Roof underlay gaps

Causes

High levels of moisture causing the paper-based roof underlay to shrink

High roof cladding temperatures

Not enough lap when installed

Underlay has shrunk

Listed under: Interior, Roof, cladding, roof space, moisture, roof cladding

Cause

High levels of moisture causing the paper-based roof underlay to shrink

Repair

  • remedy the cause of the high levels of moisture (see 'Roof space dampness')
  • if the moisture problem is fixed the paper may be left as is; where some moisture remains, install roof underlay to the underside of the rafters and support with plastic tape at 300 mm centres

Back to top

Cause

High roof cladding temperatures

Repair

  • paint the roof a lighter colour to reduce temperatures 

Back to top

Cause

Not enough lap when installed

Repair

  • no easy fix – install new underlay when roof replaced

Back to top

Cause

Underlay has shrunk

Repair

  • no easy fix – install new underlay when roof replaced

Back to top