Correct inclination of flat glass rooflights

It is very important to install a flat glass rooflight at the correct inclination. If installed completely flat or at a pitch of less than 3 degrees rain water will sit on the glass as it will not efficiently drain off, and staining to the glass will occur.

Different rooflight suppliers have various ways to deal with this, including:

  • Fixing a dome over the glass rooflight (risk of condensation formation and dirt/dust collecting between the dome and glass layer),
  • Providing a sloped timber up-stand (unequal sight lines and costly internal finishing needed),
  • Recommending that a pitched builders kerb is created (this leaves the problem and cost with the building/roofing contractor which leads to potential costly problems with misunderstanding of dimensions).

Our aluminium framed flat glass rooflight has a unique framing detail which incorporates a 3° inclination and stepped glass edge at the sill. This means that rain water can efficiently run-off the glass and there is no "dirt trap" for water and debris to collect at, so the glass stays cleaner for longer. Our flat glass skylight can therefore be installed onto either a flat-topped builders kerb or our proprietary insulated upstand, and the optimum 3° glass inclination is guaranteed.

3° frame detail

The aluminium framework of our FE 3° glass rooflight introduces a 3 degree pitch to the glass and combined with the stepped edge glass at the sill means that rain water can run-off the glass and there is no "dirt trap" for water and debris to collect at, the glass therefore stays cleaner for longer.