Traditional semi-dry screed
Sand and Cement Screed — Semi-Dry, Hand-Laid Floors
Liquid screed is our everyday floor, but it self-levels dead flat and gypsum mixes dislike standing water. When a job needs a fall, an upstand or a wet-area base, we lay a traditional semi-dry mix by hand instead.
Need a fall, a wet room base or a threshold?
Name, phone, email — we'll reply the same working day with a fixed price.
Or call our landline on 01392 237700
Short answer: a semi-dry screed is sand and cement mixed with just enough water to bind, placed in bays, compacted and trowelled flat by hand. It is slower than a pumped pour and dries more slowly, but it can be shaped — which is exactly what wet rooms, balconies, drain falls and external steps need.
Most of the floors we lay are flowing screeds, because they are quicker, flatter and wrap underfloor heating pipes without air gaps. This page exists for the jobs where that strength becomes a weakness. A liquid mix finds its own level, so it cannot hold a fall towards a gully; and calcium sulphate mixes are not designed to sit in sustained wet. Sand and cement has neither limitation.
It also suits awkward sites. The mix can be barrowed where a pump lorry cannot reach, or on larger jobs delivered through a screed pump and still finished by hand. Deep make-up floors over a dug-out sub-base can be built up in layers rather than in a single deep pour that would take months to dry.
Semi-dry or liquid — how we decide
Choose semi-dry sand and cement
- A fall to a drain outlet has to be formed in the screed
- Wet rooms, shower areas and balconies with regular water
- External thresholds and steps tying into indoor levels
- Deep fills or feathering into an existing floor level
- No pump access and the mix must be barrowed in
Choose a flowing liquid screed
- Large flat internal floors
- Underfloor heating that needs full pipe encapsulation
- SR1 flatness for large-format tile or resin
- A programme that needs the floor dry sooner
- Open-plan areas where bay joints are unwanted
How a hand-laid screed goes down
- 1
Survey the floor
We check the substrate, the depth needed, where falls must run and how materials will get in — barrow, bucket or pump.
- 2
Prepare and set out
Priming or an SBR slurry for bonded work under 40mm, or a DPM and separating layer for floating work. Bay lines and laser levels are set.
- 3
Place and compact
The mix — typically 4:1 or 5:1 — is laid bay by bay and compacted as we go so no voids are left behind.
- 4
Trowel to finish
Hand float or power trowel to a dense SR2 surface, within 3mm under a 2m straight edge.
- 5
Cure and inspect
Protected while it cures, then checked before tiling or other coverings start.
Depths we work to
| Build-up | Typical minimum |
|---|---|
| Bonded to a sound slab | From 25mm |
| Unbonded or floating over insulation | From 50mm |
| Falls and dug-out sub-bases | Built up thicker as the fall or fill requires |
Drying — the honest part
The rule of thumb we give customers is roughly a day of drying for every millimetre of depth once you are past the first 50mm. In practice a 65mm floor is usually ready for coverings in around six to eight weeks, with ventilation and site conditions moving that either way. That is the main reason we steer large internal floors towards liquid screed instead.
Bay joints and polypropylene fibres keep shrinkage cracking under control, and we set joints at doorways and depth changes, where stress naturally concentrates. Tiling over a crack that was always going to open is a problem we would rather design out than repair later.
Useful to know before you book
- It can go over underfloor heating, but warm-up is slower than a liquid screed because hand-laid mix leaves small voids around pipes
- Material is cheaper per square metre, labour is higher — on small or awkward jobs the total often comes out similar
- We match new screed to an existing finished floor level, allowing for the covering that goes on top
- For SR1 flatness under large-format tile or resin, liquid screed is usually the better route
Frequently asked
Need a fall, a wet room base or a threshold?
Tell us the depth, where the water needs to go and how we get in, and we will say whether semi-dry or liquid suits better. Call 07791 510849.