Retrofitting heating in Balham and Tooting houses
A side return or rear extension on a pre-1919 house in Balham or Tooting is usually where heating in the floor first appears. The extension floor is new, but it has to meet the original floor at the doorway, and the original floor is often being dug out and rebuilt at the same time because it has no membrane.
That creates a height budget. From the level of the finished floor down, you need the flooring, the screed, the pipes and enough insulation below to push heat upwards. The screed is the part with the least flexibility. Over the pipes, liquid screed has to be at least 25mm thick, so the whole layer is usually 45 to 50mm. Sand and cement wants around 45mm over the pipes on its own, which eats more height.
In a tight retrofit, that difference often decides it in favour of liquid screed around the pipes. Being runny, it surrounds every pipe without leaving gaps, so warmth travels evenly and the room heats up sooner.
On pour day we look for gaps in the insulation, make sure the membrane is down and confirm an edge strip runs round every wall to let the warm screed expand. Your installer should test the loops under pressure and leave them pressurised while we pour. Where insulation or membrane is missing, we can supply it; see insulation and membranes.
New apartments along the Nine Elms riverside
New building is easy to see along the river. 12% of homes in the borough have been built since 2015, and Nine Elms has changed from an industrial area into a district of apartments, offices and shops around Battersea Power Station. Those apartments specify liquid screed over underfloor heating, and redevelopment of the Alton Estate will bring more new build work.
On a new build, the screed depth and product are set by the design, and the heating is sized around them. Following the specification matters more than preference, because a thicker or different screed changes how quickly the floor responds.
Commissioning is where heated screeds are most often damaged. Calcium sulphate usually lets the loops run gently after 7 days; a sand and cement floor holds out far longer, to 21 days or more. The temperature is raised a few degrees at a time, held, then lowered before flooring goes down. Our screed drying guide explains typical timings.
For heated floors, liquid screed is published at £20 a square metre at the low end and £35 at the high end for 2026. Over the border in Lambeth, our Lambeth heated screed page applies.
Underfloor Heating Screed prices in Wandsworth
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 Wandsworth
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 Wandsworth
On the map, Wandsworth sits east-south-east of Slough, about 20.8 miles from our base in a straight line (postcodes including SW12, SW11, SW4 and SW18), next to Merton (2.8 miles), Lambeth (2.9 miles), Hammersmith and Fulham (3.7 miles) and Kensington and Chelsea (3.8 miles).
More on underfloor heating screed, part of our screeding services.