ACTFLEX 988 CWP Cementitious membrane
Two-part flexible cementitious acrylic waterproofing membrane, below-ground and water-retaining
Class II membrane for basements, lift pits, tanks and pools. Positive or negative side.
How ACTFLEX 988 CWP goes on
ACTFLEX 988 CWP coverage, coats and cure times
Two-part cementitious acrylic membrane for basements, retaining walls, lift pits, water tanks and pools. Normally needs no primer on sound concrete and applies to cured, damp surfaces.
- Coverage
- ≈ 8–10 m²per 20 kg kit, 1.2 mm in 2 coats · TDS p4
- Below ground
- 1.5 mm3 coats with AT-MESH, about 6.4 to 8 m² per kit · TDS p4
- Recoat
- 4–6 h24 h minimum in confined underground areas · TDS p3
- Water pressure
- 350 kPatypicalhydrostatic pressure resistance (3.5 bar) · TDS p3
- Fill after
- 10 daysminimum cure before permanent immersion · TDS p3
- Tile from
- 48 hafter full cure, with BIOSET · TDS p3
- Class
- Class IIAS/NZS 4858 and AS 4654.1 · TDS p2
- Pack
- 20 kg kitPart A 8 kg liquid + Part B 12 kg powder · TDS p4
- Apply at
- 10–35°Cair and surface · TDS p3
From the FORSPEC data sheet, TDS-988CWP · 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.
ACTFLEX 988 CWP on site
More FORSPEC jobs
Where ACTFLEX 988 CWP is used
Use it for
- Basements, retaining walls and lift pits
- Water tanks, swimming pools and reservoirs
- Positive-side and negative-side systems
- PVC panel systems
- Internal and external wet areas
- Façades and efflorescence control
Know before you start
- Not a stand-alone UV-exposed membrane or a permanent trafficable surface
- Stop active water with ACTFLEX HYDROPLUG before waterproofing
- Negative-side PVC panel systems need FORSPEC approval before starting
- Apply the next layer within 5 days
How to apply ACTFLEX 988 CWP
- 01
Prepare
Sound, clean surface. New concrete cured 28 days, render 7 days. It may be damp but with no standing water or active leak.
- 02
Prime
Normally none: it is self-priming on sound, prepared concrete. ACTFLEX EP 250 on burnished, very rough or dense concrete. Prepared PVC needs no primer.
- 03
Detail
Option 1: ACTFLEX SA TAPE over junctions, joints and penetrations, lapped 50 mm. Option 2: a 35 x 35 mm ACTFLEX FLEXIPLUG cove with ACTFLEX AT-MESH bedded in the wet first coat.
- 04
Mix
Part A liquid to Part B powder 1 : 1.5 by weight, by machine only. Stand 3 to 4 minutes, then re-mix for 1 minute. Pot life is about 2 hours.
- 05
Apply
Two coats to 1.2 mm for wet areas. Three coats to 1.5 mm with AT-MESH below ground and in tanks and pools. Coats in alternating directions, recoat after 4 to 6 hours.
- 06
Cure
Full cure is 48 hours minimum, 7 days in confined areas and 10 days before a tank or pool is filled. Apply the next layer within 5 days.
A short guide from the data sheet. Read the full ACTFLEX 988 CWP TDS before you start.
How much ACTFLEX 988 CWP do I need?
Cementitious membrane, 20 kg kit
One 20 kg kit covers about 8 to 10 m² at 1.2 mm in 2 coats, or 6.4 to 8 m² at 1.5 mm in 3 coats. The calculator uses the low end, so you do not run short.
You need
0 kits
Where the figures come from
One 20 kg kit covers about 8 to 10 m² at 1.2 mm in 2 coats, or 6.4 to 8 m² at 1.5 mm in 3 coats. The calculator uses the low end, so you do not run short.
- 20 kg kit at 1.2 mm, 2 coats: about 8 to 10 m² (8 used). TDS-988CWP, R2, 12 Aug 2026, page 4
- 20 kg kit at 1.5 mm, 3 coats: about 6.4 to 8 m² (6.4 used). TDS-988CWP, R2, 12 Aug 2026, page 4
More: ACTFLEX 988 CWP product page · Below ground system · Negative side system · Pools & tanks system
Where it has been used
FORSPEC projects built with ACTFLEX 988 CWP.
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 988 CWP test reports and compliance
- AS/NZS 4858:2004
- Complies, Class II; cyclic movement passXTecGen Report 250-2
- AS 4654.1-2012
- Complies, Class II, fully bonded non-exposed; cyclic movement passXTecGen Report 250-3
- Adhesion to prepared PVC
- 1.44 MPa mean pull-off, PVC substrate failureASTM D4541-02
- VOC content
- 2 g/LFORAY Certificate P23010038
Download the reports
Results as stated in the data sheet, TDS-988CWP · Revision 2 · 12 August 2026. Warranty up to 25 years, depending on the system: ask FORSPEC which term applies to your system.
ACTFLEX 988 CWP questions
Can ACTFLEX 988 CWP be used on the negative side?
Yes. It is approved for positive-side and negative-side systems. Stop any active water with ACTFLEX HYDROPLUG first, detail with ACTFLEX FLEXIPLUG, then apply three coats to 1.5 mm with ACTFLEX AT-MESH in the first coat.
How much ACTFLEX 988 CWP do I need?
A 20 kg kit covers about 8 to 10 m² at 1.2 mm in two coats, or about 6.4 to 8 m² at 1.5 mm in three coats. Allow extra for wastage, surface profile and detailing.
Do I need a primer?
Normally no. It is self-priming on sound, correctly prepared concrete. Use ACTFLEX EP 250 on burnished, very rough or dense concrete. Prepared PVC panels need no primer.
How long before a tank or pool can be filled?
At least 10 days after the final coat, with ventilation in tanks and confined structures.
Can I tile over it?
Yes, after full cure, which is a minimum of 48 hours, using ACTFLEX BIOSET.
Can it be left exposed?
No. It is not a stand-alone UV-exposed membrane and not a permanent trafficable surface. Apply the next layer within 5 days.
Used with ACTFLEX 988 CWP
ACTFLEX 988 CWP TDS and SDS
Show all 8 documents ↓
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 988 CWP.