Wall insulation in Langton Matravers
Solid Purