Drainage Protection and Insulation Board (DPI) is manufactured using expandable polystyrene (EPS) and can be manufactured in various densities and thickness depending on the nature of the application.

The board has numerous features and may be utilized in various applications in a number of different markets. The material is versatile, cost effective, friendly to the environment and unique in all installations. The use of a woven polypropelene in conjunction with DPI board is essential to the success of the system.

Design Features:

  • improves waterproofing
  • protection against damage to waterproofing system
  • alleviates water pressure and hydrostatic pressure build up
  • excellent compressive strength ( 40 - 50 DV), ensures equal transfer of load without damage
  • highly effective drainage layer
  • ease of application, lightweight and no mechanical fixings required (water based adhesive)
  • chemical resistance to most acids, alkalis, bacteria and micro organisms
  • anti root (if required)
  • non perishable
  • economical
  • ship lap jointed
  • environmentally friendly


Inverted Roofing Systems

Waterproofing installed to falls. Drainage Protection and Insulation (DPI) board installed with the drainage channels in either direction to allow for efficient water flow to the outlets as well as the most effective polystyrene insulation due to the entrapped air voids within the system. Woven Polypropelene geotextile installed over DPI to allow dust and fines to drain effectively without clogging (as occurs with non woven geotextiles). Install 19mm clean washed aggregate, (approximately 50mm thick) and paving stones in walkway areas to allow maintenance crews access to plant and equipment.

(Refer to CSIR & SABS test reports for drainage capacity and insulation values)

No maintenance to the waterproofing system is required.

Protection of Waterproofing Membranes (vertically & horizontally)

As in, inverted roofing system installations it is essential that the waterproofing system be protected against damage by other sub-trades. Planter applications, protection is as essential during the installation of soil and plants. Vertical tanking of basement walls whilst backfilling. During construction damages occur on a regular basis, this can be avoided with the use of DPI Board.

Drainage mediums:


Drainage Protection & Insulation is installed to allow for effective control of water flow, protection against root penetration & mechanical damage.

Roof Gardens:

DPI Board allows for effective drainage of water through soil which prevents rotting and decomposing of plants, ground covers, lawns and other horticultural applications. Prevents root penetration into waterproofing membranes enhancing the life expectancy of waterproofing membranes.

Retaining Walls:

DPI Board is unique in that it allows for effective protection, drainage and prevents hydrostatic build up by draining and deflecting water into sub surface agricultural drains and sumps.


Detailed specifications can be supplied on request.


Refer to Health and Safety Specifications for the use of Polystyrene Materials.

conrete roofs

(1.1) Insulation of concrete roofs

DPI landscape

(1.2) Drainage and protection of waterproofing in landscape area's


(1.3) Vertical retaining walls

"Dynamic, Inovative, Ecological and Professional."