S11 Waterproofing

Note: The term contractor is used interchangeably to describe both subcontractors & suppliers


1.0 Scope

  • 1.1 Supply and install a complete system of waterproof membranes to decks, planters, below around structures and substrates where indicated on the architectural and structural drawings which are:
    • 1.11 Waterproof under five minutes duration rainfall of an intensity which has an average recurrence interval of 100 years.
    • 1.1.2 Graded falls to dispose of stormwater without ponding above the depth of lapped seams.
    • 1.1.3 Able to accommodate anticipated building movements.
    • 1.1.4 Able to accommodate its own shrinkage over the warranty life of the structure.

1.2 Related Work

  • 1.2.1 Close coordination is required with other sections as follows:
    • Concrete
    • Masonry
    • Roof and roof Plumbing Hydraulic services

1.3 Quality Assurance

  • 1.3.1 Suppliers and installers shall be widely experienced in the class of work required by this specification. Use only experienced sub-contractors licensed by the material supplier. Install under the direct supervision of a capable foreman with a proven background in inis trade.
  • 1.3.2 Use only Wrimco or Wolfin waterproofing system.

1.4 Reference Standards

  • 1.4.1 Comply with current relevant Australian Standards for materials and workmanship. Comply with the requirements of any building regulations applicable to the project.

1.5 Building Code of Australia

  • 1.5.1 Class of Building is Class 1a and 1b.
  • 1.5.2 Construction shall be carried out in accordance with the nDeemed-to-Satisfy Provisions” of the Building Code of Australia.

1.6 Delivery and Handling

  • 1.6.1 Keep on-site storage of materials to a minimum, delivering them as required for direct installation. Deliver, handle and store products in accordance with manufacturer’s recommendations and prevent damage deterioration or loss.

1.7 Warranty

  • 1.7.1 Waterproofing: Cover materials and workmanship in the terms of the warranty in the form of interlocking warranties from the supplier and the applicator.
  • 1.7.2 Form: Against failure of materials and execution under normal environment and use conditions.
  • 1.7.3 Period: As offered by the supplier, minimum 7 years.

1.8 Definitions

  • 1.8.1 General: For the purposes of this work-section the definitions given below apply:
  • 1.8.2 Substrates: The surface on which membrane systems are laid.
  • 1.8.3 Bitumen: A viscous material from the distillation of crude oil comprising complex hydrocarbons, which is soluble in carbon disulphide, softens when it is heated, is waterproof and has good powers of adhesion. It is produced as a refined byproduct of oil.
  • 1.8.4 SBS bitumen: Bitumen modified with Styrene Butadiene Styrene, a thermoplastic rubber that undergoes a phase inversion at elevated temperature and converts to an elastomeric material. The membrane is reinforced with fibreglass or non-woven polyester (NWP).
  • 1.8.5 APP bitumen: Bitumen modified with Atactic (meaning non-crystalline or amorphous) polypropylene wax to form a plastomeric sheet. The membrane is reinforced with fibreglass or non-woven polyester (NWP).
  • 1.8.6 Bona breakers: A system preventing a membrane bonding to the substrates.
  • 1.8.7 Membranes: Impervious barriers to liquid water which may be:
    • Liquid applied: Membranes applied in liquid or gel form and air cured to form a seamless film.
    • Sheet applied: Membranes applied in sheet form with joints lapped and bonded.
  • 1.8.8 Membrane systems: Combinations of membranes, flashings, drainage and accessories which form waterproof barriers and which may be:
    • Loose-laid.
    • Bonded to substrates fully or partially.
    • Fixed mechanically to substrates.
    • Protected either by ballast or an external insulation, also known as inverted membrane roof assembly (IRMA), or by both.
    • Trafficable, which may be for maintenance, pedestrians or vehicles.
  • 1.8.9 Plasticised PVC: Rigid PVC made flexible with plasticisers to form a plastic sheet membrane (vinyl).
  • 1.8.10 Seamless membranes: Membranes applied in liquid or gel form and air cured to form a seamless film.
  • 1.8.11 Slip sheets: Are used to isolate the membrane system from the supporting substrate or from the topping or mortar bedding above, are sometimes referred to as cleavage membranes, and are similar to bond breakers. The most common material is polyethylene sheeting.


2.1 Materials

  • 2.1.1 Contractor to select appropriate system from either Wolfin or Wrimco waterproofing membranes for the condition and construction sequence. Specification to be approved by Structural Engineer prior to placement.

