Internal gutters – overflows in heavy rain or strong wind

Causes

Blocked outlet(s) 

No overflows provided

There is a single outlet with insufficient capacity for water flow/rainfall

There is insufficient freeboard – more is required, based on local rainfall expectations 

Listed under: Roof, gutters

Cause

Blocked outlet(s) 

Repair

  • clear blockages

  • if blockages are cause by leaves or twigs from overhanging trees, prune back the trees so branches are clear of the roof

  • install dome-type proprietary leaf guards if blockages are an ongoing problem

  • install snowguards in areas subject to snowfall

  • don’t discharge downpipes or spreaders directly into internal gutters

  • check the gutter annually for any damage or deterioration to the lining and outlet

Back to top

Cause

No overflows provided

Repair

  • clear out gutter and install leaf guards as in previous repair

  • have a plumber/roofer form a rainwater head to the top of the downpipe. This can increase the capacity of the downpipe by slowing the water flow

  • install an overflow with sufficient capacity for the water flow

Back to top

Cause

There is a single outlet with insufficient capacity for water flow/rainfall

Repair

  • employ a plumber/roofer to form a rainwater head to the top of the downpipe. This can increase the capacity of the downpipe by slowing the water flow

  • if possible, install a second outlet or increase the size of the existing outlet.

Back to top

Cause

There is insufficient freeboard – more is required, based on local rainfall expectations 

Repair

  • if freeboard is insufficient, a major repair is necessary; consult a roofing specialist or builder about repair options

  • design requirements are set out in the Acceptable Solution E2/AS1

Back to top