Platinum CV3 Basement Tanking Membrane Kit

Platinum CV3 Basement Tanking Membrane Kit

Platinum Building Chemicals Ltd | Basement Waterproof Membrane Kit

A Basement Tanking Membrane Kit using Platinum CV3 Membrane as the choice of Membrane.

The Platinum CV3 Tanking Membrane Kit can be purchased in 20M² or 40M² Roll sizes, use the drop-down box option below to choose your preferred kit size.

The Platinum CV3 Tanking Membrane Kit is supplied with a roll of Platinum CV3 Membrane, the required number of Fixing Plugs (with Sealing Washers) and a roll of Platinum Corner Strip Tape (Overtape). An SDS Drill Bit (10mm x 160mm) is also supplied with the kit.

A full table of each Tanking Membrane Kit Contents is shown below in the 'Description' Tab.


Platinum CV3 Cavity Drain Membrane Kit

Platinum CV3 Membrane is a high quality Cavity Drain Waterproofing Membrane, with a 3mm Stud, suitable for the waterproofing of earth retained walls, floors, vaults and tunnels.

Platinum CV3 Cavity Drain Membrane is guaranteed against deterioration for 30 years and has a life expectancy of at least 50 years, delivering a Grade 3 environment to BS8102:2009 and NHBC Chapter 5.4.

Kit Contents:

Platinum CV3 Tanking Membrane Kit
Kit Size Membrane Roll Size No. of Fixings No. of Sealing Tape No. of SDS Drill Bits
20M² Kit (W) 2.0M x (L) 10M 50 x Platinum Waterseal Brick Plugs 1 Roll of Platinum Corner Tape / Overtape
(W) 150mm x (L) 10M
1 x SDS Bit
(W) 10mm x (L) 160mm
40M² Kit (W) 2.0M x (L) 20M 100 x Platinum Waterseal Brick Plugs 1 Roll of Platinum Corner Tape / Overtape
(W) 150mm x (L) 20M
2 x SDS Bits
(W) 10mm x (L) 160mm

Benefits & Features:

  • Does not require extensive and damaging preparation to the wall surface.

  • Only 3mm in thickness and so is ideal for when space is tight, such as with stairs or low headroom.

  • Speed of installation.

  • Provides vapour control and, when used with humidity control systems, is capable of delivering an environment to all levels within a Grade 3 environment to BS 8102:2009 and NHBC Chapter 5.4.

  • Creates a dry, habitable living space in areas previously suffering from damp / wet conditions.

  • Waterproof, Salt Inhibiting, Root and Contaminate resistant.

Technical Data:

Membrane Material HDPE
Membrane Thickness 0.6mm
Stud Depth 3.0mm
Density 500g/m²
Softening Temperature 126°C
Service Temperature -50°C to +80°C
Tensile Strength MD (BS 12311-2) 418 N
Tensile Strength CD (BS 12311-2) 488 N
Water Vapour Resistance >3020 MNs/g
Resistance to Static Loading (BS 12730) >20 Kg
Resistance to Fire (BS EN 13501-1) Class F
Life Expectancy Lifetime of Structure



When used in new construction, the concrete slab must be laid in accordance with BS 8204-1:2003+A1:2009 to achieve a flat surface not deviating more than 5mm from the underside of a 3000mm straight edge.

Unsound plaster, render or screed should be removed and surfaces made level, with floors to the above tolerances. This can be achieved using Universal Mortar, or a 3:1 sand:cement mix incorportating Renderproof Waterproofing Additive.

Leave all new works to dry thoroughly before any membranes are fixed.

In case of walls suffering from mould or masonry fungi, prior to fixing the membrane, remove surface contamination by brushing, then apply a Masonry Biocide in line with the relevant Technical Data Sheet

If Dry Rot (Serpula Lacrymans) is present in the walls, this will require detailed assessment before proceeding. 

Above ground level it is recommended, that where possible, all sources of moisture are alleviated at the source using a DPC such as DampSolve, before applying Platinum CV3 Membrane. This reduces potential damage to masonry and timber etc.

New concrete should be treated with Platinum Lime Inhibitor which prevents free lime from the curing concrete being drawn out by ingressing water.

Application on Walls:

Platinum CV3 should be installed by those with experience of structural waterproofing.

It is recommended that Platinum CV3 and its ancillary products be installed by contractors trained for the correct use and specification of the product.

Platinum CV3 is fixed with the studs against the wall to create an air / depressurisation gap.

The membrane can be fixed either vertically or horizontally. When making this decision, you will need to take into account the size of the area to be lined, and the height of the walls relative to the width of the membrane. 

Horizontal fixing requires less cuts and jointing but the full roll is very heavy at first. Vertical fixing has much lighter strips to fix, but requires that each of these is taped back together again. You may find that vertical fixing is easier, but requires more Waterseal Tape or Overtape for jointing.

The membrane is fixed to the wall with the Platinum Waterseal Brick Plugs (Supplied). These plugs have a soft rubber sealing washer fitted to the plug for sealing to the wall membrane.

