Loft insulation in Spetisbury

Air first, because the order matters. Insulation is carried across the ceiling until it sits over the wall plate and it stops there, with a vent tray at each rafter holding an air gap open above it.

That gap is the route: cross ventilation moves from one eaves, along under the felt and out the other side, taking vapour with it. Where a roof has boxed soffits that cannot be opened, a ridge vent or a run of tile vents does the same work from higher up, and a modern breathable membrane changes the detailing rather than removing the need. Approved Document F is the standard behind it. Get this right and the loft stays dry however cold it gets. Get it wrong and the dew point sits inside the material, interstitial condensation forms where nobody can see it, and black mould appears on the rafters within a winter.

The hatch in a Spetisbury house belongs to the same argument. A bare trapdoor in an untreated lining is the main way warm wet air leaves the house and enters the roof, so it takes a rigid board on its back and a compression seal round the lining before any depth is discussed. Extract fans in the bathroom and kitchen are worth a look at the same time, because a fan discharging into the loft instead of out through the wall will defeat everything else in this list.

Only then the depth. Whatever is in the Spetisbury loft now gets read first: it will have settled, gone patchy, been compressed under storage and stopped short at one edge, and if it is damp, dusty or contaminated with droppings it is bagged in place and carried out. Sound wool stays as the base layer, teased apart and levelled between the joists. Over it goes the second layer, cross laid across the joists at right angles so the timber is buried and stops carrying heat down into the plaster. About 270mm finished is the depth a renovated ceiling is expected to reach under Part L in Approved Document L. Mineral wool roll on the open floor, rockwool batts where the bays vary, glass wool, loose fill in the corners, sheep wool if you prefer it, PIR rigid board and multi-foil where the headroom has gone.

Then the fittings, quickly, because they are easy to leave out. Fire rated covers over recessed lights and downlighters. Cable and wiring lifted onto the new layer rather than buried under it. Lagging on the cold water tank and its pipework, which are now sitting in genuinely cold air. Loft legs and a raised floor where you want storage, so the boarding and the platform clear full depth, with the loft ladder set to suit. And where a roof has already been converted into a room in roof, the whole approach changes to a warm roof at rafter level, with a taped vapour control layer behind the plasterboard and the sloping ceiling and dormer cheeks treated as carefully as the flat part.

No Spetisbury loft is priced per square metre. The edges and the access take the time, not the open floor. The hatch. A hatch on a landing with a fitted ladder is simple. A small hatch over the stairs, or one in a bedroom cupboard, slows everything down.

What is stored up there. Boxes to move, boarding to lift and relay, and a water tank to work around all add time.

The old layer. Clean, dry insulation can stay. Wet, flattened or dirty material has to be bagged and taken away.

Eaves and ventilation. Felt roofs of this age rely on air coming in at the eaves. Keeping that path open with trays is fiddly work on your knees.

Pipes, tanks and lights. Anything that ends up in the cold above the insulation has to be lagged, and downlighters need covers. Approved Document L sets what the job is expected to reach.

A loft that is being used. If you want to keep storing things up there, the boards have to be raised on loft legs above the new depth, which is more material and more time than rolling out a layer and walking away.

Ask anyone else quoting what depth goes in, whether the old material comes out, and whether the hatch, tank and pipes are included.

Spetisbury has two clearly different sorts of roof along this stretch, and they want different things. The older houses are pre-war cottages with cut roofs, purlins through the space, hand cut joists at spacings that wander, and often no underlay at all. The larger share went up between the war and the early eighties, mostly semis and terraces with trussed roofs, a sealed underlay and one thin quilt rolled out when they were built.

On the older roof the ventilation is largely a gift and the difficulty is fitting material to a space where no two bays match, which means batts and cutting rather than rolling. On the later roof it is the reverse: the floor is regular and easy to cover, but the roof is sealed above and the original layer has usually been shoved into the eaves, so the air path is the thing that needs rescuing. Ask anybody quoting which of the two you have and what they intend to do about it. If the answer is the same for both, they have not been up there.

Lofts we insulate include ones in Spetisbury, Charlton Marshall, Blandford St Mary and Blandford Forum, with Dorset Council as building control. Spetisbury is 14.2 miles from our Boscombe base. Bournemouth Roofing & Building Ltd is registered in England and Wales, company number 15471719. Before you book a visit in Spetisbury, you can read our customers' Google reviews, word for word, on our reviews page.

The person who goes up into your loft to price the job is Thomas Hannen, who owns the company. We hold a 10 out of 10 on Checkatrade, left by a verified customer. The loft survey is free, and so is the written quote itemising each part.

Most repairs in Spetisbury 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.