wet-area exposure.
Price an anhydrite pour
Name, phone, email — we'll reply the same working day with a fixed price.
Or call our landline on 01392 237700
Anhydrite — or calcium-sulphate — screed is what most people mean when they say "liquid screed". Gyvlon and Gypsol are the two names you'll see quoted most often in the UK. It self-levels, encapsulates UFH pipework beautifully and pours at rates a hand-laid sand-and-cement gang simply can't match.
It has real advantages: strong thermal conductivity, no bay joints, and a lower per-cubic-metre cost than most cement-based liquid screeds. But it also has a real limit — it does not like being repeatedly wet, and it needs the laitance sanding off before floor coverings.
This page explains where we'd choose an anhydrite screed, where we wouldn't, and how a Gyvlon or Gypsol pour actually runs in practice.
When anhydrite is the right screed
- Standard residential extension or new build with UFH
- Engineered wood or LVT going down over foam underlay
- Programmes where cost per m² is a bigger driver than exposure risk
- Deep pours (50–80mm) where cement mixes would want more curing time
- Areas without recurring water exposure — bedrooms, living areas, hallways
When we'd steer you off anhydrite
- Wet rooms and en-suites with power showers
- Kitchens with poor detailing around dishwasher/washing-machine bays
- Basements or ground-bearing slabs with a marginal DPM
- Anywhere epoxy, polyurethane or polished-concrete finishes are planned
- Cement-based tile adhesives without an isolating primer
How an anhydrite pour actually runs
- 1
Prep
Perimeter foam, taped DPM, UFH pressure-tested and clipped down.
- 2
Datum
Laser levels set. Datum pins pushed through the insulation to true finish level.
- 3
Pump
Static mixer on the drive, hose fed through the property. 20–40m³ per pour is normal.
- 4
Dapple + spike-roll
Two passes of the dappling bar to break surface tension, spike-roll to release air.
- 5
Protect + dry
48h no traffic, then controlled ambient drying. Sand the laitance before tiling.
Anhydrite is a brilliant screed for dry residential builds with UFH. Put it in a wet room and you'll be back in a year to lift it.
— Exeter Liquid Screeders
Frequently asked
Price an anhydrite pour
Send us the area, depth and build-up. We'll quote against Gyvlon or Gypsol and flag anything worth reconsidering.