ACTFLEX 75FC PU sealant
Multi-purpose fast-cure polyurethane adhesive joint sealant
Fast-cure, non-sag polyurethane joint sealant and adhesive for movement joints, junctions and penetrations.
ACTFLEX 75FC coverage, coats and cure times
One-component moisture-curing polyurethane sealant in grey 600 mL sausages. It bonds to concrete, masonry, fibre cement, metal, timber and primed PVC.
- Skin time
- ≈ 65 mintypicaltool before the sealant skins · TDS p2
- Cure rate
- ≈ 3.5 mm/24 htypicalslower in cool or dry air and at depth · TDS p2
- Minimum joint
- 6 x 6 mmsealant depth 6–15 mm; over 12 mm wide at 2:1 · TDS p2
- Movement
- 12.5%typicalmovement accommodation factor · TDS p2
- Joint yield
- ≈ 6.0 mper 600 mL sausage at 10 mm x 10 mm · TDS p3
- Membrane over
- 24 h mintypicalonce skinned, firm and tack-free; longer for deep fills · TDS p4
- Immersion
- 5 daystypicalminimum cure before water-immersion service · TDS p2
- Apply at
- 10–26°Cambient and substrate · TDS p2
- Pack
- 600 mLsausage, grey · TDS p2
From the FORSPEC data sheet, TDS-75FC · Revision 2 · 12 August 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 75FC is used
Use it for
- Movement and control joints in concrete and masonry
- Sealed crack and junction details within FORSPEC membrane systems
- Joint sealing beneath and adjoining solvent-based waterproofing
- Penetrations in walls and floors: pipes, services and fixings
- Bonding metal angles to concrete, fibre cement, timber and primed PVC
- Exterior lap seams: truck trailers, metal roofs, window perimeters
Know before you start
- Not for structural glazing or continuous chlorinated-water immersion
- Not for damp, frosted or contaminated surfaces, or outside 10–26°C
- Joint movement must not exceed the 12.5% movement accommodation factor
- Over-paint only after full cure, after a compatibility trial
Its FORSPEC systems
How to apply ACTFLEX 75FC
- 01
Prepare
Joint faces sound, clean, completely dry and free of oil, grease, paint, laitance, efflorescence and curing compounds. Repair voids with non-shrink mortar.
- 02
Prime
ACTFLEX 700 PU PRIMER on dry internal surfaces. ACTFLEX SUPERBOND 007 on metal, wood and PVC. ACTFLEX EP250 on external or uneven cementitious surfaces. Dry fully; never pool primer.
- 03
Backing rod
Fit closed-cell rod about 25% larger than the joint width after priming, or bond-breaker tape. Minimum joint 6 x 6 mm. Never allow three-sided adhesion.
- 04
Gun
Load the 600 mL sausage into a barrel gun and trim the nozzle. Extrude continuously with the nozzle deep in the joint. Wider joints take several passes.
- 05
Tool
Tool straight away with a curved spatula, before it skins (about 65 minutes). A 20% household detergent solution on the tool stops pick-up. Keep it off the joint faces.
- 06
Cure
Cures about 3.5 mm per 24 hours. Apply membranes once skinned and tack-free, minimum 24 hours. Water immersion after 5 days. Over-paint after full cure.
A short guide from the data sheet. Read the full ACTFLEX 75FC TDS before you start.
ACTFLEX 75FC questions
How far does a 600 mL sausage go?
Width x depth in mm gives mL per metre. A 10 mm x 10 mm joint gives about 6.0 m, 10 mm x 6 mm about 10.0 m and 20 mm x 10 mm about 3.0 m. Allow about 10% for tooling and wastage.
Which primer do I use with ACTFLEX 75FC?
ACTFLEX 700 PU PRIMER on completely dry internal surfaces. ACTFLEX SUPERBOND 007 on metal, wood and PVC. ACTFLEX EP250 on external or uneven cementitious surfaces.
How long before I can put a membrane over it?
Once it is fully skinned and tack-free, a minimum of 24 hours, and longer for deep fills. Follow the relevant FORSPEC membrane TDS.
When can it be immersed in water?
Only after a minimum of 5 days cure. It is not for continuous chlorinated-water immersion such as pools.
What temperatures can I apply it in?
10 to 26°C, ambient and substrate, to completely dry, sound surfaces. Never apply to damp, frosted or contaminated surfaces.
Where does 75FC go in a FORSPEC system?
It is the specified sealant for sealed crack and junction details, as the relevant membrane TDS says. It also seals joints beneath and adjoining solvent-based waterproofing.
Used with ACTFLEX 75FC
ACTFLEX 75FC 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 75FC.