Clip Rail

Polypipe also offers a Clip Rail system that fits directly onto the insulation layer that is laid before a screed or concrete floor is installed. This is a more traditional method of installing underfloor heating into a Solid/Screeded floor.


Features & Benefits of using the Clip Rail system:

  • Provides a guide for pipe spacing
  • Can be fixed directly to insulation
Material Requirements (Approx.)
Pipe 4.5m/m² at 200mm Centres
3.3m/m² at 300mm Centres*
(*18mm pipe only)
Clip Rail usage 1 x 1m rail/1m² of floor area
Fixings 1 x bag (250 per 50m² floor area)
Edge expansion strip 1.1m/m²
Conduit pipe 2m/circuit
Product dimensions 1m lengths
Clip Rail installation guidance
  • Step 1: Fitting Insulation

    In accordance with Part ‘L’ of the current Building Regulations, a suitable layer of insulation material should be included within the floor construction. It is the responsibility of the architect or builder to ensure compliance. However, in all instances insulation must be installed beneath the underfloor heating system in order to ensure that any downward heat loss does not exceed 10W/m2, in accordance with BS EN 1264.

  • Step 2: Laying the insulation panels

    When laying the insulation boards, ensure that the joints of each board are staggered and securely taped so as to minimise any risk of movement.

  • Step 3: Fitting the edging strip

    Using the edge expansion strip allows the free expansion of the floor screed. The expansion strip comes with a self-adhesive strip which bonds the panel to the wall, it should be installed around the perimeter wall and around fixed constructions such as columns, steps and access doors. The edge expansion strip also comes with a plastic skirt which lays over the top of the insulation to prevent the screed seeping in to the join between the insulation panel and edge expansion strip. Edge expansion strip should be fitted in addition to perimeter insulation required by Building Regulations.

  • Step 4: Fitting the clip rails

    Secure the clip rails to the insulation board by using the clips (PB02911). Firmly push the clips downwards into the insulation at 200mm centres so as to ensure that the clip rail is fully secured and lays at to the insulation.

    Continue to fit the clip rail across the room at 1m intervals making sure that sufficient space is left around the perimeters of the room (approx. 800mm) so to accommodate any pipe returns or connection lengths back to the manifold. Care should also be taken to ensure that the clipping alignment is maintained.

    It is not necessary to overlap the clip rails. They can be clipped together end to end to form longer lengths.

  • Step 5: Laying the pipe

    Fit the pipe into the clip rails at 200mm centres in a serpentine pattern and then bend the pipe at 180° at the end of each circuit ensuring that the edge of the bend is parallel with the adjacent circuit.

    Continue to lay the pipe in this serpentine pattern until you have reached the end of the circuit.

  • Step 5: Fixing the pipe

    Continue to fix the pipe down using the pipe staples as you exit the pipe from the circuit. The plastic skirt should be laid over the insulation and the outside run of pipe stapled into the skirt covered insulation to create a seal around the edge of the area.

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