Wall insulation in Broadstone
The cavity in a late fifties or early sixties house is the awkward one, and only a borescope will tell you whether it can be filled.
The site visit is free and so is the written itemised quote. Thomas Hannen prices every job himself.
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Most Broadstone houses have a cavity wall, and a borescope shows whether it is wide, clean and dry enough to fill. A lot of them went up in the late fifties and early sixties, and the cavity of that period is the awkward one. Often narrow. Frequently carrying mortar on the ties. Whether it can be filled at all is a question a borescope answers, never a brochure.
Typical problems in Broadstone: a bungalow with one cold flank, a house whose walls were filled decades ago where a bedroom corner has started going black, and somebody told their cavity is too narrow who wants to know whether that is actually true.
One small hole gets drilled in a mortar joint, a borescope goes through it, moisture readings come off the inside face and each elevation gets walked. All of that lands in a free written itemised quote, with the survey, the system, the junctions and the making good kept on separate lines. For the loft too, see insulation in Broadstone.
The work
Early cavities, and telling a good one from a bad one
The question everything hangs on. Once render is on, a nine inch solid wall and an early brick and block cavity look identical from the road. Down the hole the scope shows the gap and its width, whether it is clean, whether it is dry, whether anything is in there already, and what the wall ties look like. Three answers follow from that, and only one of them is yes.
Yes: the cavity gets filled. Clear, dry, wide enough, ties sound. Material then goes in from outside on a pattern of drilled holes that are made good in matching mortar. On an elevation taking weather that means bonded polystyrene bead, which finds the corners and holds its shape; on a sheltered face blown mineral wool is the older material and does the job perfectly well. Most bungalows in Broadstone run to a single day, all of it inside the reach of a tower.
No: leave the cavity alone. Fifty millimetres is common on a Broadstone wall of this age, and a gap that narrow gives blown material almost nowhere to travel, which leaves voids you cannot see and a wall insulated in patches. Mortar droppings sitting on the ties are just as common and matter more, because a bridge of mortar carries water straight across to the inner leaf and filling around it makes that route permanent. Either one at any scale, and the honest answer is no.
Not yet: deal with the wall first. A slumped fill leaves a cold band at the head of the wall and a wet cavity brings penetrating damp through, black mould arriving behind it. Both read off the borescope. Extraction comes first, the outer leaf gets repointed or repaired where it is letting water in, and the wall is read again afterwards rather than assumed.
Where a no usually leads: lining from inside. Internal wall insulation covers what a cavity cannot help. Insulated plasterboard bonded on, or batten and stud packed out with mineral wool or PIR, then boarded and skimmed. Celotex and Kingspan buy more for the depth given up, and aerogel board is there for a room that has none to give. Reveals, threshold, floor junction and joist ends are wrapped as part of it, because heat in a lined room escapes at the edges rather than through the middle.
Where a no can also lead: the outer face. External wall insulation is board fixed to the outside with a render carrier and a thin coat finish over it, and on a Broadstone bungalow it is unusually easy to reach. One pass lifts the thermal bridge off the corners and the eaves together. The shallow overhang typical of this stock has to be extended to suit, and every reveal, sill and rainwater pipe travels outwards with the wall face.
Whichever branch you end on: the air. Trickle vents in the frames, an extract fan that genuinely moves air, air bricks left clear. In a Broadstone house, insulation shifts the dew point and takes away what draughts were left doing the drying, so a taped vapour control layer and breathable materials hold interstitial condensation out of the fabric instead of letting it gather inside the build up.
How it runs
Filling post-war cavities and lining solid walls
Most Broadstone houses were built after the war with cavity walls, and plenty were filled years ago. Thomas starts by finding out what yours has: a borescope through one small drilled hole shows whether the cavity is empty, partly filled or bridged with mortar. On a bungalow he also checks the exposed gable and the ground level at the damp course.
The quote for a Broadstone house itemises the survey and borescope check, the system and its thickness, making good around windows and doors, ventilation works, and disposal. Cavity fill is drilled and injected from outside by a registered installer, who should hand over a CIGA certificate, then the holes are made good in matching mortar. Internal lining goes room by room with floors sheeted, and the waste leaves with us. If the cavity turns out bridged with mortar, you see the borescope picture and a price before we carry on.
Lining a wall from inside needs no application, as the Planning Portal insulation page confirms. Insulating the outside face changes how the house looks, and its external walls guidance explains when that needs permission, which matters most inside the two conservation areas near the centre shown by BCP Council. Building control is involved either way. Under regulation 23, a renovated thermal element has to reach the Part L standard in Approved Document L, and the inspector looks at the U-value and the ventilation together.
Cost
Filling a cavity and lining a wall are priced differently
Wall insulation in Broadstone is not priced per square metre. The wall area is the easy part. Every window, door and floor junction is not.
