Platinum PM3 - Non-Meshed Damp Proof Membrane (3mm Stud)

Health & Safety And Installer Competency

Read the current PM3 information and the separate instructions and safety data for every fixing, tape, treatment, drainage, pump and lining product before work begins. Wear suitable gloves, eye protection and safety footwear, with dust extraction and respiratory protection during drilling or substrate preparation. Check for concealed electrical cables, gas pipes, water services and structural hazards before drilling.

The cause and severity of moisture must be diagnosed before PM3 is specified. Above-ground damp treatment requires knowledge of rising damp, rain penetration, leaks, condensation, salts and decay. Below-ground Type C work requires a waterproofing design covering groundwater risk, drainage capacity, discharge, pumping resilience, ventilation, access and maintenance.

Complex retaining structures, habitable basements, high water-risk sites, vaulted soffits, pumped systems, historic masonry, structural movement, severe contamination or warranty-controlled work should be designed and installed by suitably competent specialists.

Intended Use And System Selection

Use PM3 on suitable above-ground walls where the purpose is to isolate a mechanically supported or independent internal finish from dampness and salts. The wall must be non-earth-retaining unless PM3 is being installed as part of a separately designed Type C drained waterproofing system.

Below ground, PM3 may be installed across suitable retaining walls, floors, tunnels and correctly falling vaulted or sloping soffits. It must connect continuously to AquaTrack drainage and a dependable gravity outlet or AquaSump arrangement. The membrane does not resist hydrostatic pressure as a standalone sheet.

Confirm the finish before installation. PM3 is non-meshed and cannot receive direct plaster or render. Use treated battens and supported boards, an independent frame, a compatible wall-supported system, a properly restrained masonry lining or an approved protected floor build-up.

Suitable Substrates And Finishes

Surface Preparation

Remove loose debris, dust, organic matter, sharp projections and unstable materials. Existing plaster should normally be removed because it can soften and weaken the membrane fixing. Sound, well-bonded render may remain, but loose, hollow, crumbling or friable areas must be removed or repaired so the specified fixings reach a dependable substrate.

Identify and correct avoidable moisture sources. Where rising damp is correctly diagnosed and a chemical DPC is specified, install DampSolve Damp Proof DPC Cream in accordance with its instructions. Repair defective rainwater goods, external finishes, pointing, plumbing leaks and other building faults before the wall is concealed.

Where dry rot has affected suitable masonry, apply Lignum Pro M50 in accordance with its label and instructions as part of the remedial specification. Wet rot, timber decay, insect attack and other biological contamination require appropriate specialist assessment and treatment; covering affected material with PM3 is not acceptable.

Prepare below-ground drainage routes, local repairs, troughs, sumps and outlets before fixing the membrane. Treat suitable concrete with Wykamol Anti-Lime Sealer where free-lime deposits could obstruct the shallow cavity or AquaTrack system.

Tools And Ancillary Products Required

Typical tools include a good-quality SDS hammer drill, sharp 10mm masonry bits, a rubber mallet or suitable wide-headed hammer, utility knife with spare blades, scissors or shears, tape measure, pencil, long spirit level, hand roller and clean dry cloths. A rotating laser is helpful for setting out levels and drainage routes.

Above-ground work normally requires the fixing selected for the substrate, 150mm Platinum Corner Tape and any Waterseal Rope or Joint Sealing Membrane Tape needed for planned details. Below-ground work additionally requires sealed wall or soffit fixings, AquaTrack components, a dependable gravity or pumped outlet, inspection access and the specified protected finishes.

Cutting And Setting Out

Measure each surface and decide whether horizontal or vertical wall installation will produce the neatest layout with the fewest unnecessary joints. Coordinate sheet edges with corners, reveals, returns, services, AquaTrack, floor levels and the fixing centres required for battens, brackets or wall ties.

Cut PM3 with a sharp utility knife, scissors or shears. Support the membrane while cutting and avoid ragged edges, unnecessary holes or cuts extending beyond the intended termination. Keep standard sheet joints straight and accessible for face-applied Corner Tape.

For below-ground areas, mark the complete drainage route, channel fittings, inspection ports, outlet or sump position and wall-to-floor junction before membrane installation begins. Do not create isolated cavities that cannot discharge.

Above-Ground Wall Installation

Position PM3 with the studs facing the wall and the smooth surface towards the room. Align the first sheet accurately, then hold it without stretching or distorting the studs while the initial fixings are installed.

PM3 may be fitted horizontally or vertically. Drill through the centre of a selected stud into sound substrate using the bit and depth required for the chosen Platinum fixing. Install only enough initial plugs to hold the sheet neatly, then add fixings at the centres required by the battens, brackets or masonry ties.

Continue PM3 into the ceiling void and below the finished floor line where practicable, or finish it tightly at the soffit and floor. Do not leave deliberate gaps to ventilate the membrane cavity. Bring adjoining sheets together as close butt joints ready for 150mm Platinum Corner Tape.

Below-Ground Type C Design And AquaTrack Drainage

Every below-ground PM3 cavity must connect to a continuous water-management route. Wall membrane, floor membrane, AquaTrack, Floor Drain Channel, outlets, AquaSump chambers and discharge pipework should operate as one coordinated arrangement without backfalls, trapped sections, blocked entries or sealed pockets.

