Wall insulation in Bournemouth

The check that comes before anything. A nine inch solid wall and a narrow early cavity of brick and block look the same from the pavement. The borescope answers it in minutes: is there a gap, how wide, is it clear, is it dry, and has somebody already filled it. Everything after that follows from what is down the hole.

Cavity wall insulation. A clear, dry cavity of decent width is filled from outside through a pattern of drilled holes that get made good in matching mortar. Bonded polystyrene bead is the usual choice on an exposed elevation because it flows and stays put; blown mineral wool still suits a sheltered wall. A wall that is wet, or narrower than fifty millimetres, is one we will tell you to leave alone.

Blocks and converted houses. Cavity fill treats a whole elevation, so on a block it is a building decision rather than a flat decision, and the managing agent has to be in it from the start. Converted houses are different again: the party wall between two flats is often the only thing that was never touched, and a top floor gable can be doing most of the heat loss on its own. We quote in a form an agent can put in front of leaseholders.

Internal wall insulation. IWI is what a leaseholder can usually get on with. Insulated plasterboard bonded to the wall, or a batten and stud build up with mineral wool or PIR between it, then boarded and skimmed. Celotex and Kingspan buy you more for the depth and an aerogel board suits a room that has none to give. Reveals, threshold, floor junction and joist ends are all detailed, because a thermal bridge left at an edge undoes a wall.

External wall insulation. EWI is board fixed to the outside face, a render carrier over it and a thin coat finish on top. It wraps the whole building at once and deals with cold bridging at the eaves and corners in a way that lining one room never can. Close to the sea the fixings and the beads want specifying for salt, and the reveals, sills and rainwater goods all move outwards with it.

When the wall has already been done. Old fill settles, and slumped material leaves a cold band along the head of the wall. A wet cavity is worse, because water crosses on the material and penetrating damp appears inside on the weather side, often with black mould behind the furniture. Both are read through the borescope, and extraction comes before anything new goes in.

Ventilation, which is half the job. Insulating a wall moves the dew point and takes away the draughts that were drying the flat out, so trickle vents, an extract fan that genuinely shifts air, and any air brick somebody bricked up all come into it. A taped, continuous vapour control layer keeps interstitial condensation out of the build up, and breathable materials are the safer bet on an older wall. An EPC will move on the back of the work, but the payback you notice is the airtightness and the even warmth.

No rate per square metre, because the wall area is the easy part; what happens at every window, door and floor junction is not.

Getting to it. A purpose built block with a shared gable, a large old house cut into flats, and an ordinary semi are three different jobs before a hole is drilled. Cavity fill is drilled from outside and a bungalow comes off a tower where a three storey gable wants a scaffold. Internal lining is worked room by room from inside, so it is your rooms rather than a platform that gets disrupted. The work at height rules still set the platform.

Which wall you actually have. A cavity that is clear and dry can be filled in a day. A solid wall cannot be filled at all, and has to be lined inside or insulated outside, which is a different job at a different price. A borescope through one drilled hole settles it, and no honest quote is written before that.

The junctions, not the field of the wall. Reveals at windows and doors, the floor junction, the eaves and any party wall are where heat escapes and where condensation shows up if the detailing is wrong. That work is slow, it is most of the labour, and it is the first thing a cheap quote leaves out.

Comparing quotes? Ask whether the wall has actually been checked with a borescope or just assumed, what system and what thickness is specified, how the reveals and floor junction are being detailed, whether ventilation is being addressed, and who makes good the plaster and decoration afterwards. Two quotes for the same job are usually two different jobs.

We cover Winton, Charminster, Moordown, Springbourne and the BH8 and BH9 streets either side of them, with Bournemouth, Christchurch and Poole Council for planning and building control. You are dealing with Bournemouth Roofing & Building, the trading name of 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.