Platinum Joint Sealing Membrane Tape

Q) What is Platinum Joint Sealing Tape used for?

A) Platinum Joint Sealing Tape is used to join adjacent sheets of cavity drain waterproof membrane into one continuous waterproof layer. It is a double-sided self-adhesive butyl tape designed to sit inside membrane overlaps, flanges and stud-into-stud laps, bonding one membrane sheet directly to the next. This is important in basement waterproofing and below-ground membrane systems because the installation must work as one connected layer, not as separate sheets with weak joint lines. Platinum Joint Sealing Tape seals the joint from within the lap, helping prevent water tracking through the overlap and supporting the long-term integrity of the complete waterproof membrane system.

Q) How does Platinum Joint Sealing Tape work?

A) Platinum Joint Sealing Tape works by bonding two membrane surfaces together from inside the overlap. The tape is placed between the adjoining sheets, usually along a membrane flange, lap or stud-into-stud joint, then the second membrane surface is pressed firmly against the exposed adhesive face. Because the tape is double-sided, it grips both sheets and creates a watertight sheet-to-sheet seal along the joint line. This internal sealing method is different from covering the joint from the surface. The butyl rubber compound remains flexible and adhesive, allowing it to conform to membrane profiles, flanges and studded surfaces for close contact along the full joint length.

Q) Where should Platinum Joint Sealing Tape be used?

A) Platinum Joint Sealing Tape should be used wherever waterproof membrane sheets need to be joined together with a sealed internal overlap. Typical uses include membrane laps, flange joints, stud-into-stud laps, abutting joints, corners, reveals and wall-to-floor transition details. It can also be used where membranes have been cut, shaped or overlapped around pipes, cables, conduits, protrusions or service entries, provided a suitable lap or joint can be formed. Its purpose is to maintain waterproofing continuity between adjoining membrane sheets. It is especially useful in basement waterproofing, below-ground waterproofing and cavity drain membrane installations where joint sealing is essential to system performance.

Q) What waterproof membrane systems can Platinum Joint Sealing Tape be used with?

A) Platinum Joint Sealing Tape is designed for use within the Platinum Waterproof Membrane System, where it provides the primary jointing method for cavity drain membrane sheets. It can also be used with compatible Newton CDM, Platon and Wykamol waterproof membrane systems where a double-sided butyl jointing tape is required. This makes it a practical option for installers working across different cavity drain membrane ranges, especially when a reliable sheet-to-sheet bond is needed within an overlap. Compatibility should still be considered against the specific membrane surface, system design and site conditions. The tape must be applied to clean, dry membrane surfaces and pressed firmly to form a dependable seal.

Q) What size is Platinum Joint Sealing Tape?

A) Platinum Joint Sealing Tape is supplied in 30mm wide rolls, available in either 15m or 30m lengths, with a thickness of 1.5mm. The 30mm width is deliberate because the tape is designed for internal jointing within membrane overlaps, rather than wide surface sealing across the face of a joint. The 1.5mm butyl thickness gives the tape enough body to compress and conform to membrane profiles, helping it maintain close contact between adjoining sheets. The 15m roll is useful for smaller detailing tasks or local repairs, while the 30m roll is better suited to larger waterproof membrane installations where multiple joints, laps and transitions need sealing.

Q) How do you apply Platinum Joint Sealing Tape?

A) Platinum Joint Sealing Tape should be applied between clean, dry membrane surfaces. The tape is positioned along the overlap, flange or stud-into-stud lap, with the backing paper removed gradually as the tape is laid into place. Once the tape is correctly aligned, the adjoining membrane sheet should be pressed firmly onto it to close the joint and complete the bond. Good pressure is important because the butyl needs full contact with both membrane surfaces along the entire joint. In cold, damp or humid site conditions, a heat gun is often used carefully to dry the membrane surface and assist adhesion before the joint is sealed.

Q) Can Platinum Joint Sealing Tape be used at wall-to-floor junctions?

A) Platinum Joint Sealing Tape can be used at wall-to-floor transition details where the wall and floor membranes overlap or connect and a sealed internal joint is required. Its main function is sheet-to-sheet bonding, so it should be placed inside the lap where the two membrane surfaces meet. For broader surface sealing across the corner or internal angle, Platinum Corner Tape may also be required depending on the waterproofing detail. Platinum Joint Sealing Tape is not a wide face-covering tape, so it should not be expected to replace corner detailing where a larger sealing area is needed. Used correctly, it helps connect wall and floor membranes into one continuous waterproof system.

Q) Can Platinum Joint Sealing Tape be used around pipes and service penetrations?

A) Yes, Platinum Joint Sealing Tape can be used around pipes, cables, conduits and structural protrusions where the membrane has been cut or shaped and a sealed overlap or joint can be formed. Service penetrations are important detailing points because they interrupt the waterproof membrane layer and can create weak points if not sealed correctly. The tape can be used within the overlap around the detail to bond adjoining membrane surfaces together and help maintain waterproofing continuity. For awkward or irregular penetrations, careful cutting, positioning and firm pressure are essential. Wider surface tapes, such as Platinum Corner Tape, may also be required where the penetration needs additional face sealing.

Q) Is Platinum Joint Sealing Tape the same as Platinum Corner Tape?

A) Platinum Joint Sealing Tape is not the same as Platinum Corner Tape, although both are butyl sealing tapes used in waterproof membrane systems. Platinum Joint Sealing Tape is a 30mm wide double-sided tape designed to sit inside membrane overlaps and bond one sheet directly to another. Its job is internal sheet-to-sheet jointing. Platinum Corner Tape is a wider face-applied tape used over junctions, corners, cut edges, service penetrations and wider detailing areas. In simple terms, Joint Sealing Tape seals within the lap, while Corner Tape seals over a broader surface detail. Many installations may use both products, depending on the joint, junction or membrane transition being formed.

Q) Can you plaster or render over Platinum Joint Sealing Tape?

A) Platinum Joint Sealing Tape is not designed to provide a direct plaster or render key. Its purpose is to create a watertight butyl bond between membrane sheets, not to provide a textured surface for finishing materials to grip. Where it is used with meshed membranes and a direct plaster or render finish is required, Platinum Mesh Tape should be applied over the sealed joint to reinstate the surface key. This allows the Joint Sealing Tape underneath to perform the waterproofing function, while the mesh tape provides a suitable finish-ready surface. Without this extra mesh detail, plaster or render may not bond properly over the joint area.

Q) What are the best tips for using Platinum Joint Sealing Tape?

A) The best results with Platinum Joint Sealing Tape come from clean surfaces, careful alignment and firm pressure. The membrane faces should be dry, clean and free from dust, moisture, grease and loose debris before the tape is applied. The backing paper should be removed gradually, rather than all at once, so the tape can be positioned accurately along the overlap. Avoid stretching the tape or allowing it to twist, as this can affect the contact area. Once the adjoining membrane is pressed onto the tape, apply firm pressure along the full joint length. In cold or damp conditions, carefully warming or drying the membrane can improve adhesion.

Q) What are the main limitations of Platinum Joint Sealing Tape?

A) Platinum Joint Sealing Tape should not be used as a substitute for correct membrane installation, proper lap formation or wider detailing tapes where they are required. It is an internal double-sided jointing tape, designed to sit between two membrane surfaces, not a surface-applied tape for covering large gaps, exposed edges or broad corner details. It must be applied to clean, dry membrane surfaces because dust, moisture, contamination, poor alignment or insufficient pressure can reduce adhesion and compromise the joint. It also does not provide a plasterable or renderable finish by itself. Where direct finishes, complex penetrations or wider junction details are involved, additional Platinum tapes may be needed.