The waterproofing designer must assess retaining conditions, groundwater risk, structure, cracks, movement joints, wall and slab junctions, anticipated inflow, drainage capacity, pump duty, head, discharge route, alarm provision, power-loss resilience, ventilation and maintenance access.

Where gravity drainage is unavailable, select an AquaSump system with capacity and resilience appropriate to the design flow and assessed consequences of failure. Provide duty and standby pumps, high-water alarms, battery back-up or telemetry where the risk assessment requires them. Keep all access points and covers permanently reachable.

Platinum AquaTrack Channel positioned at the wall-to-floor junction to collect water from behind Platinum PM3 Damp Proof Membrane, with Platinum Corner Tape securing the channel to the Newton Condensation Strip and Newton CDM Fibran XPS 500-C Insulation beneath (via Platinum PM3 Damp Proof Membrane as a floor membrane).

Platinum AquaTrack Preparation And Installation

Form the AquaTrack route to the project drawings without weakening the structure. Provide a stable trough and bed, align the channel correctly at the wall-to-floor junction and use purpose-made connectors, swept corners, T-pieces, end caps, floor-drain sections and compatible outlets rather than improvised cuts.

Install an AquaTrack Inspection Port at every applicable change of direction using a compatible push-out position. Add In-Line Access Ports on longer straight runs wherever required by the maintenance design. Keep every cap visible, reachable and removable after skirtings, linings and flooring are fitted.

Before concealment, flush or water-test the channel route and confirm free flow to the gravity outlet or AquaSump. Rectify debris, leakage, poor connections, backfalls, standing water and inaccessible service points before proceeding.

Wall Installation With Sealed Fixings

For below-ground walls, position PM3 with the studs against the structure and the smooth face towards the room. Set sheets level and keep the membrane close to corners without stretching, sagging or crushing the stud profile.

Drill through the centre of the selected stud into sound masonry using a 10mm SDS bit. Insert a Platinum Waterseal Brick Plug squarely and drive it home until the fitted rubber washer lies flat and compresses evenly against PM3. Replace plugs with damaged, folded or poorly seated seals.

Where Brick Plugs Without Seals form part of a separately sealed detail, position a continuous ring of Platinum Waterseal Rope around the fixing and compress it firmly between the plug head and membrane. Do not use an unsealed fixing below ground or where water could reach the penetration.

Fixing To Weak Or Friable Above-Ground Substrates

Use Platinum Cob Plugs only where a compatible weak, friable or low-density above-ground substrate prevents a standard masonry plug from obtaining dependable grip. Follow the separate fixing instructions and seal each penetration where required by the damp-proofing detail.

Drill the correct hole without repeatedly enlarging it, remove loose dust and insert the fixing squarely. Drive the expansion pin fully so the plug anchors as intended without crushing the membrane studs or tearing the sheet.

Severely crumbling, detached or structurally unsound masonry must be repaired before installation. Cob Plugs do not convert an unsuitable retaining wall into an acceptable Type C fixing substrate and must not be substituted for a designed sealed below-ground fixing.

Membrane Jointing

PM3 sheet joints may run horizontally or vertically. Bring adjoining straight edges tightly together to form a clean close butt joint. Do not overlap the studded sheets, leave an open gap or force distorted edges into contact.

Clean and dry both membrane faces before applying 150mm Platinum Corner Tape. Centre the tape over the joint so approximately equal widths bond to each sheet, remove the release liner progressively and press or roll firmly across the complete face.

Work along the seal to remove wrinkles, bridging, trapped air and incomplete contact. In cold or damp conditions, use controlled warm air to remove surface moisture and improve tack without overheating the HDPE or butyl. Keep every completed joint visible for inspection before finishes are installed.

Corners, Returns And Reveals

Take PM3 around internal and external corners where a neat fold can be formed without stretching or distorting the stud profile. Work the sheet closely into the angle and maintain the correct orientation throughout the return.

If the wall contour causes the membrane to become misshapen, stop at a controlled position and begin again with a new membrane section. Form a close butt joint and seal it centrally with 150mm Platinum Corner Tape. Use Waterseal Rope and a compatible patch where a three-dimensional detail cannot maintain full tape contact.

Continue PM3 onto return walls where damp or water could otherwise pass around the treated area. Coordinate window and door reveals, frames, sills, thresholds and perimeter junctions with the final lining and, below ground, the continuous drainage arrangement.

Timber Battens, Dry-Lining Frames And Masonry Linings

Select preservative-treated timber battens suitable for the environment and coordinate every batten position before membrane fixing. Add Platinum Waterseal Brick Plugs at the centres required to carry the lining safely, rather than relying only on plugs used initially to hold PM3.

Fix suitable battens or lining brackets through the hollow plug cores using controlled-length 5mm (No. 10) screws. Each screw must engage securely without passing beyond the plug and puncturing PM3. Do not form separate uncontrolled screw holes through the membrane.

Independent timber or metal frames can minimise direct loading. Wall-supported metal systems and internal masonry linings require compatible brackets or ties, designed support, suitable head restraint and coordinated openings. Follow the lining manufacturer’s requirements for centres, board thickness, insulation, fire performance and maximum wall height.

Wall-To-Floor Junction And DPM Continuity

For above-ground work incorporating a new slab, install PM3 before concrete placement where practicable. Continue the wall membrane to the required lower level so the floor damp-proof membrane can extend upwards in front of it, maintaining the designed damp-proof continuity.

