A roof window can transform a dark loft, attic bedroom or top-floor landing. Fitted well, it is as weathertight as the roof around it. Fitted badly, it becomes the most likely place for water to get in. The difference lies in how the opening is formed, how the flashing is dressed to the roof covering and how the window is insulated into the roof.
We install new Velux roof windows and replace old or leaking ones, working with slate and tile roofs of all ages. We handle the roofing side of the job in full, from trimming rafters and setting the window in place to fitting the flashing kit and making good the slates or tiles around it.
Choosing the right roof window
Velux windows come in a range of sizes and opening types. A centre-pivot window rotates in the middle and suits most rooms, especially where furniture sits below. A top-hung window opens outward from the top, giving a clearer view and easier access. Both are available with different glazing, blinds and electric or solar operation.
Size and position depend on the rafter spacing, the roof pitch and where you will stand or sit in the room. Standard Velux windows are designed for pitches from about 15 degrees upwards, with low-pitch options available for shallower roofs. We measure carefully so the window sits at a sensible height and needs as few rafters cut as possible.
Flashings for slate and tile
The flashing is what keeps water out, and it must suit your roof covering. Velux produces separate flashing kits for profiled tiles, plain tiles and thin slates, as well as recessed versions that set the window lower so it sits closer to flush with the roof. Thin natural slate, such as Welsh slate, usually takes a slate flashing, while interlocking slates and concrete tiles need a tile kit.
On slate roofs, we cut and fit the slates neatly around the frame, following the kit's instructions, rather than leaving ragged edges that invite leaks. We also make sure the underlay is properly lapped to the window's collar so any water that gets under the slates is carried away.
Planning permission and building regulations
On a house in England, roof windows are often permitted development, provided they project no more than 150mm from the roof plane and do not sit higher than the highest part of the roof. Side-facing windows may need obscured glazing. Permitted development rights can be removed in some areas, and listed buildings need consent.
This matters on Tyneside, because the upper and lower floors of a Tyneside flat are separate flats, and householder permitted development rights do not apply to flats. Check with the council first, and with the downstairs owner too, as many Tyneside flat leases need the other owner's consent for structural alterations.
Building regulations normally apply because rafters are cut and trimmed and the window must meet energy standards. If the window serves a loft room, fire escape rules can affect its size and position. We will explain how the work will be approved and signed off for your home.
Replacing older roof windows
Many roof windows fitted decades ago now suffer from failed double glazing, worn seals and tired timber frames. Where the opening suits a current size, a replacement can often be fitted into the existing opening with a new flashing kit and insulation collar. Older non-standard sizes may need the opening adjusted, and we will tell you before work starts if that is likely.
Leaks around older roof windows are not always the window's fault. Debris trapped behind the top flashing, slates or tiles that have slipped against the frame, or a perished underlay collar can all let water in. We check these first, because sometimes a repair to the surrounding roof is all that is needed.
