FAQ's
Surface-Specific Guidelines
Felt surfaces require matting reinforcement for durability. Clean and dry the surface, apply the first coat of Lava 20 while embedding polyester or chopped strand matting, then apply the second coat. Pay attention to overlaps and edges.
Felt: Yes. Matting is recommended for added strength and movement tolerance.
PVC: Matting is typically required unless bridging joints or detailing corners. Always use Lava 20 PVC Primer before coating.
Use brushes, squeegees, and rollers (preferably short & medium-pile, solvent resistant) depending on the surface and detail. For corners, joints, and tricky areas, brushes provide better control.
Yes, Lava 20 has self-levelling properties, allowing smooth finishes over flat horizontal surfaces. Naturally it is not self-levelling on vertical surfaces. However, we have a thickened version of Lava 20 called Lava 20 Vertical for sloped or vertical surfaces.
Yes, Lava 20 is designed to be applied over both new and existing surfaces, including previously coated roofs and balconies. The key is proper surface preparation—cleaning, priming, and ensuring the substrate is sound and free from loose material. Lava 20 adheres to most substrates, including felt, asphalt, concrete, timber, metals, PVC, and more.
Product Variants & Detailing
• Lava 20: Main waterproofing membrane for flat surfaces.
• Lava Detail 20: Fiber-reinforced variant used in complex areas like joints, seams, and corners.
• Lava 20 Vertical: Thixotropic formula that prevents dripping, ideal for vertical & sloped surfaces like upstands, parapets, or 90°/180° angles.
There are two recommended methods for waterproofing vertical areas such as upstands:
- Lava 20 System with Reinforcement:
- Apply Lava 20, embed Polyester Tape or Mesh Fleece (wet-on-wet), then apply a second coat of Lava 20 over it.
- This method provides a reinforced, durable waterproofing layer even on vertical or angled surfaces.
- Lava 20 Vertical:
- Use Lava 20 Vertical, a semi-thixotropic formula specifically designed to hold on vertical surfaces without dripping or sagging. Ideal for 90° and 180° angles and complex geometries.
Both systems are effective. Choose based on site conditions, complexity, and installer preference.
Reinforce with matting and follow the full application build-up: primer, first coat + embedded matting + second coat of Lava 20 and top coat (optional but preferred). Ensure slope and drainage are adequate.
Yes, all reinforcement options offered with the Lava 20 System are flexible and suitable for a variety of detailing needs. Here’s a breakdown:
- Polyester Tapes / Fabrics:
- Highly flexible and easy to work with.
- Ideal for corners, joints, and complex detailing where adaptability is crucial.
- Chopped Strand Matting (Powder Bound):
- Yes, it’s flexible but breaks down.
- Excellent for flat and irregular surfaces, corners, and curved areas.
- Becomes mouldable, providing a snug fit around uneven detail.
- Chopped Strand Matting (Emulsion Bound):
- Also flexible but does not break down like powder-bound versions.
- Best suited for flat, open surfaces where a more stable reinforcement layer is needed.
Each option has its own application advantage, depending on the surface type and detailing requirement. Always select the right reinforcement material based on the project specification.
Allow to dry, cut out the bubbled area, sand it smooth, then re-apply Lava 20 over it, following the same build-up as the surrounding area. See how to avoid bubbles on application guideline (p.17) (link: https://owl-waterproofing.paperturn-view.com/eu-lava-20-application-guide-surfaces-1?pid=ODg8882364&v=2&source=qr&p=18)
Specialized Areas
Yes, Lava 20 is suitable for use on gutters, valleys, internal corners, edge trims, and other drainage features. It forms a seamless, durable membrane.
Important preparation notes:
- If the gutter or valley surface is metal and rusted, treat the rust first using a wire brush and apply a rust inhibitor like Owatrol Oil. Allow it to dry completely.
- Then follow the Lava 20 application guideline, ensuring to reinforce joints, laps, and detailed areas (like valleys and outlets) using polyester tape or chopped strand matting.
For vertical or tight angles, you may also use Lava 20 Vertical to avoid sagging or dripping.
