Wall insulation in Bryanston
In a pair of houses the wall you share matters as much as the one facing the weather, and both change what should be fitted.
The site visit is free and so is the written itemised quote. Thomas Hannen prices every job himself.
Bryanston is built in matched pairs and short runs rather than one-off houses, and that decides two things about a wall. Anything done to the outside changes the look of the whole run, not just your half. And the wall you share with next door is a party wall, so once battens or fixings go into it there is a notice to think about.
The calls are usually a cold end wall on a semi, mould in a corner bedroom where two outside walls meet, or a house where somebody wants to know whether the cavity was ever filled and whether it is still doing anything.
We start by settling what the wall is, with a tape at the reveal and a borescope through one small hole where there is a cavity to look into. Then the parts get priced separately in a written itemised quote. The site visit and the quote are both free.
The work
Semis, shared walls and the cold end of the pair
Settling what the wall is. Wall thickness at a window reveal and the bond in the brickwork usually tell you whether you have a nine inch solid wall or a brick and block cavity. Where they do not, one hole in a mortar joint and a borescope does. That gives the cavity width, whether it is clear and dry, whether the wall ties are bridged, and whether a failed fill is already sitting in there.
Cavity fill. A clear, dry cavity is filled from outside through a drilled pattern with bonded bead or blown mineral wool and made good in matched mortar. It is a day on most houses here. We do not offer a guarantee scheme of our own; a cavity fill is normally installed under an independent one, so ask whoever drills the wall which scheme covers it and keep the paperwork with the deeds.
A fill that has slumped. Settled material leaves the head of the wall empty and a wet mass at the bottom, and that is worse than an empty cavity because it hands water to the inner leaf. Black mould inside after a wet, windy spell is the usual sign. Extraction comes out through the lowest course and the cavity is cleaned before a new fill goes in.
Internal wall insulation. Insulated plasterboard on a continuous adhesive bed, or PIR such as Celotex or Kingspan between battens or a stud, taped and skimmed to BS 8000-8, with a vapour control layer where the wall is solid. Coldest rooms first. It takes width off the room and the sockets, radiators, skirtings and window boards move with it.
External wall insulation. Boards fixed and rendered over a render carrier. EWI gives the better U value because it wraps the building and cures the cold bridge at every floor junction, but on one half of a matched pair it looks exactly like what it is, so it is a conversation with the neighbour and the planners before it is a specification.
The party wall between you. Cutting battens, a stud or heavy fixings into the wall you share brings the Party Wall etc. Act into it, and a party structure notice is the usual route. It is not a hurdle, it is a fortnight of notice. The other thing about a party wall is that it is a thermal bridge in its own right: it runs from the warm side to the cold outer leaf, and lining up to it and stopping is what leaves a damp stripe on the return.
Reveals, eaves and ventilation. Reveals take a thin board, or aerogel where there is no room. The threshold and floor junction are returned rather than stopped short, and joist ends keep air around them. Then trickle vents, a working extract fan and clear air bricks, because Approved Document F sets the ventilation a tighter house still needs and BS 5250 covers the interstitial moisture that sealing a wall can trap.
How it runs
From your call to a written price
Same team from first visit to last, one person to ring, and no sub-contracting your work out to somebody you have never met. The quote is itemised, not a figure on the back of a card: the survey and any borescope check, the system and its thickness, making good around windows and doors, ventilation works, and disposal on separate lines, so you can compare it properly against anyone else's.
Nothing is left open or unusable overnight. The site is swept at the end of each day rather than the end of the job, and what comes out leaves with us. If something turns up once we start that nobody could have seen, you get a photograph and a price before we carry on.
Dorset Council is the planning authority and building control. Lining a wall inside is not development, which the guidance on insulation confirms, while cladding or rendering the outside is covered by what the rules say about cladding a wall. The Blandford St Mary and Bryanston Conservation Area controls appearance here, so external wall insulation is an application rather than an assumption. The listed entries nearby are concentrated on the Bryanston School estate rather than in the housing, but where a house is listed even internal lining can need listed building consent. And regulation 23 brings a whole wall up to the Part L standard once more than half of it is renovated.
Cost
What decides the price of a wall insulation job
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 semi with a shared drive, an end house with a full gable to the weather and a detached house with clear access all round are three different jobs. 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.
If damp has appeared
Damp or mould after a wall was insulated
Ring rather than use the form. Damp patches or black mould appearing on an outside wall after cavity fill or internal lining usually means water is tracking across the cavity, or warm air is reaching a cold surface at a junction. We look before we take anything out, because the fix depends on which of those it is. We are about sixteen miles away, so a wall that has gone damp here is normally looked at within a couple of days. The phone is answered 24 hours for emergencies; scheduled work runs Monday to Friday, 8am to 6pm.
Worth knowing
The wall you share, and the one you do not
In a pair or a short run of houses the party wall is the quiet problem. It is not an outside wall, so nobody insulates it, but it is joined to the outer leaf at the front and back and it runs all the way up. Heat moves along it, and where a lining stops against it you get a cold strip on the return that collects condensation and, eventually, mould.
The fix is not to insulate the party wall, it is to run the insulation a short way onto it, so the temperature drop happens inside the insulation rather than on the face of your bedroom wall. That is a detail, it takes an hour, and it is the first thing left off a cheap quote. Cutting into the wall itself is where the party wall notice comes in, and it is easier to serve one than to explain afterwards.
The same logic applies outside. Insulating one half of a matched pair changes the plane of the wall, the reveals and the eaves line on one side only. Either the pair is done together or, more often here, the work goes on the inside.
Who you are dealing with
A local firm you can check
We cover Bryanston, Blandford St Mary, Durweston and the lanes along the Stour, broadly DT11, under Dorset Council. 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.
Questions
Bryanston questions we get asked
Do I need to tell my neighbour before insulating my half?
For work on the inside face of your own outside wall, no. For anything cut into the party wall between you, or for external insulation that would run up to the boundary, yes, and a notice is the tidy way to do it.
Why is the corner bedroom colder than the rest of the house?
Two outside walls meet there, so it loses heat in two directions and the junction between them is a cold bridge. It is usually the first room worth lining and the one that shows the biggest change.
How long does a cavity fill take on a house like ours?
A day on most semis and detached houses, plus the survey visit beforehand. Internal lining is slower and is measured in rooms rather than houses, because the making good and decoration follow it.
Can we put external insulation on just our half of the pair?
Technically yes, visually no, and in the conservation area it needs an application you would struggle to win. Either the pair goes together or the work goes inside.
Was our cavity filled when the house was built?
Rarely, if it went up before the eighties. Most fills around here were retrofitted later. The borescope answers it in a couple of minutes and tells you what condition the material is in.
Nearby, and next door
Wall insulation near Bryanston
Wall insulation nearby
Our other trades in Bryanston
Everything we do in Blandford Forum Wall insulation, all areas Every area we cover
Free quote
Get the shared wall looked at as well as the cold one
Thomas comes out, checks the cavity with a borescope and prices the lining, the junctions and the making good in writing. Both are free.