Skylights & rooflights in Petworth

What failure looks like

The clearest sign is misting. A rooflight is made of sealed glass, with a gap between the panes, and when the seal at the edge lets go, moisture gets in and leaves a cloudy film that cannot be wiped off from either side. There is no way to reseal it. The honest answer is to assess the unit and replace it. Our misted and failed rooflights page sets out the signs to look for.

Other signs are less obvious. A window that sticks, a frame that has split at the corners, a stain on the ceiling after heavy rain, or a draught that moves a curtain on a still day all point to a unit near the end of its life. In older houses with timber frames, rot at the sill or the head of the unit is another warning, and we look closely at the timber around the opening when we are on the roof.

Age brings a second problem that has nothing to do with the glass. Units fitted decades ago were built to the standards of their day, and the thermal performance of a single-glazed or early double-glazed roof window is well below what is available now. You feel it as a cold patch under the window in winter and a warm one in summer. When a unit is already due for replacement, that is the moment to choose a better one rather than fit the same thing again.

The sash also deserves a look. Opening units that have been used for years can lose their balance, so that they drop shut or will not stay where they are put. A friction hinge that has worn out is a safety matter as well as a nuisance, since a heavy sash coming down on someone leaning out to reach a catch is the kind of accident that a new unit removes.

What a swap involves

Replacing a unit is more than lifting one out and dropping another in. The flashing around it has to be taken apart and rebuilt, the surrounding tiles or slates need to be lifted and relaid, and the opening needs to be checked for rot or movement. A new unit set into a damaged surround will fail faster than the old one did, so the survey spends its time on the surround.

Signs on an old unit and what we look at

Sign	What it suggests	What we check
Cloudy glass	Failed seal	Unit and frame
Stained ceiling	Water at the edge	Flashing and surround
Stiff or stuck sash	Warped frame	Hinges and timber
Cold draught	Worn seals	Frame fit in opening

Our energy efficient rooflights page shows what a modern replacement does that an older unit does not.

Larger houses present a different set of questions. The roofs are bigger, the pitches steeper and the loft space deeper, so the choice of unit widens, but the access gets harder. A high roof may call for a full scaffold, which is covered in the access chapter below.

Roof coverings are the other variable. A house in this part of West Sussex might carry clay tile, stone slate or a more modern substitute, and each one is flashed differently. We identify the covering at the survey, because the right flashing kit for it must be ordered with the unit, and an ill-matched kit can cause leaks that are then blamed on the glass.

Whatever the house, we check what lies beneath the covering before we promise a position. Our roof windows page and VELUX windows page list the sizes and how they are specified.

Where the position is sensitive, the choice of unit tends to settle itself. A slim-framed, flush-fitting rooflight that sits close to the roof plane is the easiest to defend, and our conservation rooflights page shows what we mean. If your home is listed, listed building consent is a separate matter, and we would want to know about it at the first call.

It helps to have the answers in hand before the survey. Know your address, whether the house is listed, and whether you own the freehold. Photographs of the roof from the garden and of the room from inside are useful, and so is any paperwork from earlier building work, such as a completion certificate for a loft conversion. We use these to prepare the survey, and the visit is quicker for it.

Timing matters too. A planning enquiry to a national park authority has its own timetable, and we do not predict it, so if consent is needed, the sensible order is to ask the Authority first, then book the work. We are happy to talk through the drawings we would need to give them.

For the technical inspection, the Building Regulations guide lists what is looked at.

Access in an old town can be harder than in a newer estate. Streets built before cars are narrow, houses may sit right on the pavement, and a rear garden may be reached only through the house or along a shared path. We solve this in the access plan, which goes into every quote as a written page.

The plan states the route to the roof, whether that is a scaffold in the garden, a tower on the street or a mobile platform, and names who applies for any licence. For the Petworth area, scaffold on the highway needs a licence from West Sussex County Council, and we apply. Our scaffold licence guide shows how it works. You can read how the plan is laid out on our access plan page.

The town sits twelve miles north-east of Chichester along the A285. For us the point is that delivery vehicles and scaffold lorries need a clear day and a clear approach. We agree the delivery window with you, and tell you when to move cars from the frontage so that the vehicle can stand where the plan says it will.

Gardens at the back of older properties are often long and narrow, with beds and walls that nobody wants damaged. The plan notes what gets protected, how materials are carried through, and where waste is stacked. A good access plan is dull to read because every awkward point has already been dealt with.

The running order

1. Survey. We look at the street, the roof and the loft, and decide on the route up.
2. Licences. We apply for any scaffold licence or parking suspension the plan calls for.
3. Neighbours. Notice goes to the people on either side before the scaffold goes up.
4. Work. The old unit comes out and the new one is fitted and weathered in.
5. Clear. The scaffold comes down and the road or garden is left tidy.

Where a house has been divided into flats, the roof may belong to the freeholder, so consent could be needed. Our leasehold guide tells you what to ask, but check your lease.

Think about the room as well as the roof. A bedroom wants a unit low enough to see out of from the bed or a chair, while a landing wants height and brightness more than a view. A kitchen extension benefits from ventilation, and an opening unit at the back of the room draws steam up and out. Our electric and opening rooflights page explains how those controls work.

Cost follows the size, the covering, the access and the extent of work to the surround. We cannot quote a figure without seeing the roof, but the costs page explains what moves it, and the survey gives you a fixed figure on paper. A 10-year workmanship guarantee is part of every job, and the guarantee page explains what it covers.