FORZAFLEX MINERALE 4.5 Torch-on cap sheet
Torch-applied APP-modified bitumen mineral cap sheet, UV exposed
UV-exposed Class I mineral cap sheet. The slate surface is the finished roof, no topcoat.
FORZAFLEX MINERALE 4.5 sizes and key figures
Final, permanently exposed layer of a multi-layer torch-applied system for roofs, balconies, podiums and retaining walls. For maintenance access only, not a trafficable surface.
- Class
- Class IAS 4654.1 incl. UV exposure, Report 596-1 · TDS p2
- UV elongation
- 25%control 40%, pass requirement 16% or more · TDS p4
- Roll size
- 10 m × 1 m10 m² gross, approx. 9.1 m² effective after laps · TDS p3
- Thickness
- 4.0 mmtypicalnominal, R&D to EN 1849-1. Mass is 4.5 kg/m² · TDS p3
- Seam strength
- 279.20 N/25 mmfield seam, AMTM005, Report 596-1 · TDS p3
- Abrasion
- 0.045 mmnon-trafficable test, limit 0.2 mm, Report 596-1 · TDS p2
- Laps
- 75 / 150 mmside lap at granule-free selvedge / end lap · TDS p4
- Apply at
- 5°C to 40°Ctypicalambient. No torching in rain, wet or high wind · TDS p4
- Flood test
- 50 mm, 24 hafter all laps and detailing, before return to service · TDS p7
From the FORSPEC data sheet, TDS-FORZAMIN45 · Revision 2 · 12 November 2026. Times are at 25°C and 50% relative humidity unless the data sheet says otherwise. Typical = FORSPEC’s own typical value, not a laboratory-certified one.
Where FORZAFLEX MINERALE 4.5 is used
Use it for
- Exposed roof waterproofing, final layer of a torch-applied system
- Balconies and terraces where the membrane stays the finished surface
- Podium slabs and plaza decks
- Retaining walls, exposed or protected
- Plant decks and roof areas with maintenance access only
- Re-covering sound torch-applied systems, subject to assessment
Know before you start
- Not trafficable: abrasion 0.509 mm against a 0.2 mm limit, maintenance access only
- Do not coat, paint or cover the mineral surface unless the system design says so
- No torching direct to combustible substrates, or onto wet, damp or green surfaces
- Class I only: use a higher-class membrane where Class II or III is needed
Its FORSPEC systems
How to apply FORZAFLEX MINERALE 4.5
- 01
Prepare
Concrete cured 28 days minimum, Concrete Surface Profile 3–6, dry and free of laitance and contaminants. Falls at least 1:100 to outlets. Repair defects with FORBUILD 100 or FORCRETE 100.
- 02
Prime
Where the cap sheet goes direct to concrete, masonry or metal rather than over a FORZAFLEX BASE 3mm ply, apply FORZAPRIME and let it dry tack-free.
- 03
Lay out
Start at the lowest point. Side laps 75 mm at the granule-free selvedge, end laps 150 mm, staggered at least 1 m. Offset cap laps from the base laps beneath.
- 04
Torch
Heat the underside film until molten and roll steadily, with 6 to 12 mm of molten flow ahead of the roll. At end laps embed or remove loose granules so bitumen fuses to bitumen. Do not overheat.
- 05
Inspect
Cool about 30 minutes, then probe every lap and check for blisters. Make good any granule loss so no bitumen is left exposed to UV.
- 06
Test
Flood to at least 50 mm for 24 hours once all laps and detailing are inspected, before the area returns to service. Provide walkway protection on access routes.
A short guide from the data sheet. Read the full FORZAFLEX MINERALE 4.5 TDS before you start.
Drawings for the systems it goes in
FORSPEC standard details as PDF and DXF. Each sheet is a generic detail: the specification names the products.
FORZAFLEX MINERALE 4.5 test reports and compliance
- AS 4654.1-2012
- Class I (low extensibility), all durability criteria incl. UV: passNATA Report 596-1
- AS 4654.1 Appendix B
- Pass, 50 cycles, no rupture, crazing or tearsNATA Report 596-1
- AS 1580.403.2, non-trafficable
- 0.045 mm, meets the 0.2 mm limitReport 596-1
- AS 1580.403.2, trafficable
- 0.509 mm, does not meet the trafficable requirementReport 596-1
- ASTM E96
- 0.02 g/m²/24 h water vapour transmissionReport 596-1
- ASTM D6207
- No changes observed over two full cyclesReport 596-1
Download the reports
Results as stated in the data sheet, TDS-FORZAMIN45 · Revision 2 · 12 November 2026. Warranty up to 25 years, depending on the system: ask FORSPEC which term applies to your system.
FORZAFLEX MINERALE 4.5 questions
Can I walk on FORZAFLEX MINERALE 4.5?
For maintenance access only. It is not a trafficable membrane: abrasion was 0.509 mm against a 0.2 mm limit. Provide walkway protection on access routes and a separate wearing surface where traffic is needed.
Do I need to coat or paint the surface?
No. The mineral slate gives permanent UV protection. Do not coat, paint or cover it unless the system design specifies it, as coating defeats the UV protection and can trap moisture.
How many rolls do I need for 100 m²?
About 11. Each 10 m × 1 m roll gives approx. 9.1 m² after laps. Allow at least 10% extra. Where a BASE 3mm ply goes beneath, allow the same quantity again.
Does it need a base ply?
It is the cap sheet of a multi-layer system, with FORZAFLEX BASE 3mm as the base or intermediate ply beneath. Where it goes direct to the substrate, prime with FORZAPRIME.
What do I use in planter boxes?
FORZAFLEX RR, the root-resistant cap sheet, is used in place of MINERALE 4.5 in planter boxes, green roofs and landscaped areas.
How are the laps formed?
Side laps are at least 75 mm, fused at the granule-free selvedge. End laps are at least 150 mm, with granules embedded or removed so bitumen fuses to bitumen.
Used with FORZAFLEX MINERALE 4.5
FORZAFLEX MINERALE 4.5 TDS and SDS
Always work from the current data sheet. Every FORSPEC TDS and SDS →
Specify it. Or buy it.
Send the drawings or photos and FORSPEC comes back with the system, the details and the quantities. Or find a FORSPEC stockist for FORZAFLEX MINERALE 4.5.