Perfect for Smaller Roofs & Where Fast Application is Required

Sikalastic® Rapid-721 is a polymethyl methacrylate (PMMA), liquid applied roof waterproofing membrane, for use on flat roofs with limited access and gutters, where speed of application is a major advantage. The two component, solvent free, cold applied, liquid resin, cures following an extremely rapid in-situ polymerisation, which is activated by the addition of a peroxide catalyst. This curing proceeds rapidly even at temperatures around 0°C.


The membrane is reinforced with a polyester fleece and is installed wet-on-wet. This means that the polyester reinforcing fleece is first saturated with Sikalastic® Rapid-721 resin, bonding the membrane to the substrate, with the surface layer then applied onto the bonding coat whilst still wet, so forming a single seamless membrane of uniform thickness. The advantage of this type of application is that on smaller roofs a one day application may be possible, because there is no need to wait for drying between coats.

System Features

  • Rapid Curing - allowing areas to be treated quickly, minimising time on site
  • Wet on Wet Application - membrane and reinforcement applied in one operation, minimising time on site
  • Access Restrictions Minimised - as the materials achieve full mechanical properties exceptionally quickly
  • Cold Applied - eliminating the risk of fire on an occupied building during installation
  • Seamless - eliminating the possibility of joint failure through poor workmanship
  • Can Be Applied At Very Low Temperatures - with an ability to still achieve a rapid cure
  • Flexible - even at extreme sub-zero temperatures
  • Guarantee - 20 year guarantee available
  • BBA Accreditation (Certificate No: 16/5925)
Sikalastic® Rapid Roof Waterproofing System

System Build Up

  • Sikalastic® Rapid-721 and Sikalastic® Rapid Fleece 110
  • (Details areas) Sikalastic® Rapid-721 Thixo and Sikalastic® Rapid Fleece 110
  • Substrate*

*Prime as required

Guarantee Offering: Flat Roofing Systems


Gold Offer

(Material Guarantee & Final Inspection Certificate)


Silver Offer

(Material & Workmanship Guarantee)


Bronze Offer

(Material Guarantee)

Sikalastic® Rapid Roof Waterproofing

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