Wall insulation in Furzehill

Before anything is bought at all. Read the wall. A 12mm hole, a borescope, five minutes. That look gives the clear cavity width, mortar snots perched on the ties, an old fill slumped down the gap, anything wet. Every line below hangs off that answer, which is why no honest specification arrives over the telephone.

Purchase one, if the camera finds a cavity. Fill it. A Furzehill cavity that is clear, dry and wide enough means drilled on a pattern, pumped, made good, done inside a day. Bonded polystyrene bead travels round the ties and stays where it lands. Blown mineral wool is older and behaves well in a clean, sheltered gap. Holes close with mortar mixed to match.

Purchase one on a solid wall: the coldest room, edges included. Internal wall insulation, IWI, is either insulated plasterboard bonded straight onto the masonry or a batten and stud frame packed out with mineral wool. PIR laminate, Celotex or Kingspan, reaches the target in the shallowest build up. Old solid brick gets breathable layers instead, wood fibre under a lime skim, so the masonry keeps drying inwards and the dew point never parks inside the brick.

Bought in the same fortnight, not later. Returns, every window and door reveal, the threshold, the floor junction. Skip them and the room is not done. Vapour control layers are taped and sealed edge to edge as BS 8000-8 asks, and sockets and radiator brackets come forward onto the new face rather than being boxed round.

Bought alongside, never afterwards. Ventilation. Warmer walls lift the airtightness of a Furzehill house, and the water already in the air wants another way out. Trickle vents that open. An extract fan shifting kitchen and bathroom air for real. Air bricks nobody has rendered across. Approved Document F sets the expectation, and draught sealing in the same visit turns a better u value into a room that feels different.

Purchase two, a winter or three later. The next room in your Furzehill house, priced off a room you have lived in rather than a brochure. By then you know what depth you can stand. A small bedroom takes a thinner high performance board with aerogel at the reveals. Heat loss is never spread evenly round a house, so the order is coldest first, not clockwise.

Jumping the queue: fill that has failed. Wool pumped into a Furzehill wall decades back settles, leaving a cold band under the eaves that reads inside as black mould along the top of a bedroom wall. A wet cavity, water crossing on a bridge, throws damp patches that follow the weather. Neither waits its turn. Both begin with extraction.

Last, and only sometimes. External wall insulation, EWI: boards, a render carrier and a render finish across a whole elevation. Not an inch of floor space goes, the masonry warms right through, and the joist ends and floor junction settle in one pass. It also changes the face of the building permanently. Where a re-render is due anyway, that is the moment to raise it.

Wall insulation is never priced by the square metre here. The plain stretch of wall is quick work; the edges around it are not.

The house in front of us. An older detached house in its own grounds, a seventies house on a close and a bungalow on a lane all start differently. Filling a cavity means drilling from outside, and on a two storey gable that needs a scaffold rather than a tower, as the work at height rules require. Lining a solid wall happens indoors, and you lose the use of each room while it is done.

Cavity or solid. Most Furzehill houses of the late sixties and seventies were built with a cavity, and if it is empty, clean and dry it fills quickly. The older cottages have solid walls with nothing to fill, so the choice is insulated plasterboard inside or a render system outside. We look through a drilled hole with a borescope before writing anything down.

Cold spots. Around window reveals, at the floor edge, under the eaves and where a party wall meets the outside wall, heat leaks and condensation forms if the detail is skimped. Getting those right takes longer than the rest of the wall put together.

Exposure. How much wind-driven rain a wall takes affects whether a cavity should be filled at all.

Put these to any other installer: did you look inside the cavity, what product and thickness are you using, how will you treat the reveals, and who puts the plaster and paint right afterwards?

Furzehill is about eight miles by road from Boscombe, and we insulate walls across Colehill, Holt and the Holt Road side of Wimborne, broadly BH21, under Dorset Council. The company you deal with is Bournemouth Roofing & Building Ltd, registered in England and Wales, number 15471719. Before you book a visit in Furzehill, you can read our customers' Google reviews, word for word, on our reviews page.

It is Thomas Hannen's firm, and he checks the walls with you and prices the job himself. There is a verified 10 out of 10 on Checkatrade from one of our customers. The visit and the written quote, broken down line by line, are both free.

Most repairs in Furzehill 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.