Force drying liquid screed

Force drying means using heat and dehumidifiers to dry a screed faster than it would on its own. On calcium sulphate, from day 7, with the underfloor heating or space heaters and dehumidifiers. On a cement-based liquid screed, the heating can go on from day 14, at no more than 45°C.

With the heating going up to 50°C, the cycle puts the first moisture test at about day 31, against about 42 days of natural drying for a 41 mm floor. Without heating, dehumidifiers and ventilation are the tools.

Get a free quote Call 086 838 2613

Free, no obligation. One local screeding contractor prices it, not five.

The heating cycle, day by day

Day 7
Heating on at the lowest manifold temperature, about 15°C. Hold it there for a day.
Days 8 to 14
Up by no more than 5°C a day: 20, 25, 30, 35, 40, 45, 50°C. Stop at the running temperature if it's lower; never above 50°C.
Days 15 to 21
Hold at the running temperature for 7 days.
Days 22 to 28
Down by 5°C a day, back to the starting point.
Days 29 to 30
Heating off for 48 hours to cool.
Day 31
Moisture test with a hair or digital hygrometer.

Without underfloor heating

Dehumidifiers from 72 hours, in a closed room, emptied regularly.
Space heaters with dehumidifiers. Never gas or other fossil fuel heaters: they add moisture.
Ventilation without draughts: windows and doors closed for 7 days on a cement-based liquid screed, then opened now and then, without air tunnelling through the building.

Rules that don't bend

Never above 50°C on calcium sulphate, or 45°C water on cement-based.
No more than 5°C a day, up or down.
The heating cycle runs before flooring, however dry the screed looks.
Sand and cement without a drying additive can't be force dried like this.

Then test

After the cycle, the moisture is measured by hair hygrometer, carbide bomb or oven test before any covering. Moisture testing.

Liquid screed poured by the contractor who takes your call

Calls on this site ring JAM Floor Screeding: James Mulhall, based in Portlaoise, 25 years laying floors. Lines open Mon to Sat, 7am to 6pm. These are his jobs.

Underfloor heating pipes clipped down in rows across a floor, ready for the screed — Underfloor heating ready for screed

A freshly poured liquid screed floor, still wet and shining, in a block-built room — Liquid screed floor

A pale grey levelled floor in a bright room, finished and drying — Levelling compound over underfloor heating

“JAM were punctual, professional and efficient and did an outstanding job on pouring our new floor as part of a renovation. Very highly recommend!”
David O'Keeffe, Google review

“Excellent work, laser level finish, neat and tidy worker, highly recommend.”
Cathal Kelly, Google review

“Top class work by james and his crew, highly recommend”
the duke, Google review

Quoted word for word from JAM Floor Screeding's Google reviews. Read them on Google

Related guides

Liquid screed guides & price breakdowns

Straight answers to what people ask most: itemised costs, specifications, planning or grants, and what to check before you book.

Cost & Pricing GuideLiquid screed cost in IrelandLiquid screed cost in Ireland: how a floor is priced per m², our price guide for levelling compound, primer and joint strip, and what moves the price.Read the guide →Comparison GuideLiquid screed vs sand and cementLiquid screed vs sand and cement: depths, drying, bays, reinforcement and laying rates side by side, and when each one is the better call.Read the guide →Specification GuideLiquid screed depthLiquid screed depth: 25 mm bonded, 35 to 45 mm floating in a house, 25 mm over heating pipes, and why thinner dries sooner. Call 086 838 2613.Read the guide →Timeline & PreparationForce drying liquid screedForce drying liquid screed: heating from day 7 (calcium sulphate) or day 14 (cement-based), up 5°C a day to 50°C, the 21-day cycle, then the moisture test.Read the guide →Specification GuideLaitance and sandingLiquid screed laitance: what it is, which screeds form it, sanding at 7 to 10 days and before flooring with a 60 grit disc. Call 086 838 2613.Read the guide →Specification GuideScreed moisture testingScreed moisture testing before flooring: 75% RH (0.5% CM) for calcium sulphate, under 75% RH for cement-based, hygrometer, carbide and oven tests, and wood…Read the guide →

More guides & resources: Tiles, wood and vinyl on liquid screed · Joints and bay sizes · Is liquid screed right for my floor ? · All guides & calculator hub · Technical & trade glossary · Frequently asked questions · All areas covered · About this site

Force drying questions

Can you force dry liquid screed?

Yes. From day 7 on calcium sulphate, with the underfloor heating or space heaters and dehumidifiers. From day 14 on a cement-based liquid screed.

How hot can the underfloor heating go when drying screed?

Up to 50°C on calcium sulphate, raised by no more than 5°C a day. Cement-based liquid screed: water no hotter than 45°C.

How long is the commissioning cycle?

Typically 21 days: a day at about 15°C, up 5°C a day, 7 days at the running temperature, down 5°C a day, then 48 hours off before testing.

Can I use a gas heater to dry screed?

No. Gas and paraffin heaters raise the humidity.

Liquid screed across all 26 counties

Requests from all 26 counties go to one vetted local specialist who covers your county — from Dublin, Cork, Galway and Limerick to Kildare, Meath, Wicklow, Waterford and Donegal. Pick your county below for local prices, specifications and advice. Compare all areas covered →

Get a free quote for your floor

Four taps and your number. One screeding contractor who covers your county rings you with a price. Nothing is booked until you say yes.