Showers are waterproof
The shower floor, every junction and every penetration is waterproof. Shower walls are waterproof to at least 1800 mm.
NCC HP 10.2.2 · Spec 26 S26C3● System 04 of 12 · Internal wet areas
Bathroom Waterproofing & Wet Areas
Bathrooms, showers and laundries to AS 3740. Primer, tape and collars, a Class III membrane, then tile straight onto it with BIOSET. Tested together to AS ISO 13007.5, under one FORSPEC warranty.
AS 3740AS/NZS 4858AS ISO 13007
7products
13CAD details
Up to 25 yrwarranty, depending on the systemwarranty, by system
● The build-up
Shower waterproofing: seven layers, in order.
Each layer with the one figure that matters, from its data sheet. Tap a layer to see why it is there.
01
PrimerACTFLEX EP 2500.32 kg/m² per coat · 24 h before the membrane
One coat on prepared concrete and masonry seals the surface so the membrane bonds. A 4 kg kit primes about 12.5 m² in one coat. Mix Part A and Part B 1:1 by volume and apply between 10 and 26°C.
02
Sealant at wastes and pipesACTFLEX MS PROTack-free in 15 minutes
Seals around the floor waste and pipe penetrations before the membrane goes on, and fills cracks over 2 mm once they are ground out to a 6 x 6 mm reglet. It also seals the tile movement joints at the end. 600 mL sausage, curing about 2 mm a day.
03
Tape at every junctionACTFLEX FLEX TAPE50 mm minimum overlap
Felt-backed tape bedded into the wet first coat at wall-to-floor and wall-to-wall junctions, so the membrane can move at the corner without tearing. Widths 120/70 and 150/100 mm, in 25 m rolls. Never bed it dry.
04
Collar at every tap and pipeSUPERFLEX COLLARFits 10 to 40 mm pipes
One pre-formed collar for each penetration. Coat at least 150 mm around the pipe, press the collar into the wet membrane, then coat over it.
05
MembraneACTFLEX 989 CWP1.2 mm in 2 coats · 18 kg ≈ 8 m²
Two-part cementitious membrane, Class III to AS/NZS 4858 (XTecGen Report 374-7). Two coats at about 0.92 mm wet each, in opposing directions. Recoat in 4 to 6 hours. Tile from 6 to 8 hours if the builder is not flood testing. Cover it within 5 days.
06
Membrane, the polyurethane optionACTFLEX 906 WPU1.2 mm in 2 coats · tile from 24 h
Single-pack water-based polyurethane, Class III to AS/NZS 4858 (XTecGen Report 251-5), with 517% elongation. Use it in place of 989 where a ready-mixed membrane suits the job. A 20 kg pail covers about 8 to 10 m². Not for particleboard or timber floors.
07
Tile adhesiveACTFLEX BIOSETC2TE S1 · grout from 24 h
Fixes tiles straight to the cured membrane with no primer or slip layer. Classified C2TE S1 to AS ISO 13007, and tested together with 989 CWP to AS ISO 13007.5 (Report 568-2). Full coverage and back-buttering in wet areas. A 20 kg bag covers about 4 to 4.5 m² with a 10 mm notch.
How much do I need?One 18 kg kit of ACTFLEX 989 CWP covers about 8 m² at 1.2 mm over two coats. Allow about 10% for tape, collars and laps.
Calculate →● The rules, in plain English
AS 3740 and the NCC, in short.
On a real job AS 3740 works together with the NCC's own wet area rules. The short version:
Timber floors: the whole floor
On a timber, particleboard or plywood floor, the whole bathroom floor is waterproofed, not just the shower.
NCC HP 10.2.3 · Spec 26 S26C4Falls of 1:80 to 1:50
A floor with a floor waste falls to it at between 1:80 and 1:50. That is 12.5 to 20 mm per metre.
NCC HP 10.2.12 · Vol One F2D4Open showers need a waterstop
No screen: a waterstop flush with the floor, at least 1500 mm from the rose. Hobless with a screen: a waterstop 5 mm high.
AS 3740 cl 4.8.2, 4.8.4Bond breaker at every corner
A bonded membrane needs one at every change of plane. Class III membranes, such as 989 CWP and 906 WPU, need the narrowest: 12 mm.
AS 3740 Table 4.10 · AS/NZS 4858Cure first, then test
Tile once the membrane reaches its maker's overlay time. A flood test is optional and the builder's call: wait for full cure, then hold the water 24 hours.
AS 3740 cl 4.5.2, 4.5.4, App CPDF989 CWP · AS/NZS 4858 Class III · Report 374-7989 · Class IIIPDFBIOSET · AS ISO 13007.2 · Report 571-2BIOSET · 13007.2PDF989 CWP + BIOSET · AS ISO 13007.5 · Report 568-2989 + BIOSET · 13007.5
A plain-English summary, not the standard. Check the current AS 3740 and NCC for your job, or send us the job and we will mark up the details.A summary, not the standard. Check the current documents for your job.
