The following installation instructions are to be used as a guide only. These should not replace the instructions from a suitably qualified engineer and any specific site specifications. You can learn more about the technical details of the Passive Foundation online or download the Design Guide.

  1. The site is prepared for the KORE Passive Foundation according to the instructions of a suitably qualified engineer. Typically, this includes clearing the topsoil and digging to a soil level that is free from vegetation.
  2. A minimum of 150mm 18-35mm stone is compacted into 50mm layers on the site. The thickness of the stone layer will depend on the site specific conditions. The stone can be compacted using a suitable roller or by compacting each layer with a 125kg plate compactor.
  3. Services should be considered at this point and a void formed in the stone to take services at a later stage.
  4. A 10-22mm layer of 804 concrete binding or equivalent is installed over the compacted stone. This binding layer must be leveled to a tolerance of +/- 2-3mm over the entire surface of the foundation.
  5. Starting at the highest point, at a corner point, in the case of a double L arrangement the outer EPS300 L piece is set in place. The corner pieces are cut on site to ensure a close butting of sheets at each corner. The EPS300 can easily be be cut to suit any angle required by the design. The entire outer L is placed in the foundation first, followed by the inner L.
  6. For services that need to penetrate the outer L, the EPS should be but before the concrete is poured to accommodate a void for fitting services at a later stage.
  7. Where there are internal load bearing walls a thickening of concrete 200mm - 300mm must be accommodated. Prior to fitting the floor insulation the space required for the internal load bearing walls is marked out. EPS300 in layers of 100mm or 200mm will be required under the load bearing walls.
  8. Following the placement of the perimeter EPS300 detail, the first 100mm layer of KORE Floor EPS100 White and KORE EPS300 Sheets (for the load bearing walls) are put in place starting from the perimeter inwards until the entire foundation is covered in insulation.
  9. KORE Floor Insulation System should be laid with closely butted joints, laid staggered with a break-bonded pattern and fitted tightly at the edges.
  10. The DPC/radon barrier is placed over the first layer of insulation and runs over the L detail and out.
  11. The second and third layer of KORE Floor EPS100 White are placed over the DPC/radon barrier.
  12. Where appropriate a second 100mm layer of EPS300 should be placed at the load bearing walls.
  13. Steel reinforcement to the specification of a suitably qualified engineer is now put in place and tied in the appropriate manner. Reinforcing bars are used in the outer ring beam and at internal load bearing walls. A steel mesh is used on the concrete slab.
  14. When fitting the underfloor heating pipes, the pipes can be clipped to the steel mesh or to the KORE Floor Insulation.
  15. The perimeter of the KORE Passive Foundation must be braced appropriately for the concrete pour to avoid the EPS from moving from the pressure of the concrete. Typically this can be achieved by clipping the perimeter strips together using U shaped steel clips, by using timber bracing fixed to the outside of the L piece or by back filling the outer L with 18mm-35mm stone.
  16. 25 to 30 N concrete (this specification will vary depending on the requirements of the engineer) is poured into the ringbeam and slab in one pour. The concrete is vibrated to ensure appropriate steel/concrete coverage.
  17. Care should be taken to avoid damage to the insulation or DPM and radon barriers as the slab is being poured and operatives should make use of barrow runs and walkways whilst installation progresses.
  18. Airtightness details between the floor and the wall structure must be considered and best practice adopted.
  • Passive Foundation Step 1
  • Passive Foundation Step 2
  • Passive Foundation Step 3
  • Passive Foundation Step 4
  • Passive Foundation Step 5
  • Passive Foundation Step 6
  • Passive Foundation Step 7
  • Passive Foundation Step 8

Request a Quotation for the KORE Passive Foundation

Request a Quotation