Sheet membrane roofing – lifting of sheet joints

Cause

Loss of adhesion at the joint

Repair

  • for bitumen membranes, contact a specialist to repair or replace the membrane
  • check with the roofing manufacturer before re-adhering the seam, as some adhesives are not suitable for use where the joint is continuously wet. If ponding is a problem on the roof, see 'Water ponding on membrane sheet roofing'

Cause

Expansion/contraction of the membrane 

Repair

  • for bitumen membranes, contact a specialist to repair or replace the membrane
  • check with the roofing manufacturer before re-adhering the seam, as some adhesives are not suitable for use where the joint is continuously wet. If ponding is a problem on the roof, see 'Water ponding on membrane sheet roofing'

Cause

Water has got under the membrane causing a breakdown of the adhesive

Repair

  • for bitumen membranes, contact a specialist to repair or replace the membrane
  • check with the roofing manufacturer before re-adhering the seam, as some adhesives are not suitable for use where the joint is continuously wet. If ponding is a problem on the roof, see 'Water ponding on membrane sheet roofing'

Cause

The joint is within an area where water ponds 

Repair

  • for bitumen membranes, contact a specialist to repair or replace the membrane
  • check with the roofing manufacturer before re-adhering the seam, as some adhesives are not suitable for use where the joint is continuously wet. If ponding is a problem on the roof, see 'Water ponding on membrane sheet roofing'