Fully insured·Welwyn, Hertfordshire Mon–Sat 7am–7pm·Emergency call-outs available
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Skylight & Velux Installation

Skylight & Velux Installation, Fully Weathered In

A badly fitted roof window is one of the most common causes of new leaks. We install and flash skylights properly, so the frame stays watertight for years.

  • Fully insured tradespeople
  • 10-year workmanship guarantee
  • Rapid emergency response
  • Locally based in Welwyn

Signs you need this service

Our process

  1. 1

    Plan the position

    We confirm the right position and size of roof window for the space and rafter layout.

  2. 2

    Cut in and fit

    The opening is cut and the window fitted according to manufacturer specification — most of our installs use Velux windows and their matched flashing kits.

  3. 3

    Flash and weatherproof

    Correct flashing is fitted around the frame, which is the single biggest factor in whether a skylight leaks.

  4. 4

    Finish internally

    We can coordinate internal plastering/finishing around the new window, or leave it ready for your own tradesperson.

Why choose CS Roofing

Need skylight & velux installation?

Get a fast, free, no-obligation quote.

Frequently asked questions

Why do skylights leak more often than the rest of a roof?

Almost always due to incorrect flashing around the frame rather than the window itself — proper manufacturer flashing kits, correctly fitted, are what actually stop leaks.

Can you fit a roof window into an existing tiled roof, not just a new build?

Yes, retrofitting a roof window into an existing tiled or slated roof is one of our most common skylight jobs.

Do you fit Velux specifically, or other brands too?

We primarily fit Velux windows due to their reliability and widely available parts, but can advise on and fit other reputable brands too.

Will a new skylight need building regulations approval?

Straightforward like-for-like replacements usually don't, but new openings as part of a loft conversion typically do — we can advise on what applies to your project.

Related services

Request your free, no-obligation quote

No obligation. Your details are not sold. We usually reply the same day — urgent leak? Call now.