Wall insulation in Blandford Forum
Solid brick in the middle of town and cavity walls around the edge, so the first job is finding out which of the two you actually own.
The site visit is free and so is the written itemised quote. Thomas Hannen prices every job himself.
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Wall insulation in Blandford Forum depends on which half of town you are in, because the answer turns on cavity or solid. Blandford is two towns as far as a wall is concerned. The Georgian brick centre has solid walls with nothing inside them to fill, so the routes are lining the inside or insulating the outside, and outside is a planning matter here. The estates around the edge are brick and block with a cavity, and there the first job is finding out what is already in it.
Blandford Forum houses like these tend to have cold front rooms, mould on outside walls or old fill gone damp. A front room in one of the town houses that never gets warm however long the heating runs. Black mould in the corner of a bedroom on an outside wall. Or a house filled years ago under a scheme nobody kept the paperwork for, where damp now shows inside after driving rain.
We look at the wall itself before naming a system: thickness at a reveal, the bond in the brickwork, and a borescope through one small hole where there is a cavity. The site visit is free and so is the written itemised quote, and where the honest answer is that your wall is better left alone, that is what it will say. Insulation in Blandford Forum covers the loft and floors.
The work
Solid brick in the middle, cavities on the edge
Finding out which wall you have. A nine inch solid brick wall and a brick and block cavity wall look the same from the pavement. The tells are the thickness at a window reveal and the bond, and where those are not conclusive we drill one hole in a mortar joint and put a borescope through. That gives the cavity width, whether it is clear and dry, and whether anything has been injected already.
Cavity fill, where the cavity earns it. A clear, dry Blandford Forum cavity of decent width is filled from outside through a pattern of drilled holes, with bonded bead or blown mineral wool, and the holes made good in matched mortar. We do not offer a guarantee scheme of our own. Cavity wall insulation put in by a registered installer normally carries a CIGA certificate, so ask whoever drills your wall for it.
A fill that has failed. Old material settles in Blandford Forum walls too. A slumped fill leaves the top of the wall empty and a packed, damp mass at the bottom, which is worse than an empty cavity because it carries water to the inner leaf. The symptom is black mould inside after a wet, windy spell. Extraction comes out through the lowest course before anything new goes in.
Internal wall insulation. On a solid wall this is the practical route and in the centre of Blandford Forum usually the only one. 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. Coldest rooms first. It takes floor width, so reveals, skirtings, sockets and radiators move with it.
External wall insulation. Boards fixed and rendered over a render carrier. It is the best U value you will get on a solid Blandford Forum wall, because it wraps the building, leaves your rooms alone and cures the cold bridge at every floor junction at once. It also changes the look of the house, which is why here it is a planning question before a heat loss one.
The junctions, which are the actual job. Reveals, the threshold, the floor junction, the eaves and the party wall are where a lining either works or leaves a thermal bridge worse than the one it cured. Reveals take a thin board, or aerogel where there is no room. Joist ends in a solid wall need air kept round them, or they rot quietly.
Moisture and air. Insulating a Blandford Forum wall moves the dew point and cuts the air changes, so vapour control and ventilation belong in the same quote: trickle vents, a working extract fan in the kitchen and bathroom, air bricks left clear. BS 5250 covers moisture and Approved Document F the ventilation. Seal the draughts first; the payback is immediate.
How it runs
Insulating walls in Blandford, solid or cavity
The first job is finding out what your walls are. Thomas drills one small hole and looks through it with a borescope, which shows if there is a cavity at all, if it is clear, and if it was filled years ago. Only then does he write the quote: survey, system and thickness, making good at windows and doors, ventilation and waste, each on its own line. Which firm installs any fill is written on the quote.
An internal lining goes in one room at a time, with furniture moved, floors covered and the room back in use each night. Outside work needs a scaffold, which on a terrace fronting the pavement means a licence and a clear footway. Offcuts and old plaster leave with us. Damp in a solid wall or a failed lintel found along the way is photographed and priced before we go on.
Dorset Council is the planning authority. Lining a wall inside is not development, which is why the Planning Portal treats it differently from cladding. External insulation alters the outside, so on a listed building or in a conservation area it needs checking with the council first. On the town's 209 listed entries, listed building consent can be needed even for an internal lining. And regulation 23 means renovating more than half of a wall brings the whole of it up to Approved Document L.
Cost
What decides the cost of wall insulation
What happens at each window, door and floor junction matters more than how much wall there is. Which wall. Much of the town's housing is post-war with cavity walls, where a clear dry cavity can be injected from outside in a single day. The Georgian houses in the centre are solid brick and have to be lined inside or clad outside, which is a different job at a different price.