Place the membrane in position as level as you can judge by eye. Using a 10mm drill bit, drill through the centre of a stud near the top and edge to a depth greater than the fixing.

The fixing is then hammered into the pre-drilled hole until the plug sits flush in the stud. The rubber washer re-seals the hole. Level the membrane using the spirit level or laser level if used, and fix another plug about 2 metres along at the top of the sheet. The membrane will now be hanging level to the wall.

If you are fixing horizontally, continue fixing every 2 metres until you have reached the end of the roll or you have covered all of the wall(s) to be treated. It is very important to regularly check the level. If the membrane is not level, you may well find that the membrane is kinked and looks unsightly, it will also dive down when fitted around corners.

If you are fixing vertically, hang each subsequent sheet by the two fixings as described above.

Platinum CV3 does not have a flange, so a butted joint is used.

Starting at one side of the room, unroll the membrane with the studs down. The next membrane width is rolled out so that edges of the two rolls meet at a ‘butt joint’. Clean both edges.

Platinum Overtape (Supplied) is then applied above the butted joint to join the two widths of membrane. This process is repeated until all areas are covered.

Apply more pressure with the palm of your hand to further seal the whole of the joint. A Hot Air Gun should be used to help sealing, especially in cold or damp conditions.

Fixing Centres:

Once the wall membrane is hanging from the top fixings the rest of the fixing plugs need to be fixed.

The spacing of these fixings is dependant on the type of wall finish to be used:

  • Timber Battens - 600mm centres vertically and 400mm horizontally.

  • Barrel Vaults - Tighter centres 300mm around the vault and 600mm down the vault.

  • Fixed Metal Track (Gypliner) - 800mm centres vertically and 600mm horizontally.

  • Brick or Block Walls restrained to the retaining wall using ties should have the fixings at centres to provide the correct number of restraints at the correct centres.

  • Free standing timber and metal frames and free standing block walls do not require specific fixing centres. In these cases use sufficient fixings to ensure the membrane is neat and tidy and reasonably tight to the wall, especially around corners and reveals.

  • When fixing the system to vaulted soffits you must ensure that enough fixings are used to keep the wall membrane tight to the soffits with no sagging.

  • All fixings should be in line both horizontally and vertically.


Battens should be pre-treated and of a minimum dimension of 25mm x 38mm although you may find that 25mm x 50mm offers better fixing at the edge of the plasterboard.

The battens can be fixed into the Waterseal Plugs without piercing the membrane, by using 5mm (size 10) self-tapping screws. Platinum Waterseal Plugs will take 30mm of screw, so be sure to purchase the correct length for the thickness of batten.

Over-tightening of over length screws can loosen the plug. Be very careful not to puncture the wall membrane when drilling and fixing the battens. Battens should be fixed so that all plasterboard edges are supported. Use a Timber Treatment to protect cut battens.

Once the battens are fitted into position, plasterboard can be fixed to them using clout nails or preferably plasterboard screws. Care should be taken not to exceed the depth of the battens with the screws, and thereby puncture the membrane.

Alternative Fixings:

Other finishes may be employed depending on the requirements of the specifier.

Free Standing Frame:

This method should be employed if the wall is undulating, as with some stone structures or where space loss is a secondary consideration. The frame would be fixed to the soffit and the floor finish with the supplied ‘U’ channels.

With the increasing requirement of insulation to meet Part ‘L’ of building code, the use of these frames is becoming more popular, the thickness of insulation required is often in excess of the thickness of the frame, and so the use of these frames does not add extra depth to the wall build when using this method.

Because the frame is free standing and has no relationship with the wall membrane, very few fixings are required and so this wall finish above allows for the fastest and most efficient method of fixing Newton 503 to the wall.

Proprietary Fixing Systems:

Fixing systems such as Gypliner or Lafarge can be used. It is also possible to use metal profile systems when constructing new internal walls.

Internal Block Walls:

If preferred the system can provide a water and vapour proof barrier, and then be lined with a block or brick inner skin. Special ties are available that fit into the Waterseal Plugs for lateral restraint of the internal wall. The ties and retaining clips can also be used for the fixing and holding in place the wall insulation.

Application on Floors:

Starting at one side of the room, unroll the membrane with the studs down and cut to fit the room as one would a carpet.

Platinum CV3 does not have a flange, so a butted joint is used.

Starting at one side of the room, unroll the membrane with the studs down. The next membrane width is rolled out so that edges of the two rolls meet at a ‘butt joint’. Clean both edges.

Platinum Overtape is then applied above the butted joint to join the two widths of membrane. This process is repeated until all areas are covered.

Apply more pressure with the palm of your hand to further seal the whole of the joint. A Hot Air Gun should be used to help sealing, especially in cold or damp conditions.

Seal the Platinum CV3 Membrane to the up-stand of the Newton Basedrain perimeter drainage channel with Corner Strip / Overtape. Use a heat-gun to dry the membrane surface and to assist with the bonding of the tapes.

Where the floor membrane is required to be jointed to horizontal DPC’s, such as DPC Roll, through internal and external walls, these joints should be sealed with Platinum Waterseal Tape. Ensure both surfaces are clean and dry before attempting to make these joints.

