Stone and slate roofs in Halifax, and the skylights and rooflights that fit them

Consent comes first

Permitted development does not apply to a listed building for a new rooflight, so the application goes in before anything is ordered. What the application needs is set out in listed building consent for a rooflight, and the general rules are in the guide to the planning and Building Regulations rules.

Choosing the unit for a listed roof

• A rooflight on the slope away from the road, kept small and set low in the roof.
• A slim frame, usually black, with a central glazing bar if the proportions need one.
• The original roof timbers left alone as far as possible, so the unit is sized to fit between them.

If there is a rooflight already

If a listed house already has a rooflight, a replacement of the same size in the same opening alters the roof far less than cutting a fresh hole. Consent may still be required, so the position is checked with the council first.

What to have ready for the council

A listed building application goes in with drawings of the roof and the proposed unit, and a short statement of why the light is needed and why the position does the least harm. The size of the unit, the colour of the frame and how far it stands above the slates are the details that matter most. Bring any earlier consents or heritage statements for the house to the survey and we can work from them.

Houses that are not listed

Some Halifax streets sit within a conservation area without any house on them being listed. An Article 4 direction can take permitted development away in such an area, and the council's planning pages say whether yours is covered. We ask the question early so the answer is known before a unit is chosen.

Stone slate against Welsh slate

Welsh slate is thin and flat, and a standard flashing kit suits it. Stone slate is thicker and uneven from one slate to the next, which leaves gaps that a kit made for thin slate would not close. On a stone-slate roof the flashing is dressed to fit by hand, slate by slate, and the courses either side are laid back to it.

Lifting and relaying

The slates are taken off in order, stacked and kept dry. A damaged one is replaced with a salvaged slate from the same roof where one is available. Because the sizes grade from large to small, the slates must go back in the same course they came from, or the pattern of the roof is lost.

Weight and the loft

Stone slate puts a heavy load on the roof timbers, so we look along the ridge and the rafters from the loft for sag or movement before choosing a position, and we keep the unit no bigger than the room needs. Where the timbers have been altered in the past, we note how and where.

Cutting through old timber

Where a rafter has to be cut, a trimmer is fixed across the opening to carry its load. Old timber can be uneven in size and spacing, so a unit sized to the gap you have avoids extra framing. The first thing the loft shows is how generous that gap is.

Inside the house

The reveal is lined, insulated around the frame and plastered, then left ready to paint. A stone house often has lath-and-plaster ceilings, so the floor below is sheeted before the ceiling is opened. Old plaster crumbles when it is cut, and we clean the rooms before leaving.

Scaffold and access

Where the back wall is tall, a roof window on the rear slope needs a scaffold on sloping or stepped ground, and scaffold platforms have to be level. Where the front sits above a narrow pavement, the front slope may be reached from the road. We look at both and note the safest way to the slope you want.

Steps and yards at the back

Some hillside terraces have a back yard cut into the slope, with steps up to a retaining wall. Scaffold feet need level, firm ground, and a yard with a drop beside it may call for a longer tower or a platform built across the slope. We note the ground levels on the survey so the scaffold is planned in advance.

Deliveries

A steep one-way street or a terrace with a back path is awkward for a van, and a long box such as a roof window frame has to be carried by hand. We look at how a unit reaches the house when we survey, in the same visit as the roof.

Escape heights on a sloping site

A bedroom in the roof of a hillside terrace may stand higher above the ground at the back than the front. Approved Document B ties an escape window to its height above the ground outside, so the same attic can be on one side of the line at the front and on the other at the back. We refer to that document on the survey; the numbers are in it.

Weather on an open slope

On some slopes the rear roof faces down the valley and is open to the weather from that side. The flashing laps are checked with that exposure in mind, and the frame is fixed to sound rafters on both sides of the opening. Stone slates are heavy to move, so the ones lifted for the work are stacked in course order on the scaffold or in the yard until they go back.