Grant UK announced on 3 October 2022 that the Uflex and Uflex MINI Overlay System has joined its underfloor heating range1. The company describes the product as a dry, non-screeded system that can be laid on most types of new or existing floor surfaces, positioning it as a retrofit alternative to screeded underfloor heating1.
The system uses lightweight, high-density polystyrene boards, supplied in two thicknesses. The Uflex MINI boards are 16mm thick and take 10mm pipe at 100mm centres, while the Uflex boards are 20mm thick and take 16mm pipe at either 150mm or 200mm centres1. All boards are supplied in packs of ten1.
Each board is offered in two finishes. Non-foiled boards are designed for use with tiles where an adhesive is used, and foiled boards are designed for surfaces such as wood laminate1. The foiled boards carry a bonded layer of reflective 75micron aluminium foil on the upper surface, which Grant says enhances the rapid transmission of heat across the floor and offers an alternative to separate heat emission plates1. All boards have a reinforced cementitious layer, described as making them strong and impact resistant, and incorporate pre-formed grooves for the pipework1.
| Specification | Uflex MINI | Uflex |
|---|---|---|
| Board thickness | 16mm | 20mm |
| Pipe size | 10mm | 16mm |
| Pipe centres | 100mm | 150mm or 200mm |
| Finish options | Non-foiled or foiled | Non-foiled or foiled |
| Pack size | Ten boards | Ten boards |
Grant states that installation time is quicker because there is no need to wait several weeks for a wet screed to dry, and that disruption to existing floors is minimal because in most instances the system can be fitted directly on top of the floor surface1. The low profile of the boards means there is minimal increase to the height of existing flooring, and each board can be cut to suit room dimensions and pipework layout1.
"The addition of the Uflex and Uflex MINI Overlay System will give customers greater choice when it comes to installing an underfloor heating system, especially with retrofit projects. Installers can now opt to fit Grant's underfloor heating systems as a dry, non-screeded system which for certain types of projects, will be a beneficial alternative to traditional screeded systems."
Why it matters for households
Underfloor heating spreads heat across a floor surface rather than from a single radiator, and the way it is installed determines how disruptive the work is and how much floor height is lost. A screeded system involves wet screed that must dry over several weeks, which the company says the overlay boards avoid1. For a household, that bears on how long a room is out of use and whether the floor build-up can stay close to its existing level.
The board thicknesses and pipe sizes set out above also determine how much height is added and how much heat output a given floor area can carry, since closer pipe centres generally mean more pipe per square metre. Grant has not reported heat output figures, efficiency ratings or prices for either system, and no independent performance data is given in the announcement1. Whether an overlay system suits a particular home depends on the existing floor construction, insulation and the heat source it is paired with, none of which the announcement addresses.
Grant's wider underfloor heating range sits alongside its oil boiler products, and the principles of matching an emitter to a heat source and balancing the system apply to underfloor circuits as they do to radiators. Background on underfloor heating and on heating system design and balancing is available on this site.
What happens next
No installation dates, availability dates beyond the 3 October 2022 announcement, pricing or training details have been reported1.