Rooflight and skylight installation in Parsons Heath

Shallow pitches

Post-war roofs here are often shallower than the older stock in town, and pitch decides which product is possible. Below about fifteen degrees a roof window is the wrong product, and a rooflight on a kerb is the right one because the kerb supplies the fall the roof does not have.

It takes five minutes to check at survey and it saves specifying something that cannot be fitted.

Replacements

A great many rooflights around here date from the 1990s, which puts them at the end of a sealed unit’s life. Misting is the usual symptom, and it is not an emergency: nothing is getting into the building, the unit has simply lost its cavity and most of its insulating value.

Where several units were fitted at the same time they will fail at roughly the same time, and doing them in one visit shares the access cost across all of them. That is the main argument for replacing them together rather than one a year. It is covered on the replacement page.

Skylight and rooflight work we cover in Parsons Heath

Roof lanterns, flat roof rooflights, roof windows, VELUX replacements, conservation units and sun tunnels, all surveyed before they are quoted. We also work in Greenstead, Highwoods, Wivenhoe.

Post war estate roofs

Parsons Heath sits on the north eastern side of Colchester and the housing is predominantly post war, built from the 1950s onward, with concrete interlocking tiles, pitches around 30 to 35 degrees, and a mixture of traditional cut roofs on the earlier blocks and trussed rafters on the later ones.

That mixture is the first thing to establish, because it decides how wide a rooflight can be and therefore what the job costs.

Opening, and how you will actually work it

A rooflight that is awkward to open does not get opened, and a room that is never ventilated gets condensation. So the opening method is a comfort decision rather than a luxury one, and it is worth thinking about before the order rather than after.

Manual with a pole. Cheapest and perfectly good up to about two and a half metres. Above that it becomes a chore, the pole lives in a cupboard, and the window stays shut all year.

Mains electric. A wall switch, a handheld remote and a rain sensor that closes the window when it starts raining. The premium on the unit is modest. The wiring is where the cost sits: during a conversion at first fix, a cable to the rooflight position is twenty minutes clipped to a joist. Into a finished room it means lifting flooring above or ceiling below, chasing a wall for the switch drop, and redecorating.

The single most common regret in this trade is fitting manual to save the premium and wanting a motor two years later. If any work is being done, run a capped cable to the position even if you fit a manual unit. It costs almost nothing and it turns a disruptive future job into a cheap one. Photograph where it is before the ceiling closes.

Solar. Carries its own panel and battery, needs no connection at all, and fits in a couple of hours with no disruption below. That makes it the usual answer for retrofit into a finished room, which describes most Parsons Heath jobs. It works better than people expect: the panel needs daylight rather than direct sun, so it functions on a north slope through an East Anglian winter. It opens more slowly, thirty to sixty seconds against fifteen to thirty, which nobody notices in use. The battery is a consumable good for several years and it is replaceable.

Coverings, and getting the flashing kit right

Almost every roof in Parsons Heath is concrete interlocking tile, and that has one consequence worth stating plainly: it needs a deep profile flashing kit, not the flat kit used on slate.

An interlocking tile has a raised profile with a channel running down it. A flat flashing kit, designed to sit against a smooth slate, leaves open voids under those channels where it crosses the tile. Water gets under them within a season, and because it enters below the flashing it appears inside as a leak that seems to come from nowhere.

This is the most common installation fault we find on other people’s work in this part of Colchester, and it is the classic place a cheap quotation saves money, because the kit is a separate order line and nobody sees which one was used once the job is finished.

When comparing quotations, ask which kit is specified for your covering by name and part number. A quotation that cannot answer that has not been written from a survey.

Tiles that break

Concrete tiles from the 1950s and 1960s are generally robust and lift cleanly, which makes the work quicker than on a fragile clay roof. Some will be at the end of their life and a proportion will break on removal regardless of care.

Matching a sixty year old concrete tile is easier than matching handmade clay but it is not always possible, because profiles and colours were discontinued long ago and the survivors have weathered. Where an exact match cannot be found, the answer is to take sound tiles from a rear or hidden slope and put the replacements there, so the visible elevation stays consistent. We allow for a small number of replacements on any roof of that age rather than treating it as a surprise on the day.

Blinds and shading

Worth deciding before the unit is ordered, because it affects which product to choose.

Mass market roof windows have a full accessory range of blinds that clip to the frame without tools: blackout, pleated, venetian and external awnings. They fit exactly and cost far less than a made to measure blind fitted to a reveal.

The distinction that matters is internal against external. An internal blackout blind controls light and privacy and does relatively little about heat, because the sun has already passed through the glass into the room before the blind stops it. An external awning intercepts heat outside the glass and is dramatically more effective in summer, which on a south or west facing unit is the difference between a usable room and an unusable one.

Where a blackout blind is wanted over a bedroom, order it with the window. Retrofitting is possible and it is fiddlier and more expensive.

On a solar powered opening unit, a solar blind runs from its own panel too, which avoids a second wiring question.