2.2 Membranes

  • 2.2.1 To be proprietary membrane systems having one of the following certifying that the system is suitable for the intended external waterproofing, as follows:
  • 2.2.2 A current Australian Building Product and Systems Certification Scheme certificate issued by ABCB (Australian Building Codes Board).
  • 2.2.3 A current appraisal report issued by either CSIRO Building Products and Systems Appraisals.
  • 2.2.4 A current BRANZ Appraisal Certificate.

2.3 Accessories

  • 2.3.1 External outlets for membraned deck/balcony/planter
    • General: Proprietary funnel shaped sump cast into the roof slab, set flush with membrane, with removable grating and provision (e.g. clamp ring) for sealing the membrane into the base of the outlet. Refer Exterior Finishes Schedule and Hydraulic Engineer’s documents.
  • 2.3.2 External sub-soil drainage Walls
    • Material: AG line in filter sock, membrane to external wall (earth) face.
    • Filter: Geofabric
  • 2.3.3 Internal Floor Wastes: Turn membrane down onto the floor waste puddle flanges and adhere.
  • 2.3.4 Internal Hobs
    • General: Extend membrane over the hob and into the room at least 50mm.
    • For hobl-ess showers extend 1800mm into the room.
  • 2.3.5 Internal Wet Areas
    • Walls and floors of showers, baths, splashbacks and floor wastes: To BCA requirements.

2.4 Inspection Notice

  • 2.4.1 Inspection: unless agree otherwise, give notice so that inspection may be made as follows:
    • Substrate preparation completed.
    • Secondary layers preparation completed.
    • Before membranes are covered up or concealed.
    • Under-flashings complete prior to installation of over-flashings.
    • After flood testing.

2.5 Submissions

  • 2.5.1 Prior to ordering of materials submit samples and product data, msds & hazardous substances details  of all products intended for use.
  • 2.5.2 Execution records
    • Placing records: Photographically record the application of membranes and information as follows:
      • Portion of work.
      • Substrate preparation.
      • Weather during application and curing.
      • Protection provided from traffic and weather.


3.1 Examination

  • 3.1.1 Inspect conditions before delivery of materials and start of work on site to ensure that everything is satisfactory. Arrange with Principal for any needed rectification. Start of any work means total acceptance of all conditions.

3.2 Preparation General

  • 3.2.1 Prepare substrates as follows:
    • Fill all cracks in substrates wider than 1.5 mm with a filler compatible with the membrane system.
    • Fill voids and hollows in concrete substrates with a concrete mix not stronger than the substrate.
    • Remove projections.
    • Remove all traces of a concrete curing compound if used.
    • Remove deleterious and loose material.
    • Leave the surface free of contaminates, clean and dust free.

3.3 Moisture content

  • 3.3.1 Concrete substrates: Cure for >21 days.
  • 3.3.2 Moisture content: Verify that the moisture content of the substrate is compatible with the water vapour transmission rate of the membrane system by testing to current relevant Australian Standard.
  • 3.3.3 Test type: select from the following:
    • Hygrometer test: Seal a hygrometer to the substrate for >16 hours and measure the relative humidity of the air between the instrument and the slab.
    • Electrical resistance test: Connect a resistance meter to the slab and read the moisture content.

3.4 Falls

  • 3.4.1 Verify that falls in substrates are > 1.5%.

3.5 Joints and fillets

  • 3.5.1 Internal corners: Provide 45° fillets 50 x 50 mm (external works)
    • Material:
      • External corners: Round or arris edges (external works).
      • Movement control joints: Prepare all substrate joints to suit the membrane system.

3.6 Priming

  • 3.6.1 If required, prime the substrates with compatible primers to ensure adhesion of membrane systems.

3.7 Protection

  • 3.7.1 General: Protect membrane from damage during installation and for the period after installation until the membrane achieves its service characteristics that resist damage.

3.8 Drains

  • 3.8.1 General: Prevent moisture from tracking under the membranes at drainage locations.
  • 3.8.2 Drains and cages: Provide grates or cages, to prevent blockage from debris. If the finished surface is above the level or the membrane provide a slotted extension piece to bring the grate up to the level of the finished surface.
  • 3.8.3 Overflows: Turn the membranes into the overflow to prevent moisture from tracking behind the membrane.

