In most cases an old roof window can be swapped for a new one of a matching size. The flashing and lining are where the care goes.
Many roof windows in Henbury homes have been up for a long time, in loft conversions and extra rooms fitted into older houses and estate homes. When one fails, the usual question is whether it can simply be swapped. Often it can, but a good swap deals with the roof around the window too, not just the window.
Why a like-for-like swap is often simple
If the opening is the right size and the rafters around it are sound, a new window of the same size can go in the same place. That avoids altering the structure, and the inside lining is often left alone. It makes for a quicker, tidier job than a new opening. If the old window was fitted well, the swap can be straightforward. If it was squeezed in or the flashing was improvised, we will find that out once it is open and tell you before going further.
When the swap gets more involved
Things change if you want a different size, if the old frame has leaked for a long time or if the timbers around it have gone damp. Rafters may need trimming and doubling up for a larger opening, and rotten timber has to be cut out and replaced before the new unit goes in.
- Wanting a larger or different shaped window
- Damp or rotten timbers around the opening
- A roof covering that has changed since the first fit
The flashing is the real work
A new window is matched to a flashing kit for the roof covering, so the water is led around the frame correctly. Reusing an old flashing is a common reason for a leak soon after a swap. We fit the correct kit and dress the tiles or slates around it with care.
What goes wrong with old windows
Most leaks around a roof window come from the flashing, the sealing, condensation or the covering around it, not from the glass. Misting between the panes means the sealed unit has failed. Knowing which fault you have helps decide whether you need a repair or a new window altogether.
- Misting between the panes of glass
- Staining around the lining or reveals
- Water tracking down the frame in heavy rain
- Draughts around the frame or a stiff opening sash
What to ask
Ask whether the replacement will be matched to the roof covering, what will be done about the lining and insulation, and how the roof will be protected from rain during the swap. Ask what happens if damp or rotten timber turns up once the old window is out. We explain all of this before work starts. Photographs of staining on the lining or ceiling help when you call.
Frequently Asked Questions
Does a new window have to be the same size?
Not necessarily, but staying the same size keeps the job simpler. A larger one means altering rafters and flashing, while a smaller one may mean extra framing. We look at what suits the roof and the room.
Can I replace just the glass?
In some cases a failed sealed unit can be replaced without a new frame, but if the frame, seals or flashing are also worn it is better to replace the whole window, and we advise on that after a look.
Will the inside need redecorating?
Often a little. Disturbing the lining and plaster around the opening can leave finishing work. Where it is a straight swap the disruption is smaller, and we tell you what to expect beforehand. We tell you honestly what to expect.
Talk to our team about VELUX and roof window installation in Henbury
Every roof is different — the fastest way to get an accurate answer is a quick chat with our team.