Joining membrane sheets is straightforward but requires a little care to complete a smooth finish.
150mm PS tape/strip
The membrane should be positioned so that the width of the seam is 75mm
(3”). Mark a line 5mm (1/4”) from the leading seam edge.
1) Fold the top sheet back to expose the seam area. Using a scrubbing pad apply the ClassicBond Primer to the seam area. Apply the primer past the seam edge e to the line. Primer must be dry before application of PS tapes.
NOTE: If the EPDM membrane is contaminated with dirt, etc., clean the
2) Using moderate pressure set the Seam Tape into place to keep air from being trapped under the tape and unroll the 75mm wide tape along the length of the seam, aligning the Seam Tape (not the clear backing) along the chalk line. Care must be taken not to get any bubbles or wrinkles in the tape.
3) Lay the top membrane onto the Seam Tape. Pull away the poly backing from the tape at a 45° degree angle to the seam. While removing the poly backing, draw your hand across the seam, from the back to the leading edge.
Roll the seam at right angles to the seam direction, not along it.
150mm PS Tape/Cover Strip
When butt jointing of membrane or seaming to a metal drip or similar a 150mm cover strip is used.
1) Ensure there is no gap between the membrane when butt jointing. The 150mm tape should be centrally located over the joint.
2) Apply Primer to the area to be seamed. Apply primer 80-100mm either
side of the join in the EPDM sheets.
3) Once the Primer has dried, peel back 150mm of the poly backing and
press the PS tape into the primed area. Once the tape is held in position,
peel back the poly backing and smooth the tape into the primed area. Progress along the seam.
4) Once the entire length of tape is applied to the seam, roll across the 150mm tape with hand roller. Where 150mm tapes intersect other tapes,
225mm uncured tape cover patches must be applied.