Askern skylights and rooflights for newer estate houses, converted garages and windowless bathrooms

Why the kit has to match the profile

A profiled tile rises and falls across its width, and the gap under each hollow is filled by a flashing kit moulded to that shape. A slate lies flat and takes a thinner kit. A kit meant for the wrong covering leaves openings down the sides of the frame, which is where water finds a way in. The kits are set out under flashings for slate and tile.

Working the tiles round the frame

Tiles are lifted from the area of the opening and stacked to one side, and the timber strips beneath are cut back to the frame. Whole tiles go back round the flashing, and any that has to be cut is trimmed to sit neatly against the edge. The spare tiles from the opening are kept, so the roof is never left short.

Under the tiles and indoors

The felt under the tiles is lapped onto the frame, so water that gets under a tile runs down onto the flashing instead of into the house. Indoors, the lining is formed from the frame to the ceiling and plastered, with insulation packed round it so the layer carries on unbroken.

The planning side

Applications for Askern go to Doncaster Council. A house can normally add a rooflight under permitted development, unless it is listed, divided into flats or covered by an Article 4 direction. The conditions are laid out in a guide to the planning and Building Regulations side of skylights.

Spare tiles and colour

The tiles lifted from the opening are the same age and colour as the rest of the roof, so they are the best match for any gap that needs filling. A new tile bought to fill it would stand out against weathered neighbours for years, and it is the kind of detail that shows from the pavement.

Roof edges and ridges

Near a ridge or a hip, tiles are bedded in mortar or held with clips, and the frame is kept clear of those lines. A window fitted a safe distance below the ridge sits on plain courses of tile, where the flashing can lap properly. That is another reason the position is picked from the loft as well as from the room.

Matching what is already there

On a street of identical roofs, a new unit looks best when it is the same dark tone as the tiles and sits in line with the windows below. A kit in the right colour helps the flashing blend into the covering. The roof then reads as a single surface from the pavement.

Flat or pitched

A garage roof is either flat, covered in felt, rubber or fibreglass, or a shallow pitch of tiles. Flat roofs carry a rooflight or a lantern on a kerb, and pitched ones carry a roof window between the trusses where the spacing allows. Our pages on rooflights for flat roofs and roof windows go through both.

Headroom in a low room

Garage ceilings are low, and a lantern in a low ceiling can look heavy from inside. Flat glass keeps the ceiling clean. Under a shallow pitch the lining of a roof window is short, which keeps the light well compact.

Light for the far end

The far end of a long converted garage is the part furthest from the side window, so that is where the unit goes. A single rooflight set towards the back can light the whole length, and a second can be added in a longer room. The position is marked from inside, with someone standing where the desk or sofa will be.

Insulation in a converted room

The roof of a former garage often has little insulation, so the conversion is the moment to add some. A new rooflight with modern glazing replaces a cold spot in the ceiling, and the roof round it is insulated to suit. Under Part L a rooflight has to reach 2.2 W/m²K.

Planning for a garage

An integral garage and a separate one may fall under different planning rules for the roof, so Doncaster Council is asked which applies to yours.

What happens on the roof itself

On the day, the old covering is cut back, the kerb or frame is set and weathered, and the ceiling lining is finished within the room. We notify Building Control.

How the light travels

The dome collects daylight on the roof, the tube carries it down through the loft, and the diffuser at ceiling level spreads it into the room. The dome sits on a flashing cut for the tile. On a long run, the rigid kind of tube delivers more light, and every bend loses some, so a straight line is the aim.

Between the roof timbers

Modern roofs are often framed with closely spaced trusses, and the tube has to find a way between them. We measure from the loft hatch to see where the timbers run and where the bathroom sits under the roof. A timber that must be cut makes the job structural, with a trimmer fitted and the work notified. The order of work is laid out in the steps in fitting a sun tunnel.

Light and not air

A sun tunnel brings daylight only, and the fan stays where it is. The tube is sealed at both ends against steam rising from below and draughts coming from above.

A landing the same way

The landing of an estate house suffers in the same way. A tube set over the landing lights it, and the stair window at the end of the flight stops being the only light. Where the slope is long enough, a small roof window does the same work and opens for fresh air.

Where a tube can and cannot go

A tube needs a roof directly above the room. An internal bathroom on the upper floor of a two-storey house sits under the loft, so it qualifies. One on the ground floor has a bedroom above it and the tube must cross that room, which is rarely sensible. A landing on the upper floor, though, is often a good candidate.

Choosing the diffuser

Diffusers come in round and square shapes with a frosted or clear finish, and the choice follows the ceiling. A small bathroom takes a round one comfortably, while a landing with panelled ceiling lines may suit a square one.