How to install Flat Roof Lights

Are you looking for a high quality flat roof light or skylight for your home or project? Every flat roof light manufactured by KAT in the UK is made to bespoke sizes and is fitted with 6.4mm laminated and 6mm toughened double glazing for your security. Contact KAT for a brochure or a quote.

Contemporary Flat Roof Lights

KAT’s Flat Roof Lights should be installed with a minimum of 5 degree pitch to allow the water to run off. Every roof light is glazed with clear, toughened and laminated double glazing, offering excellent weathering properties, whilst solar control glass in either a blue or neutral tinted finish can be fitted upon request. Due to the weight, roof lights over 75kgs will be delivered with the double-glazed unit separately for glazing on site.

For a complimentary copy of KAT’s installation guide, contact KAT on 01625 439666, option 1 or email [email protected]

Contemporary flat roof light

Aluminium flat roof light

If the KATlite is unglazed then peel back the tapes in each corner before placing glass within the frame. At that point, make sure that the glass is equally spaced all round. Once you are happy with the spacing of the glass, remove the tapes carefully from the inside, taking care to ensure that the backing paper comes off properly.  Clean the outside of the glass before applying the structured sealant around the perimeter of the glazing.

Top tip: It’s a good idea to put masking tape around all the sections and the glass to make sure that the sealant doesn’t go everywhere.

Then inject the special sealant in between the edge of the unit and the aluminium frame. Tool the sealant then peel off the tapes. Do not touch the glazing until the sealant has cured, usually 24 hours. Visit the gallery of images.

Glazing specification of KAT’s flat roof lights

6.4mm low e inner pane/20mm black warm edge spacer bar/90% argon glass/6mm clear toughened outer pane.  


6.4mm laminated double glazing

Flat roof light fitted at 5 degree pitch


Flat Roof Light installation instructions appeared in Professional Builder magazine September 2017


Every KATlite Flat Roof is delivered with full installation instructions. Contact KAT for a pdf copy.   For more technical information regarding KATlite, why not visit the KAT website  or call 01625 439666 and speak to a member of the customer services team.


KAT manufactures a wide range of doors, windows and roof glazing in aluminium and pvc, all with a 10 year guarantee. Visit the website or contact KAT on 01625 439666.