Lava 20 is a Polyurethane based liquid rubber waterproofing system offering longer life, superior adhesion, and stronger waterproofing than other systems available on the market, which may peel or fail in ponding situations. Lava 20 system is more durable, versatile and has a longer warranty than other systems.
Use Owl PU Mastic for sealing penetrations, outlets, and edge trims before applying Lava 20 and fleece.
Pre-seal with PU Mastic, then use Lava Detail 20 or Lava 20 with embedded matting for a watertight finish.
Wire brush the rust, clean the area, and apply a rust inhibitor like Owatrol Oil or similar. Once dry, follow the full Lava 20 system with appropriate primer and membrane.
Grind rust off and treat with rust inhibitor like Owatrol Oil or similar first, let it cure, then follow with primer and Lava 20 build-up as normal.
Technical & Product Care
No, not if applied correctly. Peeling can occur only if the surface was not properly cleaned, primed, or if curing was interrupted by rain or contaminants.
Use tape on all joints, cracks, overlaps, seams, and weak areas.
Width typically depends on the gap and detailing area size. We have 4 inch, 6 inch, 8 inch and 1 meter wide tape available.
Catalyst ratio for fastest cure:
- Lava 20 (6 kg): Use 0.18 kg of catalyst
- Lava 20 (15 kg): Use 0.45 kg of catalyst
- Lava 20 (25 kg): Use 0.75 kg of catalyst
If you use full catalyst, you can apply a maximum of 3 mm thick coating in a single coat and it will cure within 2 to 5 hours.
If no catalyst is used, you can apply a maximum of 0.9 mm in one coat and it will dry over 7 to 10 hours.
For more check the application guideline (link: https://owl-waterproofing.paperturn-view.com/eu-lava-20-application-guide-surfaces-1?pid=ODg8882364&v=2&source=qr&p=19)
Ideally try to use open cans on the day of opening. If no catalyst was used you can place cling film over the opening, reseal the lid tightly, and store the can upside down to minimize air contact.
Yes. Lava 20 is suitable for wet rooms, bathrooms, and shower areas, provided it’s applied over a fully primed and properly prepared surface.
Do not forget to use adequate PPE & ventilation on interior applications.
Order Information
Ordering Lava 20 Kits is simple and convenient:
- For EU & UK customers: Visit our full Lava 20 Kits range (link)
- Not sure which kit you need? Use our Roofing Calculator (link) to find the right coverage and kit size.
- To locate your nearest distributor or stockist, visit our Contact Us (link)
- For USA enquiries:
Visit owlwaterproofing.com
- Browse our full library of Technical Documents (link) for datasheets, certifications, and application guides.
- Contact our Technical Sales Department at:
info@lava20waterproofing.com - Reach out to your local distributor or stockist for personalized technical advice.
Lava 20 is a next-generation waterproofing system trusted by professionals across worldwide. Here’s why:
- 25-Year Warranty – Long-lasting protection backed by testing and performance.
- Fast & Easy Application – Apply wet-on-wet with minimal downtime.
- All-Weather Performance – UV-stable, frost-resistant, and heat-resistant.
- Certified System – BBA, CE, Miami-Dade, and Fire Rated.
- Ideal for Flat Roofs, Gutters & Details – With specialized products for verticals and joints.
- No Peeling or Cracking – Fully bonded, breathable, and flexible.
- Eco-Conscious & Safe – Low-VOC formula and cold-applied without flames.
Lava 20 gives you professional-grade performance with the simplicity of a kit-based solution.
Yes, Lava 20 is readily available in the UK through our direct website and national distributor network. Visit our Contact Us page to find your nearest supplier or you can order online here.
Yes, Lava 20 is available in the United States. Visit www.owlwaterproofing.com to enquire, order, or find your nearest stockist.
Yes, Lava 20 is backed by a 25-Year Warranty when installed as per the official application guidelines and with full system components. This warranty reflects its proven durability and long-term performance.
Yes, Lava 20 carries leading international certifications, including:
- BBA (British Board of Agrément)
- CE Marking (European Compliance)
- Miami-Dade County Product Approval (USA)
- Fire Rating: B ROOF (t4)
For downloadable certificates and datasheets, visit our Technical Info (link) page.
