Wall insulation in Christchurch

Settling what the wall is. Age is a hint, not an answer. A nine inch solid wall and an early brick and block cavity look identical once somebody has rendered them, so the wall gets drilled and scoped: is there a gap, how wide, is it clear, is it dry, is anything already in it. That is the fork in the road and it takes minutes.

Cavity wall insulation. Where a Christchurch cavity is clear, dry and wide enough, it is filled from outside through drilled holes made good in matching mortar. Bonded polystyrene bead flows into the corners and holds position, which is what an elevation facing the water wants. Blown mineral wool is the older answer and still right on a sheltered wall. A wet or narrow cavity gets left alone, and we will say so.

Internal wall insulation. On a solid Christchurch wall IWI is the practical route: insulated plasterboard bonded on, or battens and studs with mineral wool or PIR between, then boarded and skimmed. Celotex and Kingspan give more per millimetre; aerogel board earns its keep in a small room. The heat loss on a lined room is at the edges, so reveals, threshold, floor junction and joist ends are wrapped rather than butted up to.

External wall insulation. EWI means board on the outside face, a render carrier and a thin coat finish. On a Christchurch house it kills the thermal bridge at eaves and corners and keeps your rooms the size they are. It also changes the face of the building, so in the middle of town it is a planning question first and a technical one second.

Fill that has stopped working. Material settles in Christchurch walls, and a slumped cavity leaves a cold band at the head of the wall. A wet cavity is worse: driven rain crosses on the fill instead of running down the back of the outer leaf, and penetrating damp turns up inside, often as black mould in a corner. The borescope reads both, and extraction comes before any refill.

Ventilation and moisture. Insulating a wall shifts the dew point and removes the draughts that were drying the house out, so trickle vents, a working extract fan and any air brick that has been blocked up belong in the same quote. A taped, continuous vapour control layer keeps interstitial condensation out of the build up, and on a pre-1919 wall breathable materials beat a sealed one. The EPC moves; the payback you feel is the airtightness.

Wall insulation in Christchurch is priced on the kind of wall and on the detail at every opening and junction, far more than on its area.

Cavity or solid. An empty, dry cavity in an eighties house can be filled in a single visit. Solid brick has no cavity to fill; it gets insulated plasterboard on the inside or a system outside, both bigger jobs at a different price.

Driven rain. On a wall facing south-west towards the sea, rain can track across a fill. BS 8104 is how that exposure is assessed, and an exposed wall may need its pointing or render put right first, or a different approach altogether.

Getting to it. A rendered cottage on a narrow street, a post-war semi with a side path and a house on an open plot are different before a hole is drilled. Bungalows are drilled from a tower; a tall gable gets scaffold, under the rules for work at height. Lining is done from indoors, room by room.

Edges and openings. Window and door reveals, where the floor meets the wall, the eaves line and any party wall are where warmth escapes and damp appears when the detail is skimped. It takes time, and a low quote usually leaves it out.

Ask the other firm whether they have looked inside the wall with a borescope, what they are fitting and how thick, and who puts the plaster and decoration back.

We cover the town centre, Purewell, Stanpit and Somerford, plus the surrounding BH23 addresses, 2.7 miles from our base in Boscombe. Walls in all of them come under Bournemouth, Christchurch and Poole Council. Bournemouth Roofing & Building Ltd is registered in England and Wales, company number 15471719. Before you book a visit in Christchurch, you can read our customers' Google reviews, word for word, on our reviews page.

The firm is run by its owner, Thomas Hannen, who checks your wall with the borescope and prices the work himself. On Checkatrade a verified customer has left us 10 out of 10. There is no charge for his visit, or for the itemised quote he writes.

Most repairs in Christchurch 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.