Insulation in Stone

Insulated at build, never touched since. Where a house here was insulated when it was built and left alone since, the roof was finished with a single layer laid between the joists. It is usually dry and usually worth keeping. What it is not is deep enough.

We add a second layer of mineral wool, an eco roll running at right angles across the joists, between and over, which brings the depth up and takes the timber itself out of the heat path, and we deal with the perimeter properly instead of stopping a foot short of it the way the original layer almost always does.

Cavity walls from the eighties were often built partial fill, with a board fixed against the inner leaf and a clear gap left in front of it, which is a different animal from an empty cavity and changes what can sensibly be blown in later. It needs a borescope and a look at the top of the wall, not an assumption: what is in there, how much clear space is left, and whether the wall is dry. Where a full fill would bridge to the outer leaf on an exposed elevation we say no, and we would rather say it before you pay for it.

Rooms over garages. Where a house has a room built over the garage or above an open porch, that is usually the coldest room in it. The reason is under the carpet rather than over the ceiling: a heated floor sitting on top of an unheated space with nothing in it. We insulate between the floor joists, from the garage side where the ceiling allows and by lifting boards where it does not, and we close the cold bridge at the edge where that floor runs out over the wall below. It is a half day that changes a room people had given up on.

On the Pamphill side it is brick and flint under a heavy roof, solid walls with no cavity to fill, and eaves that come down low enough that depth runs out exactly where you want it. Vent trays hold the airway open and rigid board goes in at the perimeter where a roll will not fit. Any internal wall insulation on a wall like that has to be vapour open, a breathable board with a lime finish, or you move the damp rather than remove it. Where an attic has been converted into a room in roof it is rigid board again: PIR such as Celotex between the rafters with a clear air gap kept above, a multi-layer quilt such as TLX under a sloping ceiling with no depth to give, and the dormer cheeks done at the same time. Then the loft's own details: lagging on the pipe runs above the new layer and a raised deck where boarding and storage go back.

The loft sets most of it. An estate cottage with a hatch on a half landing, a modern house with a loft ladder already in place, and a room over a garage insulated from underneath are three different days of work.

The old layer. Flattened wool that is dirty or has been wet goes into bags and away. Wool that is clean and dry is left where it is and a cross layer goes over the joists.

Walls. A cavity from the eighties may be empty, partly filled or full, and one look with a borescope answers that. A cottage with solid walls can only be lined inside or insulated outside.

Flats. In a block the loft and the outside walls are the freeholder's, so work there goes through the agent, and a bigger job may need the leaseholders consulted under section 20 of the Landlord and Tenant Act 1985.

Air at the eaves. Stuffing insulation into the eaves stops the roof breathing and puts the damp into the rafters, so trays and vents are priced on their own.

The U-value to aim for comes from Approved Document L. Ask any other quote how deep the new layer will be, whether the old one is being taken out or covered, and how the eaves are being kept open.

We cover Stone and Pamphill, Wimborne Minster, Furzehill, Cowgrove and Shapwick on BH21. The trip from our Boscombe base to Stone is about nine miles, and Dorset Council is the planning and building control authority.

Bournemouth Roofing & Building Ltd is registered in England and Wales; the company number is 15471719. Thomas Hannen, whose business it is, goes up into the loft and prices the job. Checkatrade lists a 10 out of 10 for us from a verified customer. The survey visit is free, as is the written quote with every item listed. Before you book a visit in Stone, you can read our customers' Google reviews, word for word, on our reviews page.

Most repairs in Stone 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.