Owl Roof Lava 20 PU Mastic

A fast curing joint sealant, suitable as a general adhesive during application of the Owl Roof Lava20 system.
Available in 600cc Sausages
£10.08 £8.40
In stock
Product Description

Owl Roof Lava20 PU Mastic is a fast curing joint sealant, suitable as a general adhesive during application of the Owl Roof Lava20 system.

Best Uses

Owl PU Mastic is suitable for sealing joints in metal frames, aluminium windows and panels, glass, granite and marble or for flooring applications.

Owl Roof Lava20 PU Mastic is a fast curing joint sealant, general purpose adhesive that has been specifically formulated to contain both PU and silylated PU technology. Due to the nature of the sealant formulation, it includes the best properties of both technologies. The material has been modified in order to give enhanced thixotropic properties.

  • Excellent adhesion on almost any type of surface, with or without the use of special primers
  • Excellent extrusion, tooling and storage stability over wide range of climatic conditions
  • Excellent chemical resistance, suitable for sealing joints in swimming pools and chemically treated water
  • Micro-organism and fungus resistant
  • Application under water immersion possible
  • Excellent heat resistance, suitable for application where exposure to temperatures > 60°C take place
  • Resistance to cold: The sealant remains elastic even down to -40ºC.

Owl Roof Lava20 PU Mastic cures rapidly through reaction with atmospheric humidity to produce a sealant with excellent early grab adhesion even on substrates traditionally problematic for PU sealants, such as aluminum, steel, polycarbonate etc.

Additionally, the sealant has been modified in order to have extrusion profile identical to Hybrid PU or MS technology.


Clean joint thoroughly, and ensure that no oil, grease and wax contaminants, silicone remains are present. For many applications, primer is not required. In the case
of application on very porous substrates, bond area surfaces thoroughly to avoid the possibility of air bubbles being blown into the uncured sealant if the substrate temperature rises. The recommended primer is Owl Lava Prime.

Apply backing material such as open cell polyurethane or a closed cell polyethylene backing rod. Although both types of backing rod are recommended care must be taken when using the closed cell polyethylene rod that the outer skin not be punctured as in rising temperature conditions it may cause bubbling. Backing rod application is important as it ensures that the correct width to depth ratio is achieved provides a firm backing against which the sealant can be tooled off.

Slide the sealant into the applicator gun, cut off the very end of the sealant packaging and fit the gun with the nozzle that has been cut to deliver the right bead size.

Extrude the sealant into the joint ensuring that no air is trapped in the joint. Wide joints will require more than one pass of the application gun to make sure that sealant is in full contact with the sides and bottom of the joint. Tooling is recommended immediately after the application of sealant.

The ratio width to depth should be 2:1 subject to a minimum depth of 10mm.

Technical Details
  • Service Temperature: -4°C to 80°C
  • Hardness (ASTM D2240 / DIN 53505 / ISO R868: +/- 45 Shore A
  • Tack Free: 1.5 - 2.5 hours at 25°C
  • Cure Rate: 3 - 4mm per day
  • Coverage: 24 linear metres at 5x5mm (See data sheet for other width lines)
  • Shelf Life: 12 months minimum in the original packaging when stored in dry places and at temperatures of 5 - 25ºC. Once opened, use as soon as possible.
  • Available in 600cc sausages

The manufacturers data sheets are available for download from this website. It is your responsibility to read and understand all aspects of the data sheets before you place an order and prior to application. Please pay special attention to the preparation, mixing and application temperatures of the product, cleaning of substrate and environmental factors such as temperature, rain etc. Quoted coverage rates are based on the manufacturers theoretical rates and may vary depending upon substrates absorption, texture and application. We always recommend a test is carried out to ensure suitability.

Customer further agrees that Promain have no liability for any errors or omissions contained within the Product Data Sheets and are not liable for failure due to misapplication or inadequate substrate cleaning and preparation. For more information please refer to our Terms & Conditions.

Recommended products to use