Coordinate the wall membrane, floor DPM, slab, insulation, screed and finished floor level before work begins. Protect PM3 during reinforcement placement, concrete pouring, compaction and follow-on trades, and repair every puncture before concealment.

This detail is for above-ground damp control. It must not be used as a substitute for AquaTrack drainage where the wall retains earth or groundwater can enter the structure.

Wall-To-Floor Junction And AquaTrack Integration

In a below-ground Type C system, the wall-to-floor junction must allow water from the wall and floor cavities to enter AquaTrack without passing into the protected floor build-up. Position PM3 and the AquaTrack upstand to the approved project detail.

Where PM3 continues across the floor, connect the wall and floor sheets or the channel upstand using the specified combination of 150mm Platinum Corner Tape and Waterseal Rope. Form corners without bunching the membrane, blocking channel openings or pulling tape across unsupported voids.

Before installing the floor finish, introduce controlled clean water behind the wall membrane and confirm that it reaches AquaTrack and flows freely to the outlet or AquaSump. Rectify slow flow, standing water, leakage, trapped sections and incomplete seals before concealment.

Floor Installation

Provide the designed AquaTrack drainage and discharge route before laying PM3 below ground. The concrete base must be clean, stable and free from oil, loose material and sharp projections. Where a board finish will be laid directly above PM3, the supporting concrete base must not deviate by more than 5mm beneath a 2m straightedge.

Loose-lay PM3 with the studs facing down. Cut neatly around channels, columns, sumps and unavoidable services without stretching the sheet. Never fix the floor membrane through to the slab.

Bring adjacent sheets together as close butt joints without overlap, then centre 150mm Platinum Corner Tape over each clean, dry joint. Compress the tape firmly and keep both sheet edges aligned.

Protect the membrane promptly. Use a compatible tongue-and-groove board build-up, Newton CDM Fibran XPS 500-C within a load-checked construction, at least 50mm reinforced concrete or screed directly over PM3, or at least 65mm reinforced concrete or screed over compatible insulation, subject to the complete project design.

Vaulted And Sloping Soffit Installation

PM3 may be installed to suitable arched, vaulted or sloping retaining soffits where the construction provides a dependable minimum 10% fall towards the designed drainage point. Survey the full geometry, end walls, joints, depressions and discharge route before cutting.

Position the studs towards the soffit and use separately sealed Platinum Brick Plugs Without Seals with a continuous compressed ring of Platinum Waterseal Rope. Provide enough fixings to prevent sagging, open folds or pockets that could retain water and debris.

Form section joints as close butt joints sealed centrally with 150mm Platinum Corner Tape. Turn the soffit membrane down each end wall by at least 200mm and fit the wall membrane in front so water continues towards drainage. Flat retaining soffits are unsuitable for PM3.

Pipes, Services And Other Protrusions

Plan pipes, cables, conduits, sockets and controls before PM3 is installed and keep them on the protected side wherever practical. Every penetration creates a potential route for dampness, salts or water to reach the internal construction.

Where a service must pass through PM3, cut the smallest neat opening and fill the remaining gap with compressed Platinum Waterseal Rope. Add a compatible membrane patch and seal it with Platinum Joint Sealing Membrane Tape or Corner Tape where required by the shape and movement of the detail.

Use a suitable collar or sleeve for larger, grouped, hot, moving or irregular services where a simple rope-and-patch detail cannot maintain continuity. Avoid general-purpose tape, expanding foam or unconfirmed sealants as the primary damp-proofing or waterproofing detail.

Protection And Internal Finishes

Protect PM3 as soon as fixing, jointing and inspection are complete. Suitable wall finishes include treated battens carrying plasterboard or wooden sheeting, independent timber or metal frames, compatible wall-supported systems and properly restrained internal masonry linings.

The membrane is classified as Class E and must be covered by a construction that provides the fire protection required for the building and room use. The finish must also protect PM3 from ultraviolet light, impact, abrasion and accidental puncture throughout service.

Do not plaster, render or bond dot-and-dab plasterboard directly to the smooth non-meshed face. Tell follow-on trades where the membrane, drainage and no-fix zones are located. Later fittings and services must use planned supports or an approved sealed penetration detail.

Ventilation And Humidity Control

PM3 has high resistance to vapour diffusion. When positioned on the cold side of insulation, it can increase interstitial-condensation risk unless the construction and internal environment are designed correctly. Carry out the appropriate BS 5250:2021 assessment and specify a warm-side vapour-control layer where required.

Rooms still need suitable ventilation, heating and humidity control for their intended use. Bathrooms, kitchens, utility rooms, occupied basements and other moisture-producing areas may require mechanical extract ventilation or a designed environmental-control strategy.

Do not open the membrane cavity directly to the room as an improvised condensation measure. Investigate condensation on the protected finish as an environmental or construction issue rather than assuming it indicates failure of PM3.

Inspection Before Finishes

Inspect the complete PM3 installation before battens, frames, boards, masonry, flooring, concrete or screed conceal it. Confirm the membrane orientation, alignment, fixing security and condition of every studded area.

Check each close butt joint, corner, reveal, service penetration, wall base, floor connection, soffit detail and local repair. Confirm 150mm Platinum Corner Tape remains centred and firmly compressed, and replace any contaminated, loose or damaged seal.

