VELUX Window Installers › Cardiff › Guide
Yes, in most cases. Adding a roof window means cutting an opening in the slope, so the structure behind it matters as much as the covering. In Cardiff we fit VELUX and similar roof windows into slate and tile roofs on terraces, villas and semis. The answer always comes from a look at the actual roof, not from the street.
What decides whether it will fit
The main points are the pitch, the rafter spacing, the roof covering and what sits near the spot you want. A chimney stack, a valley or a purlin close to the opening can rule out one position and still leave another. Many Victorian terraces in Roath and Cathays have good head height under the slope, which helps a lot.
What we check in the loft first
From inside we look at the rafters, any purlins or struts, the insulation and the room you want to light. We check the position will give a useful view and a safe way through to the window. The opening usually needs rafters trimmed and doubled up around it, which we confirm on site before we agree a plan.
- Rafter size and spacing across the planned opening.
- Purlins, struts and wall plates near the opening.
- Chimney stacks and valleys close to the position.
- Insulation and ventilation in the roof space.
Matching the window to the roof covering
A roof window has to be matched to a flashing kit made for the covering, whether that is natural slate or concrete tile. The wrong kit lets water in at the edges. On the slate of an older Cardiff terrace the flashing is a different job from the one on a 1930s semi's concrete tiles, so we choose the kit to suit the roof.
The work inside the room
Inside, the opening is lined, insulated around the frame and finished with a vapour control layer so the room stays dry and warm. The lining gives a neat splay of daylight into the room. A roof window does not need to be a mess indoors, and we plan the finishing along with the cutting.
Planning and what to expect
Some roof windows may need planning or Building Regulations checks — we advise before work starts. A front slope in a conservation street is more likely to raise questions than a rear one. We open the roof in a controlled way, keep it sealed up between visits and tell you each stage before it happens.
- Rear slopes are usually simpler than front ones.
- Front slopes on some streets may need extra checks.
- We seal the opening whenever we leave the site.
- We tell you each stage before it happens.
Need velux window installers in Cardiff? See our velux window installers in Cardiff page, or call 07766 547309.
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Common Questions
Does adding a roof window weaken the roof?
Not when it is framed properly. We trim and double up the rafters round the opening, which carries the load, and we confirm the details on site. Cutting a rafter with no support would be a problem, and we do not do that.
Which slope is best for a roof window in Cardiff?
Usually the rear slope, which is out of sight from the street and often gets more sun. The right slope depends on the room layout, the head height and the view, so we look at the loft and talk it through.
Will a new roof window leak?
A properly fitted one should not. Leaks usually come from the wrong flashing kit, poor sealing or a worn roof covering around the frame, not from the glass. That is why we match the kit to the roof and check the tiles around it.
Get a Quote in Cardiff
Tell us what the roof is doing in Cardiff and we will look at it. Call 07766 547309, message us on WhatsApp or use the form below.