Water underfloor heating for new screeded floors, with grip rails that guide regular rows of pipe.
AD-RAIL holds heating pipe in place over rigid insulation, making it easier to follow the planned layout. The screed then surrounds the pipe to distribute heat beneath the finished floor.
2Prepare the base and fit the specified rigid insulation and perimeter edge insulation.
3Fit any membrane required by the floor specification.
4Set out and secure the rails using the approved adhesive or fixing method.
5Press the pipe into the rails at the designed spacing and connect each circuit.
6Fill and pressure-test the circuits before screeding.
7Lay and cure the screed, then commission the system to the current instructions.
Choosing your fixing method
AD-RAIL or AD-CLIP?
Both systems hold heating pipe in place before screeding. Choose AD-RAIL for regular room layouts where grip rails help guide repeated rows. Compare AD-CLIP for individual fixings that follow bends, obstacles and irregular routes.
Set out the rails first to guide the planned pipe rows.
Press the pipe into the rail positions specified by the design.
Use rail sections to reduce individually placed fixings along straight runs.
Inspect the complete pipe layout before it is covered by screed.
Plan the complete installation
Where AD-RAIL Works Best
Consider AD-RAIL when the project allows for insulation and a new screed, with a room layout that suits regular pipe rows.
New builds and extensions with a new screeded floor.
Major renovations where the floor is being rebuilt.
Suitable solid or beam-and-block floors.
Larger or regular rooms where rail-guided rows simplify setting out.
Typical AD-RAIL Floor Build-Up
From the structural floor upwards, a typical build-up includes the layers below. The exact specification depends on your project.
1Prepared structural floor
2Specified damp-proofing or membrane, where required
3Rigid floor insulation, with perimeter edge insulation
416mm heating pipe held by AD-RAIL grip rails
5Specified pumped or sand-and-cement screed
6Compatible floor finish with the required adhesive or underlay
16mm
PERT-AL-PERT heating pipe
200mm
Designed pipe centres
50mm
Typical pumped-screed minimum
65mm
Typical sand/cement minimum
AD-RAIL project advice
Frequently Asked Questions
Clear answers about grip rails, pipe spacing, screed depths and planning an AD-RAIL installation.
What is the AD-RAIL system?
AD-RAIL is an in-screed warm-water underfloor heating system that uses grip rails to position 16mm PERT-AL-PERT pipe over rigid insulation before the screed is installed.
How is AD-RAIL different from AD-CLIP?
AD-RAIL holds pipe in grip rails that guide regular rows. AD-CLIP uses individual tacker clips, making it easy to follow bends and irregular routes. The heat output of either system depends on the heating design and complete floor build-up.
What pipe spacing is AD-RAIL designed around?
The current AD-RAIL kit specification is designed around 200mm pipe centres. The final layout must follow the heat-loss and circuit design for the project.
What screed depth is required?
Current system guidance states typical minimum depths of 50mm for a suitable pumped screed or 65mm for a sand-and-cement screed. The screed manufacturer and project designer must confirm the actual depth and construction.
View all AD-RAIL questionsShow fewer questions
Can AD-RAIL be used over beam-and-block floors?
Yes, it can be considered within a correctly designed beam-and-block floor build-up using the specified preparation, insulation, membrane where required and screed construction.
Does AD-RAIL require insulation?
The system is normally installed over rigid PIR insulation. The required thickness and thermal performance depend on the floor construction, building regulations and project design.
Can AD-RAIL form a multi-zone system?
Yes. Multiple circuits and room zones can be designed around an appropriately sized manifold and compatible controls. Off-the-shelf kit options still need checking against the required zoning arrangement.
How do I choose the correct AD-RAIL kit?
Start with the heated area, room layout, floor construction, heat source and number of zones. The design should confirm pipe quantities, circuit lengths, manifold ports and controls.
