Skylight Installation in Earls Colne

Earls Colne runs along the Colne valley with a period high street and a lot of roofs still covered in hand-made clay plain tiles and peg tiles. Some are original, some are salvaged and relaid, and almost none of them are dimensionally consistent. That is the fact that shapes skylight installation in Earls Colne more than anything else, because the proprietary flashing kit that comes in the box with a roof window is designed for a tile that does not exist on these roofs.

It is 21.1 miles from Ipswich as the crow flies, which on the road is realistically 45 to 50 minutes. Well within the patch, and worth the trip, but it is a planned visit rather than a passing one.

Why a proprietary flashing kit will not seat on hand-made tile

A flashing kit is a pressed assembly designed around a known tile. The manufacturer knows its length, camber, thickness at the tail and the exact gauge it will be laid to. The apron and side sections are pressed to suit, and on a machine-made tile that gives a repeatable weathering detail every time.

Hand-made clay plain tile gives none of those certainties. It is formed in a mould from soft clay and fired, and the process leaves variation in every dimension that matters. Tiles differ in length by several millimetres across a single pallet. They differ in camber, so the crossfall from one tile to the next is never quite the same. They differ in thickness at the tail, which stacks up across an overlap. Peg tiles, hung through nib holes rather than on moulded nibs, vary more again.

Lay that on a roof and the gauge, the exposed distance from the tail of one course to the tail of the next, moves. A roof set out at a nominal 100mm gauge will in reality run at 97mm in one bay and 104mm in another, adjusted by whoever last relaid it to make the courses come out at the ridge. Press a rigid flashing kit onto that and it bridges. Sealant will hide it for a couple of seasons and then it will not.

Lead soakers and a hand-dressed detail instead

The answer on a plain tile roof is the traditional one, and it is traditional because it works with variation rather than against it.

• Individual lead soakers at each course up both sides of the unit. One soaker per tile course, turned up against the frame and laid out under the tile, so each course weathers itself independently. The soaker does not care that the course below it sat 5mm differently.
• A dressed lead apron at the head and the sill, cut and bossed to the actual opening rather than to a catalogue dimension.
• Code-appropriate lead sized to the piece and its exposure. Soakers take a lighter code than an apron holding a dressed shape across a wider span, and lengths are kept within the limits that let lead move thermally without splitting. Oversized single pieces crack at the fixings within a few years, a slower and more expensive failure than a leak.
• Dressed by hand on site. Bossed to the tile profile, not forced.

This is the same principle a good roofer uses at a chimney on a plain tile roof, applied to a rooflight. It is the only detail that copes with a covering whose dimensions move.

Sorting and re-laying, the part nobody quotes for

Forming an opening in a plain tile roof means stripping the tiles back well beyond the opening, because plain tiles are laid double lap and you cannot cut into the middle of a lapped field without disturbing the courses either side.

Once they are off, they get sorted. Broken and delaminated tiles are set aside, because a hand-made tile that has taken frost damage will not last another twenty years. Sound tiles are sorted roughly by length, so the courses immediately around the rooflight can be laid to a consistent gauge and the flashing has something regular to work against. Salvaged replacements are matched to the existing for colour and camber, not just to the nearest reclaimed pallet.

Then it is relaid, course by course, with the soakers going in as the work rises. That takes hours it would not take on an interlocking tile, and it is the honest reason a Colne valley job carries more labour than the same unit on a modern estate.

Which units suit these roofs

Most of this is pitched roof skylight installation once the weathering is right. On the older cottages a flush conservation-style unit with a slim dark frame sits far better on plain tile than a standard high-profile window. Rear extensions usually suit a roof lantern or a flat roof rooflight instead. A modern sealed unit with a warm-edge spacer is what gets these roofs to current requirements, covered under energy efficient skylight installation.

A conservation-area high street, and the case for a flush unit

The older part of Earls Colne sits within a conservation area, and a stretch of the high street is listed, so the way a rooflight looks from the street carries real weight here even where consent is not strictly required. On a hand-made plain tile roof a standard high-profile roof window stands proud and reads as modern from the ground, which is exactly what a conservation officer objects to and, frankly, what most owners of a period cottage do not want either. The alternative is a conservation-style unit: a flush-fitting rooflight with a slim, dark, low-profile frame and often a central glazing bar, sitting down into the plane of the tiles rather than on top of them. Against hand-made clay it looks like it belongs, and on a front slope within the conservation area it is usually the only thing that will be accepted.

Most of our work here still lands on rear and hidden slopes, where a rooflight projecting no more than 150mm above the tiles and sitting below the ridge is generally permitted development outside the listed and Article 4 exceptions. But the conservation-unit choice is not only about the front. On any slope, a flush unit is the one that suits the character of a Colne valley cottage, and we tend to steer people towards it whether the planners are involved or not.

Lead is a material with rules of its own

Since the weathering on these roofs is formed in lead rather than lifted from a box, it is worth knowing that lead has behaviours that decide how long the detail lasts. It moves with temperature, a lot, expanding and contracting every day the sun touches it, so a piece that is too long or fixed at both ends will fatigue and split along a line within a few years. That is why soakers are kept short, one per course, and why an apron is sized and fixed so it can move without tearing. It is also why the code, the thickness of the lead, is matched to the piece: a soaker takes a lighter code than an apron holding a dressed shape across a wider span, and under-specifying it to save a little cost buys a crack later.

Freshly dressed lead is bright and, on a period roof, looks wrong at first. Left alone it weathers to the soft grey that reads as part of an old roof, and patination oil brushed on at the finish speeds that along and stops the white carbonate staining that otherwise streaks down the tiles below in the first wet winter. These are small things. They are also the difference between lead work that looks like it has always been there and lead work that announces itself from the garden, which on a conservation-area cottage is the whole point.

What the survey grades on a hand-made roof

Because the covering is doing so much of the work, the survey on an Earls Colne roof is as much about the tiles as about the structure. We look at the state of the batch: how many are frost-damaged or delaminating and will not survive another twenty years, how consistent the sound ones are in length so the courses around the opening can be brought to a regular gauge, and whether there are enough salvageable spares or a matched reclaimed source will be needed. Under the tiles we check what is there, because many of these roofs pre-date underlay and were weathered by torching, the lime mortar buttered under the tiles, which crumbles with age and leaves the tiles either side of an opening less resistant to wind. Above the ceiling we check the structure, which on this stock is usually a traditional cut roof of decent-sized rafters and purlins, more forgiving of an opening than a Victorian terrace but still worth measuring rather than assuming. All of it goes into the fixed price, so the labour the tiles demand is priced in from the start rather than discovered halfway up the scaffold.

Getting a price in Earls Colne

Every job is surveyed on the roof and priced once in writing. The figure holds unless you change the specification. A 10-year workmanship guarantee, installed to current Building Regulations, by installers with 25 years fitting rooflights on exactly this sort of covering.

We work across this part of north Essex, including Halstead, Coggeshall and Sible Hedingham. The full list is on areas we cover.

Request a fixed quote for a rooflight in Earls Colne. A close photograph of the tiles from ground level tells us a lot before we come out.