Transform Your Space: A Guide to Velux and Skylight Roof Installations

A roof-window leak may come from its flashing, an unsuitable installation detail, blocked drainage channels, condensation or a defect higher up the roof. The source should be confirmed before the window is replaced. This guide explains the practical checks a Bromley property owner should make before requesting or approving work.

Quick answer

A roof-window leak may come from its flashing, an unsuitable installation detail, blocked drainage channels, condensation or a defect higher up the roof. The source should be confirmed before the window is replaced.

How professional installation is planned

This is an overview for commissioning work, not instructions for climbing onto or constructing a roof. A competent contractor should plan access, temporary weather protection, stripping, substrate repairs, the complete new build-up and inspection of critical details.

• Confirm the existing structure and measured roof geometry
• Select a system compatible with pitch, deck, exposure and intended use
• Specify insulation, vapour control and ventilation as one build-up
• Detail eaves, verges, ridges, abutments, outlets and penetrations
• Plan scaffolding, edge protection, deliveries and waste
• Record concealed defects and agree variations before covering them
• Provide completion photographs, care information and written guarantee terms

What should be written into the quotation?

The covering name is not enough. The quotation should identify preparation, substrate, fixings or adhesives, insulation, ventilation, flashings, trims, drainage, access, disposal and responsibility for internal making good.

Treat installation as a sequence of hold points

A sensible programme pauses after strip-off and deck inspection, again after critical junctions are formed, and before completion. Photographs at those stages make hidden preparation and agreed details easier to verify.

• Pre-start specification agreed
• Substrate exposed and condition recorded
• Variations approved before covering
• Junctions photographed during construction
• Drainage and finish checked at handover

What should be inspected?

• The window model, age and roof pitch compatibility
• Flashing kit and underfelt collar
• Slates or tiles immediately above and beside the opening
• Internal condensation and ventilation
• Insulation around the reveal
• Planning, building-control and structural requirements for a new opening

Access can change the repair method

Terraced and converted properties can have different access at the front and rear. The quotation should say whether scaffold, a tower or another planned system is assumed, and how materials and waste will move without damaging occupied areas.

• Front and rear access considered separately
• Shared routes agreed before work
• Protection below the work included
• Parking and delivery assumptions recorded

Weather can stop otherwise simple work

Wind, lightning, ice and heavy rain can make access or uncovered roofs unsafe. A realistic contractor will postpone work or use temporary measures when conditions do not support the agreed safe system. The HSE roof-work guidance explains the main requirements and hazards.

Questions to ask in the quotation

• Is the water entry from rain or condensation?
• Can the flashing be repaired without replacing the window?
• Is the proposed product suitable for the roof covering and pitch?
• Who is responsible for internal making good?

Related local service

For property-specific advice, see Roof repairs in Bromley. The service page explains inspection, access and quotation arrangements.

Frequently asked questions

How should guarantees be compared?

Compare the exact work covered, duration, exclusions, maintenance duties and who stands behind the guarantee. A guarantee cannot compensate for an unsuitable specification.

Should I obtain more than one quotation?

For substantial work, comparable written quotations can help. Make sure contractors price the same scope rather than comparing totals with different omissions.

Should the quote include waste and protection?

Yes. Ask it to identify access, protection, preparation, disposal, materials, exclusions and work that can only be confirmed after opening the roof.

Discuss your roof with a local roofer

For an inspection and written quotation in Bromley, call 020 3886 3911 or email yourbromleyroofers@gmail.com. Describe the property, the roof area and any visible leak or damage. Photographs taken safely from ground level or inside the loft can also help.