Sun tunnel fitting time: how long does the work take?

Time on site follows the sequence, and each stage has its own variables. Nothing is worked out from a photograph, because the stages that vary most are the ones a photograph cannot show: the roof outside and the loft above the ceiling.

This stage is the one that must be watertight, so it is not hurried. The covering is lifted round the chosen spot, the opening is formed between the rafters and the base is fixed. The flashing is laid into the slate or tile courses, so that water runs over it and sheds onto the covering below. On a flat roof the base can stand on the deck or on a low upstand, depending on the maker, and the covering is carried up to meet it.

Slate, plain tile and profiled tile roofs differ, and the flashing is picked to match. The roof pitch and the height of the ridge change how long this stage takes, and rain can hold it back, because an opened roof should not be left to the weather. Where the sun tunnel goes in place of an old skylight or rooflight, that unit comes out first and the opening is adapted to the new base, which is an extra step of its own.

With the dome in, the tube goes in from the roof end down to the ceiling spot. Insulation lying on the route is generally pushed back while the tube goes in and returned around it afterwards, following the maker's guidance. A straight rigid drop through an open loft is the simplest route. Every elbow, every obstacle and every joint to be sealed and supported adds steps.

A flexible duct is stretched to length and fixed along its curve, which takes care so it hangs without sagging. Where the loft is boarded, full of stored belongings or reached by a small hatch, the work slows, simply because getting kit and sections up and around takes longer. A clear path to the hatch is a real help. Your loft is the part of the house we have least chance of seeing before we visit, which is why the time cannot be quoted from the doorstep.

A circular hole is cut in the ceiling to meet the tube, and the diffuser is fitted flush. This is the stage where dust is made, and where the finish shows. A plain plastered ceiling takes a neat edge simply, while a textured, tiled or boarded ceiling takes more careful finishing. If you want the edge decorated, we agree that at the survey rather than leaving it open. The diffuser itself is the only part of the whole job that the room will show, so the neatness of this last stage matters more than its size suggests.

Nothing here is a promise or a prediction, only a list of the things that make a job longer, so you know what the survey is looking for.

Cutting a ceiling makes fine dust, and the room below is covered and the floor protected beforehand. The loft is dustier still, mostly from moving insulation, so it is wise to keep stored things clear of the hatch. Outside, there may be broken or spare slates and tiles and some debris on the ground near the ladder or tower, which is cleared when the work ends.

The room under the diffuser is usable again once the work is finished, and any decorating around the disc is the last thing done. Pets and children are best kept out of the room and off the landing below while the ceiling is cut, and the hatch area is kept clear for the ladder to the loft.

Before we leave, you are shown how the diffuser is wiped from inside, how the dome is reached for cleaning from outside, and what to watch for. Once the diffuser is in the ceiling, our 10-year workmanship guarantee starts on that tube. For the price side, read what the work costs, and for the rules about the dome, the planning and regulations answer. The product as a whole is on our sun tunnel overview page. A rooflight or skylight elsewhere on the roof is a separate job and gets its own look.