Which wall you have. A clear, dry post-war cavity 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. The borescope check settles it before any quote is written.
Access. Cavity fill on a bungalow comes off a ladder or a tower. A chalet gable or a two storey detached needs a taller platform, and the work at height rules set it. Internal lining is worked from inside, so it is your rooms rather than a scaffold that gets disrupted.
The junctions. Reveals at windows and doors, the floor junction, the eaves and any party wall are where heat leaks and condensation shows if the detail is wrong. That slow work is most of the labour, and the first thing a cheap quote leaves out.
What is already in there. An old fill that has slumped or got wet has to come out before a new one goes in.
Ask anyone else whether they have actually looked inside the cavity, what thickness is specified, and who makes good the plaster and decoration.
If damp has appeared
Damp patches on a wall you had insulated
Damp patches or black mould on an outside wall after cavity fill or internal lining usually comes down to rain tracking across the cavity, or warm air reaching a cold spot at a junction. Do not paint over it.
Take a photograph and ring us. On the first visit we look before anything comes out, because the fix depends on which of the two it is, and a borescope often answers that on the day. Planned jobs run Monday to Friday, 8am to 6pm. Please ring rather than fill in the form, and if nobody is there to answer, you will hear back from us as soon as we can manage.
Worth knowing
What a sixty year old cavity actually looks like inside
People picture a neat empty gap. What the camera usually finds on a wall of this age is fifty or sixty millimetres, wall ties every few courses, and lumps of mortar sitting on some of those ties where they dropped off the trowel while the wall was going up and nobody cleaned them off. Sometimes a snapped tie. Sometimes a rusted one. Sometimes a bird's nest at the head of the wall, or debris down at the bottom of it.
None of that is unusual and none of it is a disaster. It does change the advice. Blown material will not travel properly through a narrow, obstructed cavity, so what you end up with is voids you cannot see and a wall insulated in patches. Mortar on a tie is a route for water, and filling around it makes that route permanent.
So on the older half of this village a fair number of walls come back as a no, and the money goes instead into an internal lining on the coldest rooms. A smaller job done properly, rather than a bigger one done hopefully.
Who you are dealing with
Wall insulation in Dunyeats and the Higher Blandford Road side
We are 7.3 miles away in Boscombe. Walls in Broadstone, Dunyeats, the Higher Blandford Road side and the BH18 addresses round them come under Bournemouth, Christchurch and Poole Council for planning and building control. Your contract would be with Bournemouth Roofing & Building Ltd, registered in England and Wales, company number 15471719. Before you book a visit in Broadstone, you can read our customers' Google reviews, word for word, on our reviews page.
Thomas Hannen, the owner, checks the wall and writes up the price in person. Checkatrade shows a 10 out of 10 from a customer they have verified. The visit and the written quote are both free, with each item listed.
Planning at a glance
Do you need planning permission in Broadstone?
Most repairs in Broadstone 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 Broadstone |
|---|---|
| Who decides | BCP Council is the planning authority for Broadstone. BCP Council's heritage pages set out what it controls. |
| Conservation area | Yes: Ridgeway and Broadstone Park Conservation Area and Tudor Road and Golf Links Road Conservation Area. They cover parts of Broadstone, so check whether your street is inside one. |
| Listed buildings | Yes, there are listed buildings in and around Broadstone. If yours is one, work can need listed building consent. |
| Protected landscape | No National Park or National Landscape covers Broadstone. |
Questions
Questions about wall insulation in Broadstone
Someone told me my cavity is too narrow to fill. Is that likely?
On a house of this age, quite possibly. Fifty millimetres is common, and it leaves blown material very little room to travel. The scope measures it instead of guessing from the brickwork.
What are mortar droppings and why do they matter?
Lumps of mortar left sitting on the wall ties while the wall was built. They bridge the gap and carry water to the inner leaf, and filling around them makes that permanent.
Can a narrow cavity be cleaned out instead?
Sometimes, over a limited stretch, but it is disruptive and it rarely stacks up against simply lining the coldest rooms from inside. We will tell you which we think applies.
Do bungalows need a scaffold for cavity work?
No, a tower reaches everything on a single storey house, which is why the access line on a bungalow quote is small next to the same line on a two storey one.
How long does an internal lining take in a bungalow bedroom?
A few days for the boarding and taping, then plastering and decorating after it. The room is out of use while that happens and the rest of the house is sheeted.
Nearby, and next door
Wall insulation near Broadstone
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Wall insulation guides
Damp at the bottom of a wall: what it is PIR board vs mineral wool: which insulation? Hollow-sounding wall: blown plaster or dot and dabEverything we do in Broadstone Wall insulation, all areas Every area we cover
Free quote
Find out whether your cavity can take a fill
Thomas comes out, drills one hole, measures the gap and prices the honest answer in writing. The visit and the quote are free.