3.9 Sheet joints

  • 3.9.1 Bituminous sheet membranes:
    • Side laps: 75 mm.
    • End laps: 100 mm.
  • 3.9.2 Method: Heat welded.
    • Synthetic rubber membranes:
    • Factory-vulcanized laps > 40 mm.
    • Field side laps > 50 mm for side laps.
    • Field end-laps > 100 mm for end laps.
  • 3.9.3 PVC (Polyvinyl chloride) membranes:
    • Factory welded laps > 30 mm.
    • Field-welded laps:
    • If used over insulation boards >100 mm.
    • Other instances > 75 mm overlaps.

3.10 Curing of liquid applied systems

  • 3.10.1 General: To the manufacturer’s’ instructions.

3.11 Movement control joints

  • 3.11.1 General: Locate over movement control joints in the substructure.
  • 3.11.2 Fillets and bond breakers: Provide of sufficient dimension to allow the membrane to accommodate the movement.
  • 3.11.3 Bonded membranes: Carry movement joints in the substrate through to and into the surface finish.

3.12 Membrane terminations

  • 3.12.1 Edge protection: Provide upturns above the maximum water level expected from the exposure conditions of rainfall intensity and wind.
    • Height: > 150 mm.
    • Anchoring: Secure sheet membranes along the top edge.
    • Edge protection: Protect edges of the membrane.
    • Waterproofing above terminations: Waterproof the structure above the termination to prevent moisture entry behind the membrane using cavity flashings, capping, waterproof membranes or waterproof coatings.
    • Horizontal terminations: Do not provide.

3.13 Membrane vertical penetrations

  • 3.13.1 Pipes, ducts, and vents: Provide separate sleeves for all pipes, ducts, and vents and have them fixed to the substrate.

3.14 Membrane horizontal penetrations

  • 3.14.1 Sleeves: Protect rigid PVC conduits and pipes with a sleeve of bitumen in order to seal to the membrane without burning the PVC. Do not use high density polyethlylene (HDPE), polypropylene (PP) pipes or flexible PVC conduit.

3.15 Balcony membrane about doors and windows

  • 3.15.1 Install membrane prior to the fixing of door or window frames.
    • Membrane upturn:
      • Sheltered areas: 40 mm above the finished external floor surface or overflow level, whichever is the higher.
      • Exposed areas: 150 mm upturn from the finished external floor level or overflow level, whichever is the higher.

3.16 Membrane around skylights and hatches

  • 3.16.1 Install membranes to upstands prior to the installation of the skylight or hatch.

3.17 Overlaying finishes on membranes

  • 3.17.1 Compatibility: If a membrane is to be overlayed with another system such as tiles, pavers, ballast, insulation or soil, provide an overlaying system that is compatible with and not cause damage to the membrane.
  • 3.17.2 Bonded or partially bonded systems: If the topping or bedding mortar requires to be bonded to the membrane, provide sufficient movement joints in the topping or bedding mortar to reduce the movement over the membrane.
  • 3.17.3 Double slip sheet: If the topping or bedding mortar is structurally sufficient not to require bonding to the substrate, lay a double slip sheet over the membrane to separate it from the topping or bedding mortar.
  • 3.17.4 Paint coatings: If maintenance pathways are indicated by a paving paint, ensure compatibility with the membrane.

3.18 Permanent membrane protection

  • 3.18.1 Protection board: 6mm FC sheet Location: Planter Boxes

4.0 Flood Test

  • 4.1 General
    • 4.1.1 Application: Perform a flood test prior to the installation of surface finishes.
    • 4.1.2 Set-up: Measure for dryness the wafl/floor junction of adjacent spaces to the slab soffit below using the electrical resistance test.
      • Record the result for each area.
      • Dam the access openings and seal drainage outlets to allow 50 mm water level but no higher than 25 mm below the weir level or the perimeter flashings.
      • Provide temporary overflows of the same capacity as the roof outlets to maintain the flood level.
      • Fill space with clean water and leave overnight.
  • 4.2 Evaluation: Make a visual inspection of the wall/floor junction of adjacent spaces and of the slab soffit below for obvious water or moisture.
  • 4.3Test the same areas for dryness using the moisture meter, and compare the results to the measurements taken prior to flooding.

5.0 Compliance:

5.1 Evidence of water from the visual test: Failure.

5.2 No visual evidence of water: Proceed with the moisture meter test.

5.3 increase in test results before and after flooding: Failure.

5.4 Records: Submit records of all flood tests.

6.0 Completion

  • 6.1 Protection
    • 6.1.1 General: Keep traffic off membrane surfaces until bonding has set or for 24 hours after laying, whichever period is the longer.
    • 6.1.2 Reinstatement: Repair or replace faulty or damaged work. If the work cannot be repaired satisfactorily, replace the whole area.

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