Pipe cover in a heated Chesham kitchen extension
Underfloor heating depends on its screed. That layer grips the pipes, spreads their warmth and carries the finish, so it needs enough depth over the pipes and full contact all round them.
For a pumped liquid screed in a Chesham extension, leave at least 25mm above the pipes, which normally gives a floor 45 to 50mm deep. Pumped in, it wraps each pipe without air pockets, so the floor warms faster and runs more efficiently. With sand and cement, plan on about 45mm above the pipes, packed carefully round the pipes so no voids are left. How a pumped pour gets to the room is covered on our liquid screed page for Chesham.
Semis make up 31% of Chesham's homes, and a back extension on one has a fixed target: the new floor must meet the existing kitchen or hallway. Start from that line and work down. The finish, screed, pipes, insulation and membrane all have to fit between the new slab and the old floor level. If they do not, swap the insulation or screed choice before the slab goes in, while that is still easy. On a Pond Park semi, that might mean thinner insulation boards, or a liquid screed in place of a thicker sand and cement one.
On the day of the pour, the edge strip, membrane and insulation all get looked over first; if you still need them, our insulation and membranes service supplies them.
Retrofitting heating into older Chesham ground floors
Retrofitting heating into a house that already stands is trickier than designing it into an extension, since the doors, stairs and skirting already fix the floor height. In a Newtown terrace that is losing its old solid floor anyway, the dig-out gives room for insulation, pipes and screed, so that is the moment to add heating.
Of the town's homes, 12% date from 1919 to 1944. When an older floor stays put instead of being dug out, a thinner liquid screed over the pipes can keep the build-up within what the doors will allow. If the room is a bathroom, put sand and cement over the pipes; calcium sulphate is the wrong material for a floor that might get wet.
Bring the heating up slowly. Calcium sulphate will usually take its first gentle warmth after around 7 days, sand and cement not until at least 21, and from there the flow temperature goes up in small steps across several days. Turning it straight up can crack the screed, so settle the schedule with your heating engineer.
Underfloor Heating Screed prices in Chesham
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 Chesham
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 Chesham
As the crow flies, our yard in Slough is about 12 miles from Chesham, which lies to the north. Postcodes here include HP5, and Amersham (1.9 miles), Berkhamsted (4.5 miles), Chorleywood (5.2 miles) and Tring (6.5 miles) are close by.
More on underfloor heating screed, part of our screeding services.
