Skylights and rooflights for the brick houses and bungalows of Ferrybridge

The loft of a terrace is usually just joists, a tank and a few stored boxes. The stairs and landing stay as they are, and the job is kept to the roof, the roof space and one ceiling.

Finding a straight run

The best tube is a short, straight one. The ridge of a terrace runs along the middle of the house, so the ceiling of the dining room is seldom directly below the slope. We look for the stretch of roof nearest the room and judge whether a gentle angle or a straight drop will serve. Rigid tubing keeps more of the light than flexible tubing, so any flexible section is saved for the last short stretch past a joist.

Between the joists

A water tank, a run of pipes or a few boxes can sit in the way of a tube, so the route is chosen to clear them. The spacing of the rafters can be read from the loft hatch, and it shows how much room the dome and tube have.

Dome and tube are slim enough to pass between the rafters, which leaves the roof structure alone. If the route does force a rafter or joist to be cut, it becomes structural work and we notify it.

The roof covering

A brick terrace of this kind will carry slate or concrete tile, and the flashing is chosen to match. The covering is lifted by hand around the dome and relaid over the flashing, so rain leaves the slope as it does elsewhere.

Daylight at the table

A dining room is used at set times, usually when people sit down together, and a ceiling that is bright by day makes a difference to meals as well as homework.

The ceiling light stays for the evening. By day the diffuser spreads daylight over the table and the sideboard.

Making good the ceiling

The table and floor are sheeted before a round opening is cut in the ceiling. The edge of the diffuser is taped, filled and painted, so the dining room is ready for the family's next meal.

A lantern is a different question

A roof lantern stands far taller than 150mm, which usually puts it outside Class C. The extension's own permission may cover it, and where it does not, the council is asked. If the extension is still on the drawing board, putting the lantern on the plans settles the question early.

Flat roofs and what they are made of

Felt, rubber (EPDM) and fibreglass (GRP) coverings are each turned up an upstand in their own way. A rooflight sits on a raised kerb built into the deck, with the covering turned up it and over the top edge. We note which covering you have and how old it is, because a cracked strip around the opening makes a poor base for new glass.

Where to put it

A deep extension is lit from one end, so the position is chosen on the plan before the roof is touched. We mark the ceiling at the point where people stand, then check that the joists below and the deck above will take an opening there.

Over the worktop or the table is where people spend time, and that is where the light does most. A rooflight over the end furthest from the garden doors lights the back of the room, where the house wall blocks everything else.

Opening or fixed

A fixed unit lets light in and nothing more. An opening one also lets steam and warm air out, and an electric model is operated by a switch or a remote handset, handy for a unit out of reach. Rain sensors are fitted to a number of these models and close the sash when wet weather starts.

What a wider opening involves

The rafters either side of the old opening may need cutting back, with new timber framed round the bigger hole to carry the load they carried. The width is set to suit your rafter spacing, so a unit slightly wider than the old one can fit more easily than one far wider. The new size appears in the written quote.

Matching the covering

A bigger frame means lifting more slate or tile around it. Slate is thin and can crack when lifted, and any that does is swapped for the closest match. Concrete tile is thicker and more forgiving. In both cases the flashing kit is the one made for your covering, so rain sheds as it should.

Heat and the Part L figures

For a replacement roof window, Part L sets 1.4 W/m²K or Window Energy Rating band B, and for a rooflight it sets 2.2 W/m²K. An old single-glazed unit comes nowhere near either, so the new one loses a good deal less heat through the same room. Extra panes, warm-edge spacers and a coated glass surface are the usual way of reaching the figures.

Whether it is time

Water forming on the inside face of a single-glazed unit is a separate matter and does not point to a failed seal.

Fogging between two panes means the seal around the edge has failed, leaving moisture sealed inside the unit. New sealed glass may do if the frame is sound, and a whole new rooflight is the answer where it is not. That is the moment to ask whether a larger one makes sense.

Inside the room

A larger opening needs a larger reveal. The lining is replastered back to the ceiling and finished as quoted, with the floor and furniture sheeted before the work starts.

Getting to the roof

A two-storey house needs a roof ladder or scaffold to reach the slope safely. A bungalow or a single-storey extension is lower, so the working at height is shorter, but the same care goes into protecting the covering we step on and the gutters beside it.