Product Data Sheet Show all documents

SikaRoof® Liquid Membrane

A ready to use, polyurethane liquid waterproofing membrane for roofs

SikaRoof® Liquid Membrane is a cold-applied, one-component polyurethane waterproofing system. It forms a seamless, permanently flexible membrane that protects against water ingress. SikaRoof® Liquid Membrane becomes shower resistant in just 10 minutes and cures reliably across a wide range of weather conditions.  Suitable for flat and pitched roofs, SikaRoof® Liquid Membrane has excellent adhesion to both porous and non-porous substrates and is suitable for use on new projects, extensions or to refurbish an existing leaky roof.

  • Suitable for use with both new and old roofs.
  • Moisture curing technology – no catalyst required.
  • Fast curing – rain resistant after 10 minutes.
  • All weather product.
  • Ready to use – apply with brush or roller.
  • Forms a seamless membrane.
  • Can be reinforced with Sikalastic® Fleece-120.
  • Easily recoated, no stripping required. Provides cost effective life-cycle extension of failing roofs.
  • Vapour permeable – allows substrate to breathe.
  • Elastic – retains flexibility even at low temperatures.
Seek a Stockist Contact Us
Product Data Sheet Show all documents

Usage

  • Waterproofing flat and pitched roof structures.
  • Suitable for new roofs as well as the refurbishment of existing structures.
  • Suitable for use on: mortar, brick, stone, fibre cement, roof tiles, asphalt and bituminous coatings.
 

Advantages

  • Suitable for use with both new and old roofs.
  • Moisture curing technology – no catalyst required.
  • Fast curing – rain resistant after 10 minutes.
  • All weather product.
  • Ready to use – apply with brush or roller.
  • Forms a seamless membrane.
  • Can be reinforced with Sikalastic® Fleece-120.
  • Easily recoated, no stripping required. Provides cost effective life-cycle extension of failing roofs.
  • Vapour permeable – allows substrate to breathe.
  • Elastic – retains flexibility even at low temperatures.

Packaging

7 kg and 21 kg metal tins

Colour

Slate Grey

Product Details

Product Information

Shelf Life

12 months from date of manufacture in unopened containers

Storage Conditions

Store upright in original packaging. Keep in a dry, well-ventilated area at 0 °C to +25 °C. Protect from sunlight and frost. Storage temperatures above +25 °C may reduce shelf life.

Density

~1.42 kg/L

Solid content by mass

~80 %
Technical Information

Tensile Strength

Unreinforced with matting: ~4.5 N/mm2 

Reinforced with matting: ~8 N/mm2 (ISO 527-3)

External Fire Performance

Broof (t1)

Reaction to Fire

Euroclass E

Application

Application Information

Surface temperature

Substrate temperature must be between +5 °C and +60 °C. Moisture content of substrate must be ≤4 %
Application steps

SUBSTRATE PREPARATION

Ensure substrate is in good condition e.g. cracks sealed, sound joints, tiles securely fastened etc. All timbers used in roof constructions must be suitable for exterior use. Adhere to good building practices in the selection of building materials and design of roof constructions. Make sure any gaps are filled with an appropriate seal.

APPLICATION

SikaRoof® Liquid Membrane can be applied using a soft bristle brush or a solvent resistant roller. If product has settled or separated on opening, stir gently in order to achieve a uniform colour. Do not overmix as this will cause air entrainment. Generally priming is not required (see limitations); for porous or irregular surfaces apply an additional priming coat of 0.25-0.3 L/m². Ensure all surfaces are sound, clean and free from dust and loose friable material prior to application. Protect handrails etc. with tape and/or plastic wrapping prior to application. Roof coatings – At least two coats of 1 mm depth are needed. Allow for the first coat to dry before applying the second coat (6 hours at +20 °C).

Ambient Conditions Minimum Time Between Coats^
+5 °C/ 50 % r.h.Allow overnight curing
+10 °C/ 50 % r.h.12 hours
+20 °C/ 50 % r.h.6 hours
+30 °C/ 50 % r.h.4 hours

^If time between coats is longer than 4 days, clean surface and apply reactivation primer before applying second coat.

Documents

FAQ

How do I apply SikaRoof® Liquid Membrane?

Use a soft-bristle brush or solvent-resistant roller. Apply two coats at roughly 1mm each, letting the first coat dry before the second.

How do I clean tools or spills?

Clean tools immediately with xylene. Once cured, removal is mechanical only. For hands / skin, use soap and water or Sika® Wonder Wipes.

What roof surfaces can I use SikaRoof® Liquid Membrane on?

Works on mortar, brick, stone, metal, wood, tiles, roofing felt and asphalt
(soft/bituminous surfaces may need reinforcement).

How durable and flexible is SikaRoof® Liquid Membrane?

SikaRoof® Liquid Membrane forms a fully bonded, seamless waterproof layer that moves with the roof rather than cracking. It has high elasticity, meaning it can stretch and recover with building movement or temperature changes without losing adhesion. Once cured, it is UV and weather-resistant, providing long-term protection against rain, sunlight, and temperature extremes.

Can I use SikaRoof® Liquid Membrane in cold or damp conditions?

Yes. Apply when air temps are roughly +5 °C to +40 °C and the substrate is +5 °C to +60 °C with low moisture (≤ 4%).

How quickly does SikaRoof® Liquid Membrane become rain-resistant?

It becomes rain-resistant in around 10 minutes after application - handy for changeable UK weather.

Do I need reinforcement?

On simple, solid substrates you may not. For felt, asphalt or soft/irregular
areas, use reinforcement fleece such as Sikalastic® Fleece-120 at details and
stress points.

What prep do I need before applying SikaRoof® Liquid Membrane?

Make sure the surface is sound, clean, dry, and free of dust or loose material. Fix cracks first. On very porous or uneven areas, apply a primer coat before the main coats.

What is SikaRoof® Liquid Membrane used for?

It’s a ready-to-use, all-weather, polyurethane-based liquid waterproofing membrane for flat and pitched roofs, ideal for refurbishments and new roofs.