For help and advice call 0800 840 0565 or email

Typical Polycarbonate Roof Problems & Their Repair

Problems & Solutions

Roof Panel

Q: Panels slipping down leaving a gap at the top through which water and debris are is entering.

A: Remove panel, reposition top gasket, then replace panel and permanently secure.

Q: Panels too short or too narrow sliding out of the glazing bars leaving a gap through which water is entering.

A: Remove panels and install new ones of the correct size.

Q: Cracked or holed panel with unsightly staining and or leaks.

A: Remove panels and install new panels.

Q: Leak under the glazing bar due to failed edge gasket or blocked self draining channel.

A: Remove panel, clean out self draining channels, install new gaskets. Replace original panel.

Q: Leak due to poorly fitted, or failed house or adjacent wall flashing.

A: Remove and replace lead flashing or use specialist HTG adhesive flashing to make repair.

Q: Leak below roof vent due to failed/poor mutin bar seal above or below.

Q: Thoroughly clean the area and fit specialist HTG adhesive flashing to bridge the problem area.

Q: Leak through the roof vent.

A: Check glazing seal. If gasketted replace with Sealant.

Alternatively, fit new glazing sheet to the top of the vent with drip bars.


Q: Leak at the Rose or Spider, possibly down the cable of a light.

A: HTG adhesive flashing to form a seal around the finial/ upper rose and seal.

Q: Leak along the ridge.

A: Check integrity of the Crest for gaps Install Ridge flashing in white and seal as necessary.

Q: Leak at ridge possibly due to tracking of water along its length.

A: Check the integrity of the house interface flashing and repair as necessary.

Valley gutters

Q: Leak below or at the window below the exit of gutter.

A: Check gutter, and downspout, for blockage. Does it have limited capacity or too much water from adjacent roofs causing overflowing? Clean out blockage, install new liner to increase capacity as necessary. Re-route water from adjacent roof away from the conservatory roof.

Inspect the gutter for breaks and if found reline and seal.


Q: Leaks down the windows internally or externally.

A: Check if water is tracking under the glazing behind the gutter. If so install a drip bar to ensure that water flows directly into the gutter.

Q: Leaks to the outside of the windows.

A: Check the gutter seal and repair if necessary.

House wall interface

Q: Leaks down internal wall.

A: Check integrity of flashing. Replace or if possible repair.

Roof vent

Q: Internal leak due to the following:-

Q: Missing or inadequate external rebate for the lid to close over.

A: Modify Roof vent by fitting rebate.

Q: Leaking top or bottom seal to the glazing.

A: Install specialist flashing above and/or below seal.

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