● Every product in this system
Internal wet areas: 7 products.
TDS and SDS open straight from the card.
● How it's done
Watch a shower waterproofed, start to finish.
ACTFLEX 989 CWP: how to waterproof a shower
- Check the substrate
- Puddle flanges + waterstop angles
- Prime + seal the penetrations
- Mix the kit
- Coat one, bandage + tap collars
● 3D models
See every layer before site starts.
Each FORSPEC detail is modelled in 3D so the site team sees the build-up for internal wet area waterproofing before anyone opens a pail. Send the job and we model yours.
● On site
Real jobs. Real FORSPEC.
Your job next
Got a job like this coming up?
Send the drawings or a few photos. A FORSPEC rep comes back with the system, the CAD details and a 3D of your job.
Send us your job →● CAD library
Drawn details, ready for your set.
13 standard details for internal wet area waterproofing. Open one to view it and download the PDF and DXF.
B100Bathroom Concrete UnderscreedStandard detail · PDF and DXF
B102Bathroom Concrete Over and UnderscreedStandard detail · PDF and DXF
B104Bathroom FC UnderscreedStandard detail · PDF and DXF
B106bShower Niche BandageStandard detail · PDF and DXF
B108FC Internal CornerStandard detail · PDF and DXF
B111Bath TubStandard detail · PDF and DXF
B112Laundry Powder RoomStandard detail · PDF and DXF
B113Shower BaseStandard detail · PDF and DXF● Questions we get
Straight answers, from the TDS.
How do you waterproof a bathroom and shower?
Prime the concrete with one coat of ACTFLEX EP250 and leave it 24 hours. Seal around the waste and pipes, bed tape into every junction and fit a collar on every tap. Then apply two coats of ACTFLEX 989 CWP to 1.2 mm dry and tile onto it with ACTFLEX BIOSET.
How long before I can tile over the waterproofing?
With ACTFLEX 989 CWP you can tile from 6 to 8 hours after the final coat at 25°C. That is if the builder is not flood testing. A flood test takes longer and is the builder's call under their inspection and test plan (ITP). With ACTFLEX 906 WPU, tile from 24 hours.
How much membrane do I need for a bathroom?
One 18 kg kit of ACTFLEX 989 CWP covers about 8 m² at 1.2 mm over two coats. Measure the floor plus the walls you are coating, then add about 10% for tape, collars and laps.
Do I need a primer under the membrane?
On concrete and masonry, yes: one coat of ACTFLEX EP250, left for 24 hours before the membrane. Abraded PVC panels need no primer under 989.
Can I tile straight onto the membrane?
Yes. ACTFLEX BIOSET goes directly onto cured ACTFLEX 989 CWP or 906 WPU with no primer or slip layer. Any other adhesive needs to comply with AS ISO 13007 and have written FORSPEC confirmation.
When can I flood test a shower?
Whether to flood test is the builder's call under their inspection and test plan (ITP). If they do, ACTFLEX 989 CWP can be tested from 48 hours after the final coat and ACTFLEX 906 WPU from 72 hours. Hold the water for 24 hours.
Which membrane class do I need for a shower?
AS/NZS 4858 sorts membranes by how far they stretch: Class I, II or III. ACTFLEX 989 CWP and 906 WPU are both Class III, the most flexible class, so the bond breaker at each junction can be the narrowest the standard allows.
Can the membrane go on a damp slab?
ACTFLEX 989 CWP goes on a cured slab that is damp but surface-dry, with no standing water and no active leaks. Where the slab reads over 4.5% moisture, apply two coats of ACTFLEX EP250 as the moisture-control primer first.
Is the system tested together to AS ISO 13007.5?
Yes. ACTFLEX 989 CWP and ACTFLEX BIOSET are tested together to AS ISO 13007.5 (XTecGen Report 568-2): 0.82 N/mm² initial adhesion against the 0.5 required, 0.89 mm crack bridging against 0.75, and no water penetration at 1.5 bar.
● Go deeper
Drawings, data sheets, jobs and news.
DrawingsCAD details for this system13 details here, PDF and DXF to download→Data sheetsTDS, SDS and test reportsEvery document for this system→CalculatorACTFLEX 989 CWP calculatorArea in, packs out→CalculatorACTFLEX 906 WPU calculatorArea in, packs out→SpecifySpec clause for this systemClause, drawings, data sheets→Projects12 buildings with these productsWhere this system has been used→NewsAS 3740: seven shower rules that get missedFORSPEC News→NewsFlood testing: what the standards sayFORSPEC News→NewsPuddle flanges: what AS 3740 requiresFORSPEC News→
● The other systems
Twelve systems. One warranty.
● Not sure it suits the job?
Send us the job. We spec it.
Drawings, photos or a description. A FORSPEC rep comes back with the system, the spec clause, CAD details and a 3D visual within 6 business hours.