Loft insulation in Three Legged Cross

A second layer goes on. A newer house in Three Legged Cross came with one layer laid between the joists, and it is usually still where the builder put it. That is a better starting point than an old retrofit, but the timber is left uncovered and every joist runs heat through the ceiling.

What is already in a Three Legged Cross loft stays, the settled patches are filled, and a new unbacked roll is cross laid over the top at right angles to it. Two layers get you to about 270mm, which is what a current U value asks for, and no timber shows.

What has to come out. Not much, in a newer Three Legged Cross house, but it is worth checking rather than assuming. Wool that is wet, compressed flat under boarding, patchy where somebody has crawled through it or contaminated with droppings is bagged in the loft and taken away rather than covered over. Older properties in the village can also have loose fill that has migrated into the eaves and closed them off.

Trusses, and moving about. These Three Legged Cross roofs are trussed, so there is bracing to work around and the ceiling ties are shallow. Nothing gets cut, notched or unbolted to make the job easier. We work off boards laid across the joists, feed the material through the truss webs, and do the far corners before the near ones, since the last corner reached is the one that ends up short of depth.

The eaves. The insulation runs out over the wall plate and stops there, with a vent tray in each rafter bay holding the air gap open so cross ventilation still crosses the loft. Modern roofs are laid on a breathable membrane, which is more forgiving than old bitumen felt, but they are also tighter than an old unfelted roof and they rely on the eaves. Push material into that edge and you get condensation on the underside of the covering and mould along the timbers within a winter.

Services, storage and roof rooms. Recessed lights are common in houses of this age and every one gets a fire rated cover, with cable and wiring lifted and clipped above the new layer rather than buried in it. Where there is a tank, it and its pipework are lagged and a lid fitted. Storage goes onto loft legs as a raised floor so the full depth stays uncompressed, with a platform at the top of the loft ladder, and the hatch gets an insulated board and a draught seal. A room in the roof, a dormer or a sloping ceiling is rafter level work instead: rigid board such as Celotex between the rafters, the air gap kept open above, PIR beneath and the vapour control taped through.

We do not charge a rate per square metre. The floor area is the simple part. The edges and what is already there take the time.

Getting in. A hall hatch in a bungalow, with room underneath for a step ladder, is straightforward. A tiny hatch above the stairs in an eighties house, or a loft floor that is boarded and has to be lifted and relaid, eats time before any roll is opened.

What is up there. Old quilt that is dirty or damp gets bagged and carried out. Stored boxes have to come down and go back. Open joists with nothing in the way go quickly, and a trussed roof full of diagonal bracing does not.

The eaves. The new mineral wool must reach the wall plate without choking the air gap at the eaves, or the loft turns damp. Filling corners, working round the hatch and any downlighters, and lagging the tank and pipes left in the cold is where most of the labour goes.

Keeping storage. If you still want to store things up there, raised boarding above the new depth adds time and material.

Worth asking any other firm: how deep will it be once finished, will the old quilt be removed, and how will the eaves be kept open?

Many homes in Three Legged Cross went up in the twenty five years or so before the financial crash, which is recent enough that most owners assume the loft was done properly and never look.

The material up there is usually still neat, still dry and still exactly as deep as the day it was laid, and that is the problem. What counted as enough when the house was built is well short of what is expected now, and it was laid between the joists rather than over them, so the timber has been leaking heat through the ceiling ever since.

It also means the work is simple and quick here, which is worth knowing before you put it off. There is rarely anything to clear out, the roof space is dry, and the second layer goes straight over what is there. The parts that do need attention are the eaves, because a builder laying to the standard of the day often stopped at the wall plate rather than reaching over it, and the boarding, because a lot of these lofts were boarded for storage straight onto the ties. Lift that onto legs and the depth underneath stops being wasted.

Lofts in Three Legged Cross, Verwood, West Moors, Woodlands, Alderholt and the nearby BH21 addresses are a short drive for us, roughly nine miles from Boscombe, and Dorset Council covers planning and building control. The firm is Bournemouth Roofing & Building Ltd, registered in England and Wales, company number 15471719. Before you book a visit in Three Legged Cross, you can read our customers' Google reviews, word for word, on our reviews page.

It belongs to Thomas Hannen, who goes up the ladder and prices your loft himself. On Checkatrade, one verified customer gave a 10 out of 10. There is no fee for the visit, and the written, itemised quote is free.

Most repairs in Three Legged Cross need no application at all. What decides whether a change to the outside of your house does is who the council is, whether a conservation area or a listing applies, and whether the place sits in a protected landscape.