Heated extensions on Gosport's post-war semis
Of Gosport's homes, 28% are semis and 36% were built between 1945 and 1972. Plenty of those post-war houses have room for an extension, and a new kitchen or family room on the back is just the place where heated floors earn their keep. It is the screed that does the work here: it wraps the pipes, carries the warmth across the room and gives your flooring something flat to sit on.
Start with the cover. Pumped screed must clear the top of each pipe by 25mm or more, so a Gosport extension floor finishes 45 to 50mm deep; laid by hand, sand and cement needs roughly 45mm over them. With too little cover, cracks can follow the pipes across the floor; with too much, the new room on the back of your semi warms up slowly.
A liquid screed runs right round each pipe and leaves no voids, so the floor heats up quicker and the system runs more efficiently. Hand-laid screed works as well, provided it is packed down carefully around the pipes. Whichever you choose, we look over the insulation boards, the membrane and the strip round the walls first, and supply anything missing, because a gap in that edge strip lets the screed bond to the wall.
Extensions add a height problem. Insulation, pipes, screed and flooring stack up thicker than an unheated floor, yet the new room still has to come out level with the old one. Fix the dig depth before the foundations go in and there is no step at the door. Depths are listed in our guide to screed thickness, and the pour is covered under Gosport liquid screed pumping.
Switching the heating on in a Gosport home
Please do not turn the heating up full the day after we pour. Give calcium sulphate about 7 days before any gentle warmth goes through it, and give sand and cement 21 days at minimum. Even then the start-up is slow: a low flow temperature to begin, raised a little at a time over several days, held at running temperature, then lowered again before the flooring is laid. The schedule comes from your heating engineer, and we explain it clearly so screed and system are treated the same way.
Running the heating to force dry a calcium sulphate floor also helps it reach the moisture reading flooring makers ask for. You still need a hygrometer reading before tiles or timber are laid.
Retrofitting is harder work. In an older Gosport terrace, lifting the floor to make space for a heated screed can foul doors, stairs and thresholds, so the old floor often gets dug out instead. If a room is being rebuilt after a failed solid floor anyway, hand-laid sand and cement for the terrace may suit its wet rooms, with liquid screed in the other rooms. Published costs for heated liquid floors are in our guide to what screeding costs.
Underfloor Heating Screed prices in Gosport
Liquid screed over underfloor heating: £20 to £35 per m² supplied and laid (trade2base, June 2026), so £700 to £1,230 for 35 m². trade2base gives these figures excluding VAT. See our floor screeding cost guide or screed calculator.
Who lays your underfloor heating screed in Gosport
K & B Screeding’s own team, led by director Donatas Bardisevicius. Founded 2019, company 12298780.
See what customers say in our Google reviews and on our testimonials page.
Underfloor Heating Screed from Slough to Gosport
As the crow flies, our yard in Slough is about 55 miles from Gosport, which lies to the south-south-west. Postcodes here include PO12 and PO13, and Portsmouth (1.4 miles), Fareham (4.6 miles), Havant (7.4 miles) and Emsworth (8.9 miles) are close by.
More on underfloor heating screed, part of our screeding services.
