Rooflight and skylight installation in Winchcombe, and the covering it has to suit.

Diminishing courses on a Winchcombe slope, and what re-laying them involves

A stone slate roof has no repeating module. The slates are graded by size and laid in diminishing courses, largest and thickest at the eaves and getting progressively smaller and thinner up the slope to the ridge, so the gauge changes with every course. The old yard names for the sizes are still used, running from Cussomes at the eaves through Muffities and Wivetts to the small slates near the ridge.

Forming an opening in that means stripping the courses back up the slope from the position of the unit, setting the frame, and then re-laying downwards, re-establishing the diminishing gauge so the finished roof still reads correctly across the elevation. Get the gauge wrong on the way back down and the error is visible from the street for the life of the roof, because the eye reads the rhythm of the courses even when it does not consciously notice it. It is slow, careful work and it is the reason a Winchcombe stone roof job is priced differently from an identical unit going into a concrete tiled semi twenty minutes down the road.

Winchcombe’s Welsh slate roofs, which are easier than they look

Not every old roof in the town is stone. Welsh slate arrived in Gloucestershire in quantity in the nineteenth century when the railways made it cheap, and a good number of Winchcombe roofs were re-covered in it, along with the Victorian and Edwardian houses that were built with it from the start. From the street, under a stone gable and stone walls, it can be hard to tell at a glance.

Technically it is a much simpler roof to open. Welsh slate is a thin, regular, repeating single-lap module: slates are lifted carefully, side soakers are interleaved course by course, the head flashing is dressed under the course above, and the pitch is usually somewhere between 25 and 45 degrees. What needs watching is age and nail sickness, because century-old slates are brittle at the nail holes and corroded iron nails show up as slipped slates across an elevation. The conservation constraints still apply to the appearance, so the unit is often the same slim one, but the work behind it is faster and the price reflects that.

Holiday lets and flats over shops in Winchcombe, and working around a season

Winchcombe runs on visitors, and that shapes the client mix. Alongside houses there are holiday lets, guest accommodation, and flats above shops and cafés on the main streets. Each brings a scheduling constraint that an ordinary house does not.

A holiday let earns in the season and empties out of it, so the useful working window is often late autumn to early spring, which happens to be when the weather is least helpful. That is workable, because an opening is only started if it can be closed and made watertight the same day, and the sequence is planned around the forecast rather than in spite of it. A flat over a shop brings a different set: access to the roof may run through or over a commercial premises, scaffold on the frontage needs a licence from the highway authority and a protected pedestrian route beneath it, and the business below wants its trading hours undisturbed. All of that is agreed at survey and written into the programme, because a date that ignores it is a date that slips.

Tewkesbury Borough Council, the Cotswolds National Landscape and consent

Winchcombe falls within Tewkesbury Borough Council for planning, and the town also sits inside the Cotswolds National Landscape, the protected area formerly designated as the Cotswolds Area of Outstanding Natural Beauty. Those are two separate layers and they do different things.

Permitted development still applies to most houses, and the limit that catches people out is the projection: an alteration to the roof of a house must not project more than 150mm beyond the plane of the existing slope, and must not exceed the height of the highest part of the existing roof. That is why a flush in-plane unit is nearly always permitted development and a bulky kerb-mounted unit on a pitched slope may not be. Within a conservation area, permitted development rights can be removed street by street by an Article 4 direction, and flats and maisonettes have no permitted development rights for roof alterations at all. The only body that can confirm the position for a specific address is the local planning authority, and a written answer or a lawful development certificate before work starts is worth the modest fee, particularly with a sale anywhere in prospect. The wider position is on do rooflights need planning permission.

Winchcombe’s modern edges, where the roof is tile on trusses

Beyond the historic streets the town has twentieth century and later housing where none of the above applies. Interwar and postwar semis with hipped roofs at 30 to 35 degrees under concrete interlocking tiles, and newer estate housing on trussed rafters at 600mm centres.

On the interwar stock the covering unclips and re-lays cleanly, a manufactured roof window with its matched flashing kit is the right product, and the constraint is shape: a hip narrows towards the corner and a purlin usually crosses at mid height, leaving a clear rectangle of perhaps 1.2 metres of vertical run across two rafter bays. On the trussed stock the webs and chords stay whole, so an opening either fits the 600mm module, which suits units of 550mm wide by 780, 980 or 1180mm long, or needs a designed trimmer with the affected truss carried on it and a Building Control structural submission. Both are one-day jobs outside with the reveal and plaster following, and both are described on roof window installation.

Building Control, the two figures, and how a Winchcombe job starts

Forming a new opening is notifiable work and replacing a unit is too in most circumstances. Structure, a thermal limit of 1.4 W/m2K for a replacement roof window, fire escape at 0.33 square metres clear with no dimension under 450mm and a cill between 800 and 1100mm above the finished floor, purge ventilation at one twentieth of the floor area, and safety glazing all apply. The notification is submitted, the inspections booked, and the completion certificate comes back to the homeowner in their own name. It is the paperwork a buyer’s solicitor asks for.

Pricing runs in two stages, and on a stone roof the gap between them is wider than usual because the covering, the reclaimed material and the consent conditions all move the figure. An indicative range comes by email first, from photographs of the roof and the room, the covering, a rough size and the address, free and back within a day or two. A fixed price follows the survey and follows the consent position, itemised across unit, labour, scaffold, reclaimed stone and Building Control. That figure holds unless the scope changes at the customer’s request, or something documented as a risk in the survey notes turns out to be present. The process is on costs.

The workmanship carries a ten-year guarantee written against the four details that decide the outcome: upstand height, falls, flashing laps and their fixing pattern, and where the covering terminates and how the membrane is dressed around the frame. The roof is never left open overnight. Coverage across the county town by town is on the areas we cover pages, and work on the wolds villages east of here is described on rooflight installation in Northleach. To begin, email info@severnskylightsgloucester.co.uk with a photograph of the roof from the garden or the street, a photograph of the room from inside, and the address, because on a Winchcombe roof the covering and the conservation status are often clear from the postcode alone.