ACTFLEX 901 BUV Exposed bitumen membrane
One-component water-based modified bitumen emulsion waterproofing membrane
Stays exposed and walkable: no screed, tiles or protection layer. Ready to use from the pail.
ACTFLEX 901 BUV coverage, coats and cure times
One-component water-based membrane for exposed concrete roofs, trafficable terraces, sloped roofs and gutters. It also refurbishes old asphalt and bituminous sheet and details FORZAFLEX sheet systems.
- Coverage
- 5.1–6.8 m²practical, per 18 kg pail at 1.5 mm DFT · TDS p5
- Dry film
- 1.5 mm2 coats of 0.75 mm, second at right angles · TDS p5
- Consumption
- 2.4–3.0 kg/m²total for two coats · TDS p5
- Recoat
- 8–48 hminimum 8 hours, maximum 48 hours · TDS p5
- Hard dry
- ≈ 7 htypicalat 1.5 mm DFT; surface dry about 3.5 hours · TDS p6
- Foot traffic
- 7 dayslight pedestrian, after the final coat · TDS p6
- Full cure
- 7 daysafter the final coat · TDS p6
- Pack
- 18 kg pailgrey-brown, ready to use · TDS p2
- Apply at
- 5–35°Cambient and substrate · TDS p2
From the FORSPEC data sheet, TDS-901BUV · Revision 1 · 3 September 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 ACTFLEX 901 BUV is used
Use it for
- Exposed concrete roofs and roof slabs
- Trafficable terraces and walkable exposed decks
- Sloped roofs and eaves gutter lines
- Refurbishing existing asphalt and bituminous sheet membranes
- Termination and detailing for the FORZAFLEX sheet range
- Sealing sheet edges, mechanically fastened and ballasted
Know before you start
- Not compatible with polyurethane: never use ACTFLEX 929 SL, 929 HV, 75FC or MS PRO
- Not for permanent immersion, tanks, pools or water-retaining structures
- Pedestrian traffic only. No slip rating has been established
- Not under screeds or tiles, and not for negative-side hydrostatic pressure
Its FORSPEC systems
How to apply ACTFLEX 901 BUV
- 01
Prepare
Concrete cured 28 days, render and screed 7 days. Clean and dry, no standing water. Falls at least 1:100. On old membranes, cut out blisters and remove loose material.
- 02
Prime
No primer on sound, clean, dry substrate at 4% moisture or below. Above 4%, two coats of ACTFLEX EP250 and 24 hours cure. Never thin 901 BUV as a primer.
- 03
Detail
At junctions, penetrations and outlets, coat 100 mm onto each plane, embed the FORSPEC bandage in the wet coat, then coat over it. Carry the field coat 50 mm past the bandage.
- 04
Mix
Ready to use. Stir with a flat paddle at low speed. Do not dilute and do not mix at high speed. Reseal the pail straight away if not all is used.
- 05
Apply
Brush or roller, two coats to 1.5 mm total DFT, the second at right angles. Recoat after 8 hours, within 48. Do not try to build full thickness in one pass.
- 06
Cure
Protect from rain until the film is rain resistant. Light pedestrian traffic and full cure come at 7 days, then inspect.
A short guide from the data sheet. Read the full ACTFLEX 901 BUV 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.
ACTFLEX 901 BUV questions
Is ACTFLEX 901 BUV certified to an Australian Standard?
Not yet. No accredited third-party report to an Australian Standard is held, and verification testing to AS 4654.1 has been programmed. Check with FORSPEC Technical Services if certification is a condition of approval.
How much ACTFLEX 901 BUV do I need?
Two coats to 1.5 mm use 2.4 to 3.0 kg/m². An 18 kg pail covers 6.0 to 7.5 m² in theory and 5.1 to 6.8 m² in practice.
Can I walk on it?
Yes, pedestrians only, from 7 days after the final coat. It is not for vehicles, wheeled loads, point loads or machinery. No slip rating has been established.
Can I use it with polyurethane products?
No. Never overcoat it with, apply it over, or detail it with solvent-based or moisture-cured polyurethane, including ACTFLEX 929 SL, 929 HV, 75FC and MS PRO. Use FORSPEC bandage systems at corners.
Can it be used with FORZAFLEX sheet?
Yes. It is the approved termination and detailing membrane for the FORZAFLEX range: laps, upstands, penetrations, outlets and sheet edges. Clean talc and dust off the sheet first.
Used with ACTFLEX 901 BUV
ACTFLEX 901 BUV 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 ACTFLEX 901 BUV.