Rooflights and skylights for brick semis in South Kirkby and the converted rooms behind them

Telling it from ordinary condensation

A film of water on the inner face of the glass on a cold morning comes from the room air and wipes off. Fogging that sits between the panes stays whatever the weather, and a fresh clean of both faces makes no difference. That points to a failed seal, which a cloth cannot reach.

New glazing or a new rooflight

If the frame is sound and the kerb is square, a new glazed unit can go into the existing frame. A worn frame, single glazing or a tired upstand round the kerb points to a whole new rooflight instead. From the roof we examine both, and the quote that follows is for one named unit at one stated size.

Disturbance in the room below

A replacement in the same opening keeps the work on the roof and in the reveal. The ceiling edge round the old frame is cleaned back and the plaster is touched in where the new unit sits slightly differently. A floor sheet and a tidy finish leave the room as it was, apart from the clearer glass overhead.

What the new glass brings

A current sealed unit has two or three panes on a warm-edge spacer, with a low-emissivity coating. A new rooflight has to reach 2.2 W/m²K, and every drop in the figure keeps more heat in the room. On an older single-glazed unit the gain is larger.

Keeping the roof dry round the kerb

The kerb is the part of an old rooflight that can outlast its glass, and it is inspected for rot and for any softening of the covering before a new unit is fitted.

The new unit is sealed into the roof's covering, which may be felt, EPDM rubber or GRP fibreglass. Each of those takes its own upstand and weathering detail, so the first job on the roof is to see what is there. A size from the maker may be measured to the inner or the outer edge of the kerb, and the replacement is measured to suit.

Flat roof or pitched roof

On a flat garage roof the rooflight sits on a kerb built up from the deck, and the covering is carried up the kerb's sides. A pitched garage roof takes a roof window framed between two rafters, with the tiles lifted and relaid around it. We check which kind of roof is there before a unit is named.

Choosing the spot over the room

The middle of a long, narrow room is the obvious place, but the position also follows where the joists run and where the room is used. A desk or a bed marks where the light should fall, and a play area wants it spread across the floor. The kerb is set out on the roof once that is agreed.

The ceiling void

A converted garage may have been given a new ceiling, with insulation above it. The opening has to go through that ceiling as well as the roof, and a lined light well joins the two. The joists run one way across the room, so the opening is set between a pair of them and the structural work stays small.

Glass for a room that is lived in

A garage room is occupied for long stretches, so the comfort of the glass counts for more than it would in a store.

A room used every day needs glass that holds its warmth. Glass on a warm-edge spacer suits a room used daily, and where full sun reaches the roof a solar-control coating keeps summer heat in check. A roof window that opens adds fresh air to a room with few windows.

Making good inside the garage

A garage ceiling is often lower than a room ceiling, so the light well is kept shallow and its sides are angled to spread the daylight. The light well is lined, insulated round the frame and plastered, and the ceiling around it is finished ready for paint. Where the old garage ceiling is plasterboard, the cut edge is taped and filled. The floor is sheeted before cutting, so a new floor or carpet is not marked.

Permission for the roof

Wakefield Council can confirm the position for a converted building, and the conditions for a rooflight on a house are in the skylight planning rules.

What sits over the bathroom

What sits over the bathroom settles the choice. Under a pitched roof with a loft void, a sun tunnel fits, because the tube can thread between the rafters. With a flat roof directly above, a flat rooflight sits on a kerb. With another bedroom or a bathroom above, the roof cannot reach the room at all.

Planning the tube

A sun tunnel runs from a small dome at roof level, through a reflective tube, to a diffuser in the ceiling. A straight rigid run gives up less light than a flexible tube that has to bend, so the route from dome to ceiling is kept as direct as the loft allows. If cutting a rafter or joist cannot be avoided, that is structural work and we send the notification.

Privacy and the ceiling

The diffuser is a panel in the ceiling, so nobody can look in from the roof. It sits flush in the plaster, and the plaster round it is finished white.

Choosing the spot on the bathroom ceiling

A bathroom ceiling has a shower, a bath and a basin to plan around, so the diffuser goes where it lights the room without hanging over the wet area. The dome on the roof is then lined up with it, and the tube joins the two. A small bend is possible where a rafter or a water tank is in the way.

Where the dome goes

On a tiled roof the dome sits on a short upstand in a flashing shaped for the tile. It adds little to the roof line, and the tiles round it are relaid over the flashing.