Platinum UltraSeal Membrane Joint Tape

Q) What is Platinum UltraSeal Membrane Joint Tape used for?

A) Platinum UltraSeal Membrane Joint 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 that sits inside the membrane overlap, bonding one sheet directly to the next rather than covering the joint from the exposed face. This makes it especially useful for basement waterproofing, below-ground membrane installations and cavity drain systems where sheet joints must remain watertight. Platinum UltraSeal Membrane Joint Tape is suitable for membrane overlaps, flange joints, stud-into-stud laps, abutting joints, corners, reveals, wall-to-floor junctions and carefully detailed areas around pipes, cables and protrusions.

Q) How does Platinum UltraSeal Membrane Joint Tape work?

A) Platinum UltraSeal Membrane Joint Tape works by creating a direct sheet-to-sheet bond between two overlapping membrane surfaces. The tape is positioned within the overlap, with one adhesive face bonded to the first membrane sheet and the second adhesive face bonded to the adjoining sheet when the lap is closed. Because it is double-sided, the seal is formed inside the joint itself, helping prevent water from tracking through the membrane connection. The flexible butyl rubber compound allows the tape to conform to membrane flanges, laps, studs and slight surface irregularities. When pressed firmly into place, it helps create a continuous watertight joint along the full overlap length.

Q) Where should Platinum UltraSeal Membrane Joint Tape be used?

A) Platinum UltraSeal Membrane Joint Tape should be used wherever cavity drain waterproof membrane sheets need to be joined with a sealed internal overlap. Typical uses include straight membrane laps, flange joints, stud-into-stud laps, abutting joints, corners, reveals and wall-to-floor transition details. It is also suitable where the membrane has been cut, adjusted or shaped around pipes, cables, conduits, protrusions and service entries, provided a suitable overlap or joint can be formed. The tape is particularly useful in basements, cellars and below-ground rooms, where membrane joints must be sealed carefully to maintain waterproofing continuity and reduce the risk of water passing through vulnerable joint lines.

Q) What membrane systems can Platinum UltraSeal Membrane Joint Tape be used with?

A) Platinum UltraSeal Membrane Joint Tape is designed for use within the Platinum Waterproof Membrane System, where it helps join cavity drain waterproof membrane sheets into a continuous sealed layer. It can also be used with compatible Newton CDM, Platon and Wykamol waterproof membrane systems where a double-sided butyl membrane jointing tape is required. This makes it useful for installers working across different waterproofing membrane ranges, especially where a wider internal jointing tape is preferred. Compatibility should still be considered in relation to the exact membrane surface, site conditions and system design. The tape must be applied to clean, dry membrane surfaces and firmly compressed for reliable performance.

Q) What size is Platinum UltraSeal Membrane Joint Tape?

A) Platinum UltraSeal Membrane Joint Tape is supplied in 45mm wide x 9.5m long rolls with a 1.0mm thickness. The 45mm width gives a wider bonding area than narrower internal jointing tapes, while still allowing the tape to sit neatly within membrane overlaps rather than across the exposed face of the joint. This wider format can be useful where installers want a more generous sheet-to-sheet bond inside the lap, especially around flanges, overlaps, transitions and more detailed membrane work. The 1.0mm thickness provides a flexible butyl layer that can conform to cavity drain membrane profiles and help maintain close contact between adjoining sheets.

Q) How do you apply Platinum UltraSeal Membrane Joint Tape?

A) Platinum UltraSeal Membrane Joint Tape should be applied between clean, dry membrane surfaces. The tape is positioned along the membrane overlap, flange or stud-into-stud lap, with the backing paper removed gradually as it is laid into place. Once aligned, the adjoining membrane sheet should be pressed firmly onto the exposed adhesive face to close the joint and complete the seal. Full contact is important, so pressure should be applied along the full length of the overlap. 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 closed. Poor alignment, trapped dust and loose contact should be avoided.

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

A) Platinum UltraSeal Membrane Joint Tape can be used at wall-to-floor junctions where the wall and floor membranes are overlapped or connected and a sealed internal joint is required. Its purpose is to bond membrane to membrane within the lap, so it should be positioned between the overlapping surfaces rather than used as a wide face-applied corner strip. For broader surface sealing across the actual wall-to-floor angle, Platinum Corner Tape may also be required, depending on the waterproofing design and the type of junction being formed. Used correctly, Platinum UltraSeal Membrane Joint Tape helps connect wall and floor membrane sections into one continuous waterproofing layer.

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

A) Yes, Platinum UltraSeal Membrane Joint Tape can be used around pipes, cables, conduits and protrusions where the membrane has been cut or shaped and a suitable overlap or joint can be formed. Service penetrations are important detailing points because they interrupt the waterproof membrane layer and can become weak points if not sealed properly. The tape can be used within the joint around the detail to bond overlapping membrane surfaces together and help maintain continuity. On awkward or irregular penetrations, careful cutting, positioning and firm pressure are essential. Wider surface-applied tapes may also be needed where the penetration requires additional face sealing or more complex detailing.

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

A) Platinum UltraSeal Membrane Joint Tape is not designed to provide a direct plaster or render key. Its function is to create a watertight butyl bond between membrane sheets, not to provide a textured surface for finishing materials to grip. Where the tape is used on meshed membranes and a direct plaster or render finish is required over the joint, Platinum Mesh Tape should be applied above the sealed area to reinstate the surface key. This allows Platinum UltraSeal Membrane Joint Tape to perform its waterproofing role within the joint, while the mesh tape provides the correct surface for plaster or render adhesion over the membrane.

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

A) Platinum UltraSeal Membrane Joint Tape should not be used as a replacement for correct membrane installation, proper lap formation or wider surface detailing tapes where they are required. It is a double-sided internal jointing tape, designed to sit between two membrane sheets, not a broad cover tape for large gaps, exposed edges or full corner face sealing. It must be applied to clean, dry membrane surfaces, as dust, moisture, grease, poor alignment or insufficient pressure can reduce adhesion and weaken the seal. It also does not provide a plasterable or renderable finish by itself. For complex junctions, service penetrations or direct finishes, additional Platinum tapes may be needed.