Filled already? Many post-war cavities were filled years ago. A borescope shows whether it was done, and whether the fill has slumped or got wet.
Solid walls need to breathe. A lining on a solid wall must let moisture move through it. Foil-backed board on an old wall can hold condensation inside the brick.
Cold spots. Window reveals, the floor junction, the eaves and any party wall are where heat leaks out and mould appears when the detail is poor.
Access. A town house on the pavement needs a scaffold for any outside work. A bungalow comes off a tower, and the work at height rules set the platform.
Ask any other installer whether a borescope has been used, what system and thickness is proposed, what U-value it will reach, and who puts the plaster back afterwards.
If damp has appeared
Damp or mould after the walls were insulated
Damp patches or black mould on an outside wall after cavity fill or a new lining need looking at. Keep the room aired and take photos, particularly if the mould runs along a window reveal or the skirting. Phone us; the form is slower.
Wall insulation is booked Monday to Friday, 8am to 6pm. When you phone about damp and nobody picks up, a call back follows as soon as we can. We find out whether rain is bridging the cavity or warm indoor air is meeting a cold surface, since each needs a different fix, and we photograph what we find.
Worth knowing
Why the outside of a Georgian wall is not your decision
The centre of Blandford was rebuilt in brick after the fire, and the old streets read as one piece rather than as separate houses. That is why the conservation area exists, and why external wall insulation on a frontage here is not a realistic proposal. It pushes the wall forward, buries the reveals and breaks the line of the terrace. Planning Portal guidance on external walls explains where cladding needs permission, and in a conservation area assume it does.
So on a solid walled house in the middle of town the honest options are a lining inside, or nothing. Lining is worth doing on the rooms you live in, but only detailed properly: reveals returned, the floor junction dealt with, joist ends left able to breathe, and a build up that suits an old wall rather than sealing it. Done badly it puts a cold, damp surface behind a warm board, and the EPC improves while the room does not.
The estates built from the sixties onwards are a different proposition. Those walls have a cavity, sit outside the conservation area, and a fill or external insulation on a rear elevation is straightforward there.
Who you are dealing with
Who insulates your walls, and how to check
Blandford Forum is 16.8 miles from our base in Boscombe. Wall insulation takes us across the town, Blandford St Mary, Bryanston and the Stour villages in DT11, with Dorset Council deciding anything that needs planning or building control.
Bournemouth Roofing & Building Ltd, registered in England and Wales, company number 15471719, is the company you are dealing with. Its owner, Thomas Hannen, runs the borescope check on your walls and prices the work himself. A verified customer has marked us 10 out of 10 on Checkatrade. The visit is free, as is a written quote with every line itemised. Before you book a visit in Blandford Forum, you can read our customers' Google reviews, word for word, on our reviews page.
Planning at a glance
Do you need planning permission in Blandford Forum?
Most repairs in Blandford Forum 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.
| Question | In Blandford Forum |
|---|---|
| Who decides | Dorset Council is the planning authority for Blandford Forum. Dorset Council's heritage pages set out what it controls. |
| Conservation area | Yes: Blandford Forum and Approaches Conservation Area and Blandford St Mary and Bryanston Conservation Area. They cover parts of Blandford Forum, so check whether your street is inside one. |
| Listed buildings | Yes, there are listed buildings in and around Blandford Forum. If yours is one, work can need listed building consent. |
| Protected landscape | No National Park or National Landscape covers Blandford Forum. |
Questions
Questions about wall insulation in Blandford Forum
How can I tell whether my Blandford house has a cavity?
Measure the wall thickness at a window reveal and look at the brick bond. A solid nine inch wall shows headers laid across it; a cavity wall shows stretchers throughout. Where that is not clear we drill one hole and look with a borescope.
Can I put external insulation on a house in the conservation area?
On a frontage, realistically no: it changes the appearance of the building and the street, so it needs an application. A rear elevation on a later house is a different conversation.
Will lining the inside make my rooms noticeably smaller?
Yes, and you should know before you start. Sockets, radiators and skirtings move with it, which is why it is normally done to the coldest rooms rather than the whole house.
Damp appeared after our wall was filled. What causes that?
Usually the fill has slumped or bridged, so water crossing the outer leaf now has a path to the inner one. Sometimes the wall was too exposed to fill at all. We look before taking anything out.
Is a warmer wall going to give us more condensation?
It can, if nothing else changes. A tighter house needs somewhere for moisture to go, so trickle vents, working extract fans and clear air bricks are part of the work.
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Free quote
Find out what your wall is before you insulate it
Thomas comes out, checks the wall thickness and puts a borescope through where there is a cavity, then prices it in writing. The visit and the quote are free.