APP modified torch applied waterproofing membrane


POLYPLUS P 4180 modified bitumen membranes are plastomeric waterproofing membranes, manufactured from a rich mixture of bitumen and selected polymers blended together to obtain good heat and waterproofing properties. The polymerized bitumen is coated on to a dimensionally stable reinforcement core of non woven spun bond polyester fabric to obtain good tensile & tear strengths and puncture resistance.


  • High resistance to positive water & vapor pressure 
  • Good dimensional stability under tension 
  • Good flexibility. Can accommodate structural movements 
  • Resists water borne chemicals 
  • High heat resistance

This TDS is applicable for the United Arab Emirates only. Please contact your local Polybit sales office for the available TDS in your region

Step by step

Application procedures may vary slightly depending upon site conditions. However below given are the general guidelines for the application of the waterproofing system:


The surface should be free from dust, dirt, curing compound, oil etc. Clean the surface thoroughly to remove all loosely adhering particles and cement laitance. All surface imperfections and protrusions are to be removed and repaired. Structurally unsound and friable concrete must be removed and repaired with a suitable repair mortar.


Apply POLYPRIME SB @ 4-6 m²/lt. as per ASTM D 41 to a clean smooth and dry surface by brush, roller or spray. Refer primer data sheet for more details. Allow the primer to dry prior to the application of the membrane.


Unroll and align POLYPLUS P 4180 rolls and re-roll correctly before torching. Side and end overlaps should be a minimum of 100 mm. Torching Use a gas torch to heat the substrate and the underside of POLYPLUS P 4180. When the embossing on the membranes starts to disappears during torching the membrane is ready to adhere. Roll forward and press firmly with a roller against the substrate to bond well.
Caution: Do not over torch as this will expose the reinforcement in the membrane and cause damage to it.


Heat both the overlaps and use round tipped trowel to seal the overlap. Excess compound should be smoothed and pressed into the seam using a heated trowel.


All angles and abutments should be sealed with extra care to ensure full bonding. Seal the edges well into the grooves and protect with POLYSEAL PS or suitable mastic sealant.