Newton 503 - Basement Tanking Membrane (3mm Stud)

Newton 503 - Basement Tanking Membrane (3mm Stud)

John Newton & Co. Ltd | Basement Waterproof Membranes

Newton 503 is a BBA Approved, 3mm Stud, Cavity Drain Waterproof Membrane.

Part of the Newton System 500, Newton 503 is suitable for the waterproofing of earth retained walls, vaulted soffits and floors. With its 3mm Stud, Newton 503 ideal for when space is tight, such as with stairs or low headroom.

  Newton 503 is supported by BBA Certification Certificate Number 94/3010.

Supplied in (W) 2.0M x (L) 20M - (40M²) Rolls.


Newton 503 Cavity Drain Membrane

Newton 503 is a high quality Cavity Drain Waterproofing Membrane, with a 3mm Stud, which can be used within Newton System 500, Newtons internally applied waterproofing system that includes Newton drainage and pumping systems.

Newton 503 is suitable for the waterproofing of earth retained walls, vaulted soffits and floors, is guaranteed against deterioration for 30 years, has a life expectancy of at least 50 years (DIN 9001:2000).

Newton 503 is inert and, therefore, non-polluting to drinking water, highly resistant to water, alkalies, saline solutions and organic acids, and not affected by minerals and hydro-carbons.

It is also impervious to root penetration, is rot-proof, and resistant to bacteria, fungi and other small organisms. Newton 503 also exhibits high compressive loading stability.

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.

  • Resistant to chemically aggressive groundwater, efflorescing salts and hydrocarbon contamination.

  • Rot-proof and resistant to root penetration.

Technical Data:

Membrane Material HDPE
Membrane Thickness 0.6mm
Stud Depth 2.9mm
Density 500g/m²
Vicat Softening Temperature 126°C
Service Temperature -40°C to +80°C
Compressive Strength (EN 25619-2) 320 kpa
Thermal Conductivity (EN12667) 0.461 W/mK
Water Vapour Resistance - Sd Value (BS EN 1931) >604m
Water Vapour Resistance - μ Value >1208000μ
Water Vapour Diffusion Resistance >3020 MNs/g
Resistance to Fire (BS EN 13501-1) EuroClass E
Chemical Resistance - Excellent (EN 14030) 100%
Oxidation Resistance - Excellent (EN ISO 13438) 100%




Newton 503 can be installed over a wide range of substrates in varying situations - walls, floors, ceilings, soffits, etc. However, before the system is installed, the area must be assessed to determine what preparation is required:

All timber and other organic material must be removed to prevent risk of fungal or bacterial growth behind the System, e.g. skirting boards, timber plates, old wallpaper etc. If evidence of rot exists, this must be dealt with by a specialist contractor prior to installation of the system (See our Woodworm & Dry Rot Control Products). If any mould, etc. exists, this should be cleaned off and the area sterilised with a Fungicidal Wash.

If the walls are uneven or areas have deteriorated, any large depressions should be levelled and made good to ensure a solid fixing

When assessing floor applications, consideration should be given to the type of finish that is required. The floor must be cleared of oil, loose material and any sharp protrusions and should be made level. Any holes or severe depressions should be filled. When a timber floor is preferred, then more consideration should be given to achieve a flat substrate prior to laying the membrane. This will relieve any undue movement when fitting the floor covering

The design of the drainage system should be agreed, implemented and tested before covering by the membrane. The exception to this is where Newton Basedrain is sat above the slab or raft. Flood tests should be made to check the slab or raft is flat and level prior to the installation of the Newton Basedrain, but the system can only be fully tested once the floor membrane and some form of resistance to water pressure is placed above the membrane such as temporary boards with bags of ballast or sand placed above, or the finished floor covering

When fixing the system to flat soffits you must ensure that there is a fall to create proper drainage and prevent ponding. Any sagging of the membrane should not be great enough for ponding to take place

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

Wall Application

Application on Walls:

Newton 503 should be installed by those with experience of structural waterproofing.

It is recommended that Newton 503 and its ancillary products be installed by contractors trained for the correct use and specification of the product.

Newton 503 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 Newton MultiPlug. The MultiPlug has 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.

Newton 503 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.

Newton Overtape (150mm wide) is then applied above the butted joint to join the two widths of membrane. Newton Overtape has a split backing paper, and it is easier to apply the Overtape to one roll and then the other by removing half the backing paper at a time. 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 MultiPlug without piercing the membrane, by using 5mm (size 10) self-tapping screws. Newton Multiplugs 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 with Newton System 500. 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 Newton MultiPlug 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.

Floor Application

Drainage Requirements:

When used in a full or part earth-retaining situation, the membrane system must be drained.

To comply with BS 8102:2009, you must assume that the structure will be subjected to water ingress at some time.

Newton Flooring Membranes can also be installed over the floor in above ground situations to provide isolation from damp floors either as the primary DPM or above green concrete to accelerate the contract program.

The concrete will continue to cure below the dry membrane surface allowing for floor finishes to be laid above the membrane much quicker than normal.

Methods of Drainage For Newton Floor Membranes:

The drainage must effectively remove all water from below the membrane and take the water to a point of discharge such as a sump chamber or a form of safe natural drainage. Standing water can block the membrane with silt or limescale so it is important for water to flow uninterrupted to the drainage point.

Newton Basedrain:

Newton Basedrain is placed at the wall / floor junction and collects water from behind the wall membrane and receives water at the wall/floor junction. Newton Basedrain is a designed method of removing water as it can interface with sump chambers, gullies, waste pipes etc. It can also be maintainable by inserting Newton Inspection Ports into the system.


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.

Newton 503 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.

Newton Overtape (150mm wide) is then applied above the butted joint to join the two widths of membrane. Newton Overtape has a split backing paper, and it is easier to apply the Overtape to one roll and then the other by removing half the backing paper at a time. 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 Newton Floor 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 Newton 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 Waterseal Rope, and around its perimeter with 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.


Installation to 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. Newton Nuseal Plugs with a seal made from Waterseal Rope should be used for application to vaulted ceilings.

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 Newton System 500 is 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.

The Nuseal Plug with Waterseal Rope should be used to seal the plugs.

NOTE: The Newton MultiPlug should not be used for this application as the rubber washer sold with the MultiPlug is not suitable.

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 Newton 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 Newton Overtape. Alternatively, Newton 601 Slimline 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. Services and protrusion should be collated where possible and passed through a pipe sealed with one of the Newton pipe sleeve options.

Data Sheets

Technical Data Sheet

Newton CDM Installation Manual

Declaration of Performance (DoP)

BBA Certificate

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