Chimney or flue flashing has lifted

Any flashings that are no longer in their original position may lead to weatherproofing problems and should be attended to

Causes

Wind lifting flashings

Insufficient number of fixings

Movement of the flue causing the flashing to loosen

Cause

Wind lifting flashings

Repair

  • the first step is to determine whether the flashing is in good condition and can be refixed or if it should be replaced. An old flashing that is corroded, has holes in it or pieces missing or cannot be placed back in the correct position should be replaced
  • if you opt to ask a tradesperson to make the repair or replace the flashing, the work must be carried out or supervised by a licensed building practitioner. You can check if someone is licensed here
  • given the importance of ensuring that roof flashings are weathertight, you should only carry out this work yourself if you have the skills, experience and tools to do the job
  • you can find guidance for flashings, including drawings, in the Acceptable Solution E2/AS1 (freely downloadable here). Ensure all materials are compatible. In E2/AS1, Tables 20 and 21 refer to materials in contact and materials subject to runoff
  • the flashing must be appropriate for the type and profile of the roof cladding. For example, flashings for metal tile roofs are typically provided by metal tile manufacturers
  • for a flashing on a profiled metal roof, the flashing must be lapped a minimum of 250 mm beneath the roofing sheets above
  • flashings on profiled metal roofs are usually sealed with a neutral-cure silicone sealant in conjunction with mechanical fasteners
  • the fasteners are usually the same as those used for the roofing, and should include sealing washers
  • when adding new fixings to hold the flashing in place, the washer (often made from EPDM) should compress slightly when the fixing is tightened to provide a good seal against the cladding. Don’t overtighten the fixing
  • fixings for corrugated roof cladding should go through the ridge and not the trough
  • stainless steel fixings should not be used with coated steel roof cladding/flashings in severe marine and industrial environments, as they can speed corrosion
  • when using a ladder to climb onto a roof, ensure it is on a firm and level base. The base should be 1.0 metre out from the wall for every 4.0 metres of height. Secure the top of the ladder where possible
  • tell someone when you are planning to work on a roof

Cause

Insufficient number of fixings

Repair

  • as for the repair above, with additional fixings as deemed necessary

Cause

Movement of the flue causing the flashing to loosen

Repair

  • as for the first repair, but also addressing the movement in the flue
  • minimise the movement in the flue by tightening any existing stays or adding new stays