Skylight Installation in Tollesbury

Tollesbury is a village at the end of its own road, set where the land runs out into the saltmarsh at the mouth of the Blackwater. There is nothing beyond it but marsh, saltings and open water, which is exactly why it has the character it does, and exactly why a rooflight here needs more thought than one a few miles inland. The wind comes in off the estuary with nothing to break it, and the air carries both salt and a persistent marsh damp that never quite dries out of a north-facing slope.

It is 24.4 miles from Ipswich in a straight line, closer to an hour on the road down the A12 and out through Kelvedon and Tiptree. It is one of the further points we cover, and the drive is part of the honest picture.

Salt and damp, not just salt

Most of the coast we work throws one main problem at a roof: airborne chloride off the open sea. A marsh village adds a second. The saltings hold water, the humidity stays high, and a slope that faces away from the sun can sit damp for days at a stretch through the winter. Salt plus permanent moisture is a harder environment for metalwork than salt alone, because corrosion needs an electrolyte, and damp salty air provides one around the clock.

That is why we do not treat Tollesbury as a marginal case. The exposure grade here is coastal, and the specification is the full coastal one.

• 316L marine-grade stainless fixings throughout. The molybdenum in 316L is what resists chloride pitting. A2, the grade in most flashing kits, pits and loses section at the point of attack, and in a permanently damp joint it does so faster.
• Marine-specification coating on any aluminium. Standard polyester chalks and lifts under salt and UV, and once water is under it at a cut edge, the marsh damp keeps it there.
• Attention to the reveal, not only the flashing. In a humid village a cold rooflight is the first surface condensation finds, so the insulation has to run right up to the frame rather than stop short of it.

Weatherboard and plain clay tile

A lot of Tollesbury’s older stock is the traditional Essex pattern: weatherboarded elevations under small plain clay tiles, double-lapped and often originally peg-hung. That covering behaves nothing like a modern concrete interlocking tile, and the flashing detail has to match it.

A plain tile is small, flat and laid in a close double lap, so there is no deep tile roll for a profiled apron to dress into. The flashing kit for it is the plain-tile variant, with a shallow skirt that seats down onto the flat tile surface. Fit a deep interlocking-tile kit to a plain-tile roof and you leave a gap that no sealant closes for long, and sealant is not a weathering detail on this coast, it is a countdown. Old plain tiles are also brittle and often laid with a good deal of camber, so we allow for breakages at survey and set the opening where the courses work rather than forcing it.

Replace rather than patch, because the marsh is patient

When a unit here starts to weep or mist, patching it is poor value. The edge seal of a sealed unit is a chemical barrier, and chloride attacks it; once it has gone, no bead of external sealant brings the seal back. In a damp marsh setting the failure only progresses faster. We replace the unit and put the fixings, flashing and upstand right at the same time, all to the coastal standard, rather than leaving one weak layer to set the life of the job.

What we usually fit here

Village daylight work is mostly a pitched roof skylight installation in the plain-tile roof, or a rear extension lit by a flat roof rooflight on a properly detailed kerb with a designed fall so water clears rather than sits. On a converted room in the roof a VELUX, Keylite or Roto unit is the usual answer, and where you want light without a cold spot the glass specification matters, so it is worth reading energy efficient skylight installation for the U-values.

What the survey looks at on a marsh-edge roof

The first thing we read on a Tollesbury roof is which way each slope faces and how much sun it sees. A north-facing plain-tile pitch at the edge of the saltings can stay wet for the better part of the winter, and a wet slope grows moss and lichen that hold yet more moisture against the tile. That matters for a rooflight because the side gutters formed by the flashing have to shed water and clear debris, and a slope that never dries is a slope where those gutters silt up with organic growth and back water up under the covering.

Inside the roof space we look for the damp signature that the marsh leaves. Old plain-tile roofs here often have no underlay, or a bitumen felt long past saving, so wind-driven damp gets into the roof void and shows on the rafters as staining and on the nails as rust weep. That is not a reason against a rooflight, but it changes the collar detail, because the new unit’s underlay collar has to be dressed into whatever secondary barrier exists and sealed properly, not just tucked under the nearest tile.

We also note the pitch. The steep plain-tile slopes typical of the older cottages shed water fast, which is a real advantage on a damp, exposed site, but the later low-pitch additions common on rear outshuts do the opposite, and a shallow slope facing the marsh holds driven rain against the flashing far longer. The covering and the pitch together decide whether a slope takes a standard unit or wants a low-pitch kit, and that is settled with a tape on the roof.

Brittle tiles and the way they were hung

The plain clay tiles on the older cottages were often peg-hung or nailed in a way no modern roofer would recognise at a glance, and a century of frost has left many of them soft at the edges and cambered out of flat. Two things follow at the opening. We allow for a proportion of breakages when tiles come off around the rooflight, because some will not survive being lifted, and we match replacements as closely as the salvage market allows so the repair does not stand out on a slope that reads clean from the lane. Where a tile has to be cut to meet the side flashing, we set the opening so the cut piece is wide enough to hold a fixing rather than balanced in place, which on a brittle old covering is the difference between a detail that lasts and one that slips in the first hard blow off the estuary.

The later stock, and where the light usually goes

Not all of Tollesbury is old weatherboard and plain tile. The village has filled in with twentieth-century houses too, on concrete interlocking tile at moderate pitches, and those behave very differently from the period cottages. A concrete interlocking tile has a deep roll and needs the profiled flashing kit rather than the plain-tile skirt the old cottages take, so the first job on any roof here is simply to identify what is actually on it. On the newer houses the demand is usually a loft conversion or light into a rear kitchen extension, and the exposure specification still holds, because a modern roof on a slope facing the saltings corrodes standard fixings just as an old one does. On the older cottages the work is more often a single unit into a bedroom or a bathroom, where the daylight matters and the reveal has to be kept warm against the marsh damp. Reading which kind of house and which kind of covering is in front of us is the whole reason we survey on the roof rather than price from the address, and on a village this mixed it changes the specification from one property to the next.

Getting a price in Tollesbury

Every job is surveyed on the roof and priced once in writing. The figure holds unless the specification changes. Installers with 25 years in the trade, a 10-year workmanship guarantee, installed to current Building Regulations.

We cover the same estuary across the water at West Mersea, and inland at Tiptree and Kelvedon. The full list is on areas we cover.

Request a fixed quote for a rooflight in Tollesbury. Tell us the roof covering and which way the slope faces, and we can say something useful before making the drive.