Kenflex APP Waterproofing Membrane Mineral Grey 1m x 10m 4.5kg – Torch-On Roofing Felt
Kenflex APP Waterproofing Membrane – Mineral Grey Torch-On Roll
Heavy-duty, UV-resistant mineral-surfaced APP modified bitumen membrane for long-lasting waterproofing of flat roofs, concrete slabs, terraces and gutters in Nairobi and across Kenya.
Product Overview
The Kenflex APP Mineral Membrane is a premium torch-applied waterproofing sheet made from bitumen modified with Atactic Polypropylene (APP) and reinforced with a strong non-woven polyester core. Its top face is coated with grey mineral slate granules that protect the bitumen from the strong Kenyan sun, heavy rains and foot traffic, so the membrane can be left exposed as the final roof finish — no screed or paint needed.
The underside carries a thin burn-off polyethylene film that melts away under a gas torch, bonding the membrane fully to the primed concrete. The result is a seamless, flexible and fully waterproof layer that resists cracking, ponding water and temperature changes.
It is a trusted choice for contractors, fundis, engineers and homeowners waterproofing flat concrete roofs, balconies, podium decks, water tanks bases, box gutters and parapet walls. Available at Shabbiri Hardware — your waterproofing materials supplier on Magadi Road, Ongata Rongai and Tuala, Nairobi.
Technical Specifications
| Property | Specification |
|---|---|
| Brand | Kenflex |
| Product Type | APP (Atactic Polypropylene) modified bitumen membrane |
| Top Surface | Mineral slate granules – grey |
| Bottom Surface | Burn-off polyethylene (PE) film |
| Reinforcement | Non-woven polyester mat |
| Roll Width | 1 metre |
| Roll Length | 10 metres |
| Gross Coverage per Roll | 10 m² |
| Weight Grade | 4.5 kg/m² |
| Approximate Thickness | About 3.5 mm including granules |
| Softening Point (Ring & Ball) | Not less than 140 °C |
| Cold Flexibility | Down to −5 °C without cracking |
| Tensile Strength (Longitudinal / Transverse) | About 500 / 400 N per 5 cm |
| Elongation at Break | About 35 – 40 % |
| Watertightness | Watertight under 60 kPa water pressure |
| UV Resistance | Excellent – mineral layer shields the bitumen |
| Application Method | Torch-on (propane / LPG gas torch) |
| Recommended Primer | Bitumen primer, roughly 0.25 – 0.3 litres per m² |
| Side Lap / End Lap | 100 mm / 150 mm |
| Storage | Store rolls upright in a cool, dry, shaded place |
| Expected Service Life | 10 – 15 years with correct installation |
Performance figures are typical values for APP mineral membranes of this grade. Confirm project-critical values against the manufacturer's data sheet, available on request at any branch.
Key Features & Benefits
Sun & UV Shield
Grey mineral granules reflect heat and protect the bitumen, slowing ageing on exposed roofs.
Strong Polyester Core
High tear and puncture resistance that handles building movement and light foot traffic.
Heat Stable
APP bitumen stays firm on hot roofs and will not slide or flow in the dry season.
Fully Waterproof
Torch-welded seams form one continuous sheet that stops leaks and ponding seepage.
Finished Look
Neat grey surface needs no paint, screed or extra protective coating.
Fast to Install
Wide rolls lay quickly with a gas torch, cutting labour time on site.
Where to Use It
How to Apply APP Mineral Membrane
- Prepare the surfaceMake sure the concrete is fully cured, dry, clean and smooth. Remove dust, loose particles, oil and sharp projections. Fill cracks and form a 45° cement fillet (cant strip) where the slab meets walls and upstands.
- Check the fallsConfirm the roof slopes towards drains and outlets so water does not pond. Clear and fit all outlets before membrane work begins.
- Apply bitumen primerBrush or roll a coat of bitumen primer over the whole area, including upstands. Allow it to dry until touch-dry, usually a few hours depending on weather.
- Plan and dry-lay the rollsStart from the lowest point (near the drain) and work upwards so laps shed water. Unroll the membrane, align it, then roll it back up from both ends ready for torching.
- Torch the undersideUsing a propane or LPG torch, heat the underside film and the primed surface evenly until the film melts and the bitumen becomes glossy. Slowly unroll forward while pressing it down firmly.
- Seal the overlapsOverlap each new roll by 100 mm on the sides and 150 mm on the ends. On mineral sheets, warm the granules on the lap area and press them into the bitumen so the joint welds bitumen-to-bitumen. A small bead of bitumen should flow out along the edge.
- Stagger the end jointsOffset end laps of neighbouring rolls by at least 500 mm so joints never meet in a line.
- Detail upstands and outletsTurn the membrane up walls and parapets at least 150 mm above the finished roof level. Fix the top edge under a chase or termination bar and seal it with bitumen mastic. Dress the membrane into drain outlets carefully.
- Inspect and testCheck every lap with a trowel for gaps and re-torch any weak spots. Where possible, carry out a flood test before handing over the roof.
Safety & Good Practice
- Torch application should be done by trained, experienced applicators.
- Keep a fire extinguisher on the roof and never torch near flammable materials.
- Wear heat-resistant gloves, safety boots and eye protection.
- Do not install on wet surfaces or during rain.
- Avoid over-heating, which can burn the polyester core and weaken the sheet.
- Store and transport rolls upright to avoid flattening or sticking.
Frequently Asked Questions
What does 4.5kg mean on an APP mineral membrane?
It is the membrane weight per square metre. A heavier grade carries more bitumen and mineral granules, giving better durability on exposed roofs.
Can the mineral grey membrane be left exposed?
Yes. The mineral granule surface shields the bitumen from UV and weather, so it is designed as an exposed finishing layer.
How much area does one roll cover?
One roll covers ten square metres gross. After side and end overlaps, plan for roughly eight and a half to nine square metres of net coverage per roll, plus extra for upstands.
What is the difference between plain and mineral APP membrane?
Plain (sanded or film-faced) membrane is used as an under-layer or where it will be covered by screed or tiles. Mineral membrane has a granule top surface for exposed roofs that will not be covered.
Do I need primer before torching?
Yes. Bitumen primer seals the dusty concrete surface and helps the membrane bond fully. Shabbiri Hardware stocks bitumen primers and related waterproofing products.
Does Shabbiri Hardware install the membrane?
We are supply-only, but we can share contacts of independent waterproofing installers.
Visit Our Branches
Ongata Rongai Branch
Magadi Road, opposite Hashi Petrol Station, Ongata Rongai
Tuala Branch
Magadi Road, past Nazarene University, Tuala
Contact Shabbiri Hardware
Serving Nairobi, Ongata Rongai, Kiserian, Kitengela, Karen, Langata and all of Kenya since 1990. Supply-only — independent installer contacts available on request.
Specifications
| Category | Waterproofing & Sealants |
| Availability | In stock |
| Sourced by | Shabbiri Hardware Kenya Limited |
Customer reviews
No reviews yet — be the first to review this product.
Frequently bought together
Customers who bought this often add these to their order.
