Heated kitchen extensions on Lower Sunbury semis
Semi-detached houses make up 28% of homes in Sunbury-on-Thames, and in Lower Sunbury many have been extended at the back or wrapped round the side. The new floor usually carries insulation, a membrane, the heating pipes and then the screed. The finished level must line up with the old kitchen floor, so the depth of every layer is decided at the planning stage, not on the day.
The screed has two jobs over heating. It must encapsulate the pipes with no air pockets, and it must spread the heat evenly. Pour liquid screed and the pipes want 25mm minimum on top, so the finished screed is 45 to 50mm deep. Sand and cement needs nearer 45mm over them, making a thicker floor. That difference can decide which one fits under an existing door.
Pipe laying belongs to your heating engineer, as does the pressure test. Our part begins with a look at the edge strip, insulation and membrane, and anything absent can come from us as part of our work on insulation, membranes and screed preparation.
For a large open plan, pumped liquid screed over the heating is usually the efficient choice, because it flows around every pipe and warms up faster. Heated liquid floors cost from £20 per m² up to £35 on 2026 UK figures.
Where new heated floors meet older Sunbury-on-Thames slabs
Not every heated floor goes into a new extension. Heating can also go under an existing room, but in a house of this age the floor height is tight. Adding insulation, pipes and a screed on top of an old slab can raise the floor too far for doors and stairs. The options are to dig down and rebuild, or to use the thinnest compliant screed over the pipes.
The heat-up is the other step that needs care. Calcium sulphate can generally have warmth from around the 7 day mark. Sand and cement needs three full weeks, 21 days, before any heat goes in. Then the flow temperature is stepped up slowly across several days, kept steady, and eased back, all to the commissioning plan your heating engineer writes. Hurry that and cracks can open.
With 21% of Sunbury homes detached, some heated floors run through every downstairs room, and those follow exactly the same rules, only bigger. How long each screed needs to dry sets the waiting times out in full. The same service nearby is set out on our Weybridge underfloor heating screed page.
Underfloor Heating Screed prices in Sunbury-on-Thames
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 Sunbury-on-Thames
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 Sunbury-on-Thames
As the crow flies, our yard in Slough is about 12.5 miles from Sunbury-on-Thames, which lies to the south-east. Postcodes here include TW16 and TW17, and Ashford (2.1 miles), Walton-on-Thames (2.3 miles), Weybridge (3.7 miles) and Chertsey (4.1 miles) are close by.
More on underfloor heating screed, part of our screeding services.