If there are any services through the floor, the membrane can be cut and trimmed around them, and the gap filled and sealed using a high quality MS or SMX Polymer Adhesive. If necessary, a patch of membrane or Damp Proof Course (DPC) is laid over and sealed to the service with Platinum Waterseal Rope, and around its perimeter with Platinum Waterseal Tape. It should be noted that protrusions through the floor slab / raft should be avoided wherever possible as they create weaknesses that allow unnecessary water ingress.

The specified floor finish can now be laid directly over the floor membrane, which must not be punctured by any fixings through the floor. When a timber floor finish is preferred you must allow an expansion gap around the wall edge.

Speak to the supplier of the floor finish to confirm the correct size of this expansion gap.

Fast Track Application of Floor Finishes:

Following the installation of new concrete slabs and screeds, it is normal to expect lengthy drying periods before floor finishes can be applied.

The membranes can be laid onto green concrete as soon as it is ‘walkable’, allowing instant application of floor coverings without reference to RH levels.

The construction moisture is controlled in the air gap.

Application on Vaults:

A ceiling which is to be covered, as in a vaulted cellar construction, should be fixed and lapped in such a way so that water does not pond behind the system.

The laps and joints should also be detailed correctly to allow correct drainage, and prevent water from sitting on joints. Use Waterseal Plugs (Without the Rubber Sealing Washers) but instead with a seal made from Waterseal Rope for application to vaulted ceilings.

NOTE: The Rubber Sealing Washers should not be used with the Waterseal Plugs for this application as the washers are not suitable for this purpose.

Where flat soffits are being considered it is imperative that they should have a fall in line with drainage requirements.

Again, sagging of the membrane should be avoided to prevent ponding.


Where these membranes are to be installed in vaulted cellars, our experience shows that the best method of application is as follows:

Measure the depth of the vault from front to back wall and allow for a down turn at each end of 200mm. Unroll the sheet and cut to size.

Estimate the approximate centre of the arched ceiling and mark it. Measure down the arch 1.2 meters from there and again mark it. Strike a horizontal line along the wall from back to front. This will give you a guide line for your sheet edge as you fix it along the length of the ceiling, thereby keeping your sheet sections symmetrical. You may wish to hammer in masonry nails to the guide line to give a physical edge to the guide line.

Offer up your first section of membrane to the ceiling allowing a lap to the back wall of 200mm. Using your guide line to keep the sheet square, drill and fix the sheet along the apex of the arch following the same line of studs.

Again, the Waterseal Plug (Excluding the Rubber Seals) with Waterseal Rope should be used to seal the plugs.

The fixings should be fixed through the centre of the membrane studs at approximately 600mm centres.

It should be remembered that the plugs provide the fixing points for your battens; therefore they should be kept in line.

Your next section of membrane is again cut to size allowing a 200mm lap at each end. Before offering up the next sheet, a Waterseal Tape joint should be applied to the edges of the first sheet, either on the flanged edge or between the last two rows of studs on the none-flanged edge.

With the protective paper left on the tape you can now offer up the next sheet ensuring that you use the flanged edge to overlap onto the sealing tape.

Once you have the second sheet positioned correctly over the sealing tape, remove the protective paper working out from the middle and effect a seal.

You can now carry on fixing the sheet as previously described. This process is repeated until you have covered the arched walls to the springer and the vertical walls below the springer, maintaining a 200mm lap to the end walls.

Vaults - End Walls:

At the end walls of the vaulted construction an ‘end piece’ of flat membrane is fitted to the end wall of the vault. The 200mm lap from the soffit membrane is cut in fans to fit the curve and sit neatly against the wall, filling each cut with a small piece of Waterseal Rope or Waterseal Tape. Do not make the cuts all the way up to the ceiling and make as few cuts as possible.

Measuring the highest point of the arch, the ‘end piece’ membrane is cut to size and fixed to the end walls in front of the fanned ceiling membrane. The membrane is then trimmed to fit neatly into the curve of the ceiling.

The end wall membrane is then pulled back at the sides and around the arch to expose the studs on the reverse side.

Using Waterseal Rope, a joint is made by the same method at the stud / stud joint details, with the exception that around the arch the rope should follow the contour of the ceiling curve.

Door Reveals:

When you fit the CV3 Membrane to the end wall with the door opening, please bear in mind that you will have to fit a section of membrane around the door head and lapped down the sides by approximately 100mm.

You can then wrap the wall membrane around the sides, maintaining the correct drainage detail and forming an overlap.

This application detail will produce a small gap on the angle of the door opening.

This should be sealed using Platinum Overtape. Alternatively, a slim Flooring Membrane such as Newton® 601 Slimline Membrane or Platon® Stop Membrane can be used a flat DPC in lieu of the studded membrane if space is limited.

Overhead Intrusions:

Where service pipes, electrical wiring or other intrusions occur overhead or around the arch, these should be re-sited to a vertical surface where they can be better sealed and re-situated on the dry side of the system.

Most services can be concealed between the battens.

Data Sheets

Technical Data Sheet:

 Coming Soon

Declaration of Performance (DoP):

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