Can a Roof Window Go in a Pantile Roof?

The short answer

A pantile roof takes a roof window perfectly well. Pantiles are the clay tiles with a gentle S-shaped curve, and they are common on older houses, cottages and outbuildings across the Vale of York and the east of the county. The profile is different from a flat plain tile, but the fitting method follows the same logic: a window frame, a flashing kit and a covering dressed neatly around them.

Why the curve matters

On a flat slate or plain tile, the flashing lies down against a flat surface. A pantile rises and falls across its width, which leaves a hollow under every roll. If the flashing is the wrong shape, rainwater can slip into those gaps, or wind can drive it under the edge.

That is why a pantile roof needs a flashing kit made for the profile. Makers sell these kits with soft, shaped aprons that mould over the rolls of the tile, so the edge of the flashing follows the contour of the roof. Our page on roof window flashings for slate, tile and pantile covers the differences in more detail.

How the fit goes

Because the roof is opened for the work, the roof is sealed against rain before the team leaves each evening, and the room below is covered, floors, stairs and furniture included, before the first tile moves.

Reusing the tiles you have

Old pantiles are fragile, and they weather unevenly, so they do not always come off in one piece. Some of the tiles lifted around the window may crack. Where that happens, the best fix is to use tiles of a similar colour and age, so the new area does not stand out against the rest of the roof. A reclaimed tile of the right profile usually blends better than a new one. We look at this before the work starts, so you see the likely approach in the quote, not as a surprise on the day.

The age of the roof is also worth a look. A roof that is near the end of its life is a poor place for a new opening, because lifting the tiles around it adds strain to an area that was already tired.

What we check at the survey

• The pitch of the roof, since pantile roofs can be shallow, and each window and flashing kit has a minimum pitch.
• Whether the tiles are single-lap pantiles on battens or are laid on an older lath-and-mortar base.
• The rafters where the window will go, and whether a trimmer will bear on sound timber.
• Whether the house sits in a conservation area, which can affect the choice of window.

This is also where we help pick the size and position, so that the opening lines up with the tile courses as neatly as it can. A window that fits the tiles looks right from the road.

Matching the house

A pantiled house usually has a lived-in look that owners want to protect: orange or red clay, a little lichen and a roofline that dips slightly between rafters. A roof window that sits well on that surface is one with a slim frame, a dark grey or similar colour finish and a position that follows the lines of the tiles. Placing the window so the cut tiles at its sides are whole tiles, or close to it, keeps the edges tidy.

Gutters, ridge tiles and vents are also worth a thought. A window set too close to a vent or a valley is awkward to flash, and we point out any such clash before the position is fixed.

Look for spare pantiles before work begins. A shed roof, a garden wall coping or the rear slope may carry matching ones, and taking replacements from the back keeps the front elevation uniform. Tell us if you know where any are stored.

Pantiles also hang on the batten by a nib, so each cut tile around the frame is fixed with a clip or a nail to stop it slipping in wind.

Planning and Building Regulations

On a house, a roof window in a pantile roof is usually permitted development, provided it projects 150mm or less from the roof plane and does not rise above the highest part of the roof. Our page on whether roof windows need planning permission sets out the conditions and the exceptions. A new opening also falls under Building Regulations, covering the altered rafters and the thermal performance of the glazing, and where notification applies we deal with Building Control for you.

The wider job

Pantile roofs suit a careful, unhurried fit, with the hidden work done properly and photographed for you. The finished window should look as though it has always been part of the roof. For the full process, including the survey, the written quote and the handover, see roof window installation.