Project Overview
Interior Screed Group were instructed to install a high-performance screed over a newly prepared underfloor heating system for a private residential project.
The client wanted a durable, standard-drying screed compatible with UFH and suitable for LVT flooring.
We installed 32m² of Tarmac Tuff Screed at 65mm thickness to deliver an even, thermally efficient screed layer.
Scope of Work
- Review sub-base preparation and confirm suitability of UFH insulation boards.
- Lay 65mm sand & cement Tarmac Tuff Screed (batched externally)ideal for use with UFH applications.
- Compact, level and hand-trowel the screed to achieve a smooth, closed finish ready for final flooring.
- Ensure curing protection and issue aftercare instructions.
Challenges
Advised the client the UFH insulation needed precise levelling, The insulation had several minor high and low spots which, if left untreated, would affect screed depth and UFH performance.
Tight tolerance for a 65mm build-up. The build-up height was restricted by door thresholds and adjoining rooms, requiring accuracy across all 32m².
Pipework movement risk. Underfloor heating pipes can float or shift when screed is applied if not properly secured —extra clips were specified by us.
Our Solution
Accurate base preparation. We inspected the minor deviations in the insulation boards to create a solid, level platform for consistent screed depth.
Installed perimeter isolation. A full perimeter expansion strip was fitted to prevent thermal bridging and allow UFH expansion and contraction.
Specified Tarmac Tuff Screed. Tarmac Tuff Screed was selected for its:excellent early strength, reduced shrinkage, enhanced thermal conductivity,compatibility with wet UFH systems
Careful UFH pipe protection. Pipework was double-checked andsecurely clipped. Screed was placed carefully to avoid displacing pipes, working in controlled bays.
Quality-driven finishing. The screed was compacted, ruled off and trowelled to a smooth, UFH-ready finish that met the client’s levelling requirements.
Results
✅ 32m² of Tarmac Tuff Screed at 65mm installed cleanly and on schedule.
✅ BS8204 – Part1 level finish, ready for levelling compound (skim coat) and LVT.
✅ UFH pipework fully encapsulated (wetter mix) with ideal thermal mass for heat distribution.
✅ The installation achieved excellent SR levels, ensuring a premium result for follow-on trades.
✅ Client and contractor praised the speed, cleanliness, and accuracy of the installation.
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