Insulation in Corfe Mullen

Topping up a loft that was insulated when the house was built. Sixty-two per cent of the housing here went up between 1945 and 1982, with a third of the whole village dating from the 1970s and early 1980s, and a loft of that age typically got between an inch and three inches of wool. Mineral wool, ordinary eco roll, goes down in two layers, the first between the joists and the second straight across them so the joists stop acting as a cold bridge through the whole ceiling. Full depth is around 250 to 270mm, which brings a roof close to the 0.16 u-value expected of a renovated roof today. The old compressed layer stays put and counts towards the total.

Bungalows, and boarded lofts. A third of the dwellings here are bungalows, so the entire floor plan sits under the roof and the ceiling is by a distance the biggest heat loss surface in the building. It also means more square metres to cover, and we measure the actual footprint on the visit rather than working it out from the outside of the building. Boarding laid flat on the joists caps the insulation at joist depth and quietly wastes the top up you have just paid for, so loft legs lift it clear, full depth runs underneath and you keep every inch of storage. Where the boarding is old chipboard that has sagged we will say so rather than lift and relay something ready to fail.

Plenty of houses here have a room in the roof, often with a dormer on the back built as a warm roof, and there the insulation goes between and under the rafters instead of across a floor: rigid board, PIR and foil faced, cut tight into each bay and taped, or a multi-layer foil quilt such as TLX where headroom is tight. The cold triangles behind the knee walls and above the flat section of ceiling are where the heat actually goes, and they are the parts most quotes forget.

Houses of this era were built with a cavity and around here it has usually been filled at some point by somebody, so whether the fill is still even, whether it has slumped and left a cold gap at the top, and whether it has bridged and gone damp are all borescope questions. Vent trays go in at the eaves so wool is not blocking the air path, because a warm ceiling under a cold roof needs that roof to breathe or you swap a heat problem for a damp one, and Approved Document F covers that side. Then lagging on the tank and on the pipework now sitting above the warm layer, and fire rated covers over the downlighters before anything is laid over them.

A bungalow with the whole footprint under one loft, a chalet with rooms already in the roof and knee walls to open up, and a semi with a boarded loft full of storage are three different jobs for the same address on paper. Old material to bag and take away, storage to move and put back, and eaves that must stay clear all come first, and Approved Document L sets what the work has to reach. Comparing quotes, ask what depth is being laid, whether the old material is removed or covered, and whether the hatch and pipework are included.

We cover Corfe Mullen and the roads around it, Lambs Green, Higher Merley, Broadstone, Upton and out to Wimborne, and the BH21 addresses across them. Bournemouth Roofing & Building Ltd, registered in England and Wales, company number 15471719, which you can look up in a minute. Thomas Hannen's business, and he is the one who comes out to price the job, not a salesman. A verified customer's 10 out of 10 on Checkatrade. The visit and the written quote are both free.