For below-ground work, vacuum cavity edges and channels, flush AquaTrack and verify free flow to the outlet or AquaSump. Test pumps, floats, alarms and any back-up arrangements. Repair all faults before approving concealment and retain photographs of critical details.

Repairs To Platinum PM3

Clean and dry the membrane around every damaged area before repair. Small punctures and clean cuts can be sealed with a suitable patch of Platinum Corner Tape extending onto sound PM3 beyond the complete defect.

For larger tears or irregular damage, use a compatible PM3 offcut extending well beyond the affected area. Preserve the studded cavity and seal the patch perimeter using Platinum Waterseal Rope, Joint Sealing Membrane Tape or Corner Tape as required by the approved detail.

Replace the affected section where crushed studs, contamination, extensive damage or a critical junction prevents a dependable local repair. Reinspect the finished work and repeat the relevant water test before the area is concealed.

Maintenance And Future Alterations

Protected PM3 requires no routine surface maintenance under normal service conditions. Above-ground linings must nevertheless remain intact, and any later penetration should use a planned fixing position or an appropriate sealed detail.

Below-ground Type C systems require continued maintenance. Keep AquaTrack, Floor Drain Channel, inspection ports, outlets, AquaSump covers, pumps, alarms, back-up equipment and discharge pipework accessible. Inspect, flush, clean and test them at the intervals set by the waterproofing designer and equipment manufacturers.

Provide the building owner with drawings, photographs, test records, no-fix zones, access-point locations, pump instructions and maintenance schedules. Contractors altering the space should review this information before drilling, lifting floors or opening linings.

Key Limitations

• PM3 is non-meshed and cannot receive direct plaster, render or dot-and-dab plasterboard. Use a compatible mechanically supported or independent wall finish.
  
  

• Above-ground use isolates protected finishes but does not correct the moisture source. Diagnose and address leaks, rising damp, condensation, external defects and decay as required.
  
  

• Below ground, PM3 is not a standalone hydrostatic barrier and must connect continuously to designed AquaTrack drainage and a dependable gravity or pumped discharge.
  
  

• Standard sheet joints are close butt joints sealed centrally with 150mm Platinum Corner Tape. Do not overlap PM3 sheets or leave joint edges open.
  
  

• Floor PM3 must remain loose-laid and must not be punctured by fixings. Protect the studs and verify every floor build-up for loading and compatibility.
  
  

• Flat retaining soffits are unsuitable. Arched, vaulted and sloping soffits require separately sealed fixings, no sagging and a dependable minimum 10% fall.
  
  

• Hazardous chemicals, unknown industrial residues, active structural movement and unstable substrates require specialist investigation and project-specific assessment before concealment.
  
  

• Class E applies to PM3 itself. The complete protected wall or floor construction must satisfy the applicable fire-safety and Building Regulations requirements.
  
  

• High vapour resistance can increase condensation risk on the cold side of insulation. Coordinate thermal design, ventilation, heating and any required vapour control.
  
  

• Keep exposed and installed PM3 protected from ultraviolet light, excessive heat, open flame, impact, abrasion and uncontrolled penetrations by follow-on trades.

Storage And Shelf Life

Store PM3 rolls upright in their protective wrapping, under cover and away from direct sunlight, excessive heat, ignition sources, sharp objects and contamination. Do not stack or position rolls where the 3mm profile may be crushed, distorted or punctured.

Keep Platinum tapes, Waterseal Rope and plug seals clean and dry within the storage conditions stated on their packaging. Protect AquaTrack components from impact and deformation, and store mortars, biocides, DPC cream and Anti-Lime Sealer according to their separate labels.

Inspect all products before use. Reject membrane with tears, brittle areas, badly crushed studs, permanent distortion or contamination that prevents a dependable seal. Published PM3 information relates to the membrane’s service life after correct installation and protection; it does not state a finite shelf life for an unused wrapped roll.

Other Technical Information

Platinum PM3 is supplied in 2m x 10m and 2m x 20m rolls with nominal areas of 20m² and 40m². Calculate actual requirements with allowance for cuts, corners, reveals, returns, openings, junctions, service details, repairs and reasonable site waste.

Published data records a unit weight of 500g/m², sheet thickness of 0.6mm, 3mm stud height, 20mm stud centres and air-gap volume of 2.19 litres/m². Water-vapour resistance is above 3020MNs/g, while the stated working range is -50°C to +80°C.

Tensile strength is 416N in the machine direction and 488N across the sheet. Resistance to static loading is above 20kg, compressive strength is 250kN/m² and the declared reaction-to-fire classification is Class E.

Technical values describe membrane performance rather than the completed wall, floor or waterproofing system. Drainage capacity, structural loading, insulation, screed reinforcement, fire protection, condensation control, penetrations, pumping resilience, maintenance and final occupancy require separate project-specific coordination.

Q) What is Platinum PM3 Non-Meshed Damp Proof Membrane?

A) Platinum PM3 is a low-profile, studded HDPE membrane designed primarily to isolate protected internal finishes from damp, salts and water-affected substrates. Its 3mm studs create a narrow cavity between the existing background and the new lining, while its non-meshed face suits mechanically supported finishes rather than direct plastering. Typical applications include damp above-ground walls, cellars, floors, tunnels and suitably sloping vaulted structures. PM3 can also form the membrane component of a professionally designed Type C drained waterproofing system below ground. It is not a decorative finish or a standalone cure for the moisture source, so the substrate, drainage requirements and intended wall or floor construction must be assessed before installation.

Q) How does Platinum PM3 Damp Proof Membrane work?

A) Platinum PM3 forms a physical separation layer between a damp or salt-contaminated background and the protected internal finish. The 3mm studs face the substrate, holding the main sheet away from the wall or floor and creating narrow channels for vapour equalisation or controlled water movement. Above ground, this separation helps stop dampness and salts transferring directly into boards, timber sheeting or other supported finishes. Below ground, water entering through the structure is directed within the cavity towards a continuous drainage system and dependable discharge point. PM3 does not stop hydrostatic pressure by itself or remove the underlying moisture source. Its success depends on correct joints, sealed fixings, compatible finishes and, where required, properly maintained drainage.

Q) What does non-meshed mean on Platinum PM3 Membrane?

A) Non-meshed means the room-facing surface does not include a bonded fabric or mesh intended to provide a key for wet plaster or render. Platinum PM3 is therefore designed for dry finishes supported independently or mechanically, such as treated timber battens with boards, timber or metal dry-lining frames, compatible wall-supported systems or a properly restrained internal block wall. This smooth construction is useful where direct plastering is unnecessary and a clean separation layer is preferred. Conventional plaster, render and dot-and-dab plasterboard must not be applied directly to PM3 because they cannot form a dependable bond. The selected lining should protect the membrane from damage, fire exposure and uncontrolled penetrations while meeting the room’s loading and finish requirements.

Q) Why does Platinum PM3 have a 3mm studded profile?

A) The compact 3mm profile creates separation and limited drainage space while using less internal depth than a larger-studded cavity membrane. This makes Platinum PM3 particularly helpful around stairs, narrow corridors, window reveals, thresholds, low ceilings and refurbishment areas where valuable room space or headroom must be preserved. The shallow profile also keeps compatible floor constructions relatively compact. However, the reduced cavity must remain exceptionally clean and unobstructed, especially below ground. Drilling dust, mortar, lime deposits, silt, crushed studs or poorly formed joints can restrict the available flow route. Water-risk assessment and drainage design are therefore essential when PM3 is used as part of a Type C system rather than solely as an above-ground damp-isolation membrane.

Q) Which roll sizes are available for Platinum PM3?

A) Platinum PM3 is available in 2m x 10m and 2m x 20m rolls, providing nominal coverage of 20m² and 40m² respectively. Nominal roll area should not be treated as the exact finished coverage for every project. Measure walls, floors, reveals, returns, columns, steps and other surfaces separately, then allow for cuts, corners, openings, service details, repairs and reasonable site waste. The membrane has no jointing flange, so the planned sheet layout should also account for close butt joints sealed with 150mm Platinum Corner Tape. A drawn layout is especially useful for irregular cellars or combined wall-and-floor work, as it helps position joints efficiently and identify the required tapes, fixings, drainage components and finishing materials before installation begins.

Q) What are the main advantages of Platinum PM3 Membrane?

A) Platinum PM3 provides a durable internal separation layer without relying on continuous adhesion to a damp or salt-affected substrate. Its shallow 3mm stud profile preserves space, the HDPE sheet cuts easily, and wall sheets may be installed horizontally or vertically to suit the layout. Sound existing render can sometimes remain, reducing disruptive preparation, while the non-meshed surface works well behind framed, battened or masonry linings. PM3 can serve both above-ground damp-proofing projects and suitable below-ground Type C designs, which gives it broad refurbishment potential. Installation has no membrane curing period. These advantages depend on correct product selection: direct plastering is unsuitable, below-ground water needs drainage, and every joint, fixing, penetration and finish must form part of a coordinated system.

Q) Where can Platinum PM3 be used above ground?

A) Above ground, Platinum PM3 is suited to internal walls where dampness, hygroscopic salts or staining could affect a new mechanically supported finish. Common applications include older brick or stone properties, utility rooms, storage areas, renovated ground-floor rooms, chimney breasts and walls treated for rising damp. It may be installed over sound concrete, brickwork, blockwork, compatible stone masonry or well-bonded render after unstable material and avoidable moisture sources have been addressed. The membrane isolates the finish but does not repair leaking plumbing, defective rainwater goods, bridging, condensation or structural faults. Return walls, reveals and junctions should be assessed because moisture can bypass an incomplete treatment. Heating, ventilation and insulation still require separate consideration for a comfortable internal environment.

Q) Can Platinum PM3 be used when treating rising damp?

A) Platinum PM3 can isolate a protected internal lining from residual dampness and salts where a competent investigation confirms rising damp. It is normally used alongside an appropriate remedial damp-proof course and any necessary repairs rather than as a substitute for controlling moisture entry. Remove salt-contaminated or weakened plaster where required, treat the diagnosed cause and continue the membrane across the intended treatment area, including vulnerable returns and reveals. The lower termination must coordinate with the floor damp-proofing detail so moisture cannot pass behind the new finish at the wall base. Because condensation, plumbing leaks and high external ground levels can resemble rising damp, diagnosis should precede installation. Concealing an incorrectly identified problem may leave moisture continuing elsewhere within the construction.

Q) Does Platinum PM3 protect finishes from salts and contaminated walls?

A) Platinum PM3 creates a physical barrier that separates supported finishes from damp, efflorescent salts, alkalis and common contaminants held within masonry. This helps prevent staining, salt crystallisation and moisture from transferring directly into plasterboard, timber sheeting, flooring or an internal block lining. The membrane is particularly useful where removing every trace of historic salt contamination would be impractical. It does not neutralise salts or make an unsafe background harmless. Heavy chemical contamination, unknown industrial residues, oils or hazardous substances require specialist investigation before enclosure. Any loose, unstable or organic material must also be removed. Successful isolation depends on maintaining continuity at sheet joints, corners, fixing points, service penetrations, wall bases and terminations so the protected finish never bridges back to the affected substrate.

Q) Can Platinum PM3 be used below ground for waterproofing?

A) Platinum PM3 can be incorporated into a properly designed Type C drained protection system on suitable below-ground walls, floors, tunnels and sloping vaulted structures. In this arrangement, the membrane does not attempt to resist hydrostatic pressure as a standalone barrier. Water entering through the retaining structure moves within the studded cavity towards Platinum AquaTrack drainage and then to a dependable gravity outlet or AquaSump arrangement. The route must be continuous, accessible and sized for the assessed water risk. Sealed fixings, correctly detailed joints, inspection points, pumping resilience and planned maintenance are essential. Complex, habitable, high-risk or warranty-controlled projects should be designed by a competent waterproofing specialist in accordance with BS 8102:2022 and coordinated with the structure and internal finishes.

Q) Can Platinum PM3 help create a habitable Grade 3 basement?

A) Platinum PM3 can contribute to a Grade 3 internal environment, where water penetration and dampness are unacceptable, when it forms part of a complete Type C system designed for that performance. The membrane alone cannot guarantee a habitable basement or environmental grade. Success also depends on the retaining structure, groundwater assessment, AquaTrack layout, outlet or sump capacity, pump redundancy, alarms, backup provisions, accessible maintenance and workmanship. Habitable accommodation additionally needs coordinated insulation, heating, ventilation, condensation control, fire safety, electrical design and suitable wall and floor finishes. Any failure with serious consequences may justify twin pumps, high-water alarms and backup power. A waterproofing designer should coordinate these measures and provide drawings, inspection requirements, testing records and a maintenance schedule for the building owner.

Q) Can Platinum PM3 be installed on walls and floors?

A) Platinum PM3 is suitable for compatible wall and floor applications, although each surface requires a different installation method. On walls, the studs face the substrate and the sheet is secured mechanically using fixings selected for the background and exposure. The room-facing surface then receives a protected, mechanically supported or independent lining. On floors, PM3 is loose-laid with the studs facing down over a stable, suitably level base; it must not be punctured by floor fixings. Adjacent floor sheets are closely butt-jointed and sealed before a compatible load-distributing build-up is installed. Where walls and floors meet below ground, both cavities must connect correctly with the AquaTrack collection route. Junctions, final levels, insulation, loading and drainage should be designed before any membrane is cut.

Q) Can Platinum PM3 be fitted to vaulted or sloping soffits?

A) Platinum PM3 may be fitted to suitable arched, vaulted or sloping retaining soffits where the entire construction provides a dependable minimum 10% fall towards the designed drainage point. The studs face the substrate, and sufficiently frequent, separately sealed fixings prevent sagging, folds or pockets that could collect water and debris. Section joints are formed as close butt joints sealed centrally with 150mm Platinum Corner Tape. The soffit membrane should turn down each end wall by at least 200mm, with the wall membrane fitted in front to preserve the drainage path. Flat retaining soffits are unsuitable because water could pond behind the sheet. Complex vault geometry should be surveyed and detailed by a competent waterproofing specialist before installation.

Q) Which substrates are suitable for Platinum PM3?

A) Suitable backgrounds can include sound concrete, brick masonry, concrete blockwork, compatible stonework and stable, well-bonded render. Below-ground floors require a stable, suitably level concrete base or compatible repaired slab capable of supporting the complete floor construction. The substrate must be structurally sound enough to hold the selected fixings without excessive movement or pull-out. Weak, friable or low-density above-ground masonry may accept a compatible specialist fixing, but this does not replace necessary repairs. Loose plaster, hollow render, crumbling mortar, sharp projections and unstable materials must not remain concealed. Active structural movement, significant cracking, timber decay or hazardous contamination requires investigation before PM3 is installed. The final decision should reflect the exposure, lining loads, drainage design and condition of the actual substrate.

Q) How should a surface be prepared before installing Platinum PM3?

A) Remove loose debris, dust, organic matter, sharp projections and unstable material so Platinum PM3 can sit evenly without being punctured or bridged. Existing plaster should normally be removed because moisture can soften it and weaken mechanical fixings. Sound, well-bonded render may remain if it is sufficiently flat and secure, but loose, hollow or crumbling areas must be taken off. Brush away mould or fungal growth and apply an appropriate treatment where required. Wet rot or dry rot needs assessment and remediation by a competent specialist. Repair significant holes and defective joints, investigate structural cracks and correct avoidable leaks. Below ground, concrete may also need a compatible anti-lime treatment to reduce deposits that could obstruct the shallow cavity or drainage channel.

Q) How is Platinum PM3 installed on an internal wall?

A) Plan whether horizontal or vertical installation will minimise joints and simplify corners, reveals and lining supports. Cut Platinum PM3 using a sharp utility knife, scissors or shears, then place it with the studs facing the wall and the flat face towards the room. Keep the sheet level and tight into changes of direction without stretching or crushing the profile. Where practicable, continue it into the ceiling void and below the finished floor level; otherwise terminate tightly at the soffit and floor rather than leaving deliberate ventilation gaps. Fix into sound substrate using the specified membrane plugs and add fixing points where battens, brackets or wall ties will require support. Complete and inspect all joints, edges and penetrations before installing finishes.

Q) Which fixings should be used with Platinum PM3?

A) Platinum Waterseal Brick Plugs With Seals are the primary wall fixings for suitable sound brick, blockwork, concrete, stone and masonry, particularly where sealed fixing continuity is required. Drill with a 10mm masonry bit to achieve the necessary embedment, keep holes square and seat each washer evenly without crushing the studs. Use enough plugs to hold PM3 neatly, then add planned fixing rows for timber battens, dry-lining brackets or wall ties. Compatible Platinum Cob Plugs may be considered for weak or friable above-ground backgrounds where a standard plug cannot grip reliably, but they are not a substitute for substrate repair or a designed below-ground fixing. Overhead work requires separately sealed fixings. Never introduce casual screws through the membrane after installation.

Q) How are joints sealed between Platinum PM3 sheets?

A) Platinum PM3 has no flange, so adjoining sheets must meet edge to edge as a close butt joint rather than being overlapped. Clean and dry both room-facing surfaces, align the edges without gaps, then centre 150mm Platinum Corner Tape over the joint so approximately equal widths adhere to each sheet. Remove the release liner progressively and press or roll the tape firmly across its complete width and length. The seal must remain fully supported, uncreased and continuously bonded. Dust, condensation, grease or cold surface moisture can weaken butyl adhesion, so prepare the membrane carefully and gently remove surface moisture where necessary. Standard wall and floor joints use this same face-applied method, with project-specific detailing at junctions, penetrations and complex shapes.

Q) How should corners, returns and window reveals be detailed?

A) Plan corners and reveals before cutting so the membrane can follow the geometry with the fewest joints. Take Platinum PM3 firmly into internal and external corners, forming neat square creases without leaving unsupported bridges or crushing the studded cavity. Continue onto return walls where necessary to stop moisture and salts bypassing the treated area. If the wall contour causes the sheet to distort, stop at a controlled position, cut cleanly and start again with a new close butt joint sealed centrally using 150mm Platinum Corner Tape. Three-dimensional or irregular details may require compressed Platinum Waterseal Rope and a compatible membrane patch. Keep every sealing surface clean and dry, preserve the drainage path and inspect vulnerable corners before they are concealed.

Q) How are pipes and services sealed through Platinum PM3?

A) Keep pipes, cables, conduits, sockets and controls on the protected side of Platinum PM3 wherever practical, because every penetration creates a possible route for dampness, salts or water. Where a service must pass through, cut the smallest neat opening that allows installation without tearing or distorting the sheet. Fill the remaining annular gap with firmly compressed Platinum Waterseal Rope, then add a compatible PM3 patch sealed with Platinum Joint Sealing Membrane Tape or Corner Tape where the shape requires additional protection. Allow for pipe movement, vibration, heat and future replacement rather than creating a brittle detail. Service routes should never block AquaTrack or interrupt the cavity. Photograph completed penetrations and test below-ground drainage before the lining hides them.

Q) How should Platinum PM3 connect to AquaTrack at floor level?

A) In a below-ground Type C system, the wall-to-floor junction must allow water from behind Platinum PM3 to enter Platinum AquaTrack without passing into the protected floor construction. Position the membrane and channel upstand to the approved project detail, keeping all drainage openings clear of tape, mortar, drilling dust and insulation. Where PM3 continues across the floor, connect the wall and floor sheets or channel upstand using the specified combination of 150mm Platinum Corner Tape and compressed Waterseal Rope. Avoid bunched membrane, unsupported seals and crushed studs at corners. AquaTrack must continue to a lawful gravity discharge or correctly sized AquaSump arrangement and retain accessible inspection points. Flush and test the complete route before wall boards, screed or flooring conceal it.

Q) How is Platinum PM3 installed across a floor?

A) Install Platinum PM3 over a clean, stable and suitably level concrete base with the studs facing down. The membrane remains loose-laid and must not be punctured with floor fixings. Plan sheets around columns, thresholds, channels, sumps and services, then form close butt joints sealed centrally with 150mm Platinum Corner Tape. Protect completed areas from traffic, tools, rubble and sharp objects. A compatible floor build-up may include tongue-and-groove board within an approved floating construction, or properly designed concrete or screed. Current guidance allows at least 50mm reinforced concrete or screed directly over PM3, or at least 65mm over compatible insulation, subject to structural loading, reinforcement, drainage, insulation, levels and the final use being checked together.

Q) Can plaster, render or dot-and-dab boards be applied to PM3?

A) No. Platinum PM3 is non-meshed and does not provide the mechanical key required for direct plaster or render. Dot-and-dab plasterboard adhesive must not be used on its smooth surface either, because it cannot create a reliable supported lining and may bridge dampness or salts from the background. Choose treated battens and securely fixed boards, an independent dry-lining frame, a compatible wall-supported system or a properly restrained internal masonry lining instead. If a directly plastered finish is essential, specify a purpose-designed meshed damp-proof membrane and its compatible plastering system rather than modifying PM3. Final finish selection should be made before installation because it determines plug rows, brackets, service positions, insulation, fire protection and the space required in front of the membrane.

Q) Does Platinum PM3 require curing or drying time?

A) Platinum PM3 itself requires no curing period because it is a prefabricated HDPE sheet installed mechanically on walls or loose-laid on floors. Once the membrane, joints, fixings, drainage connections, penetrations and repairs have been inspected and tested, the specified protected finish can normally proceed without waiting for the sheet to dry. This can shorten refurbishment programmes compared with some wet-applied barriers. Other products used within the project still require their own curing or drying conditions. Repair mortars, screeds, concrete, biocides, anti-lime treatments, adhesives and sealants must reach the state required by their instructions. Butyl tapes and Waterseal Rope also need clean, dry contact surfaces; moisture, condensation, dust or contamination must not be trapped within a seal.

Q) What are the main technical specifications of Platinum PM3?

A) Platinum PM3 is manufactured from HDPE with a 0.6mm sheet thickness, 3mm stud height, 20mm stud centres, 2.19litres/m² air-gap volume and 500g/m² unit weight. It passes watertightness testing at 60kPa for 24 hours under EN 1928, while water-vapour resistance is above 3020MNs/g. Tensile strength is 416N in the machine direction and 488N across the sheet. Resistance to static loading exceeds 20kg, and compressive strength is 250kN/m². The stated working temperature range is -50°C to +80°C, with a softening temperature of 126°C. Reaction to fire is Class E. These values describe the membrane rather than the performance of the complete wall, floor or waterproofing system.

Q) Which standards and declarations apply to Platinum PM3?

A) Platinum PM3 is declared as a Type V flexible damp-proof sheet under BS EN 13967:2012+A1:2017. Its declared watertightness is assessed to EN 1928, tensile performance to BS EN 12311-2, static loading to BS EN 12730 and compressive strength to BS EN ISO 25619-2. The reaction-to-fire classification is Class E under EN 13501-1:2007+A1:2009. Where PM3 is incorporated into a below-ground drained protection system, the complete design and installation should follow BS 8102:2022. These references do not mean that the membrane alone makes every construction compliant. Structure, drainage capacity, discharge, fire protection, insulation, ventilation, workmanship, maintenance and intended occupancy must all satisfy the project specification and applicable Building Regulations.

Q) How long should Platinum PM3 Damp Proof Membrane last?

A) Platinum PM3 has a life expectancy equal to that of the structure when it is correctly stored, installed, protected and used within an appropriate construction. This statement applies to the membrane sheet itself and does not automatically establish the service life of tapes, fixings, drainage channels, pumps, alarms, insulation or internal finishes. Long-term performance depends on preventing punctures, keeping the membrane protected and preserving every joint, penetration and termination. In a below-ground Type C system, channels, outlets, sumps and pumping equipment must continue operating throughout the building’s use. Rolls awaiting installation should remain upright, wrapped and under cover, away from sunlight, excessive heat, flames, sharp objects and contamination that could distort the studs or prevent dependable sealing.

Q) What maintenance does a Platinum PM3 system require?

A) The protected Platinum PM3 sheet normally requires little direct routine maintenance once enclosed, but the surrounding construction must remain undamaged and accessible where necessary. Owners should retain drawings and photographs showing membrane positions, joints, channels and no-fix zones so later contractors do not puncture concealed areas. Below-ground Type C systems require planned inspection and servicing of AquaTrack, Floor Drain Channel, inspection ports, gravity outlets, AquaSump chambers, pumps, non-return valves, alarms, backup equipment and discharge pipework. Cleaning and test intervals should follow the waterproofing design and component instructions. If dampness appears, investigate plumbing, condensation, drainage, pumps, joints and penetrations before assuming the membrane has failed. Access covers and inspection points must never be permanently concealed by flooring or furniture.

Q) What are the main limitations of Platinum PM3 Membrane?

A) Platinum PM3 cannot receive direct plaster, render or dot-and-dab plasterboard because it has no mesh key. Above ground, it isolates protected finishes but does not repair the original cause of dampness, condensation or decay. Below ground, it is not a standalone barrier against hydrostatic pressure and needs continuous, maintainable drainage and reliable discharge. The shallow 3mm cavity is vulnerable to obstruction by dust, lime, silt, mortar or crushed studs. Floor sheets must remain loose-laid, while flat retaining soffits are unsuitable. Class E applies to the membrane, not the complete construction. PM3 must not conceal unstable masonry, active structural movement, timber rot or hazardous contamination, and it requires protection from sunlight, excessive heat, flame, impact and uncontrolled penetrations.

Q) What practical tips help ensure a reliable Platinum PM3 installation?

A) Survey and design the complete detail before cutting, including sheet direction, butt-joint positions, corners, reveals, floor levels, services, lining supports and any AquaTrack route. Keep PM3, Corner Tape and Waterseal Rope clean, dry and protected throughout the work. Control drilling debris so it cannot enter the shallow cavity or drainage channel, and never overlap standard sheet joints. Fix through planned positions, compress every tape seal firmly and repair punctures before concealment. Protect floor sheets immediately and prevent following trades from crushing studs or adding unapproved holes. Before finishes are installed, inspect all joints, corners, penetrations and terminations, then flush and test below-ground drainage, pumps and alarms. Photograph critical details and provide maintenance information and no-fix zones to the owner.

Technical Data Sheet

Declaration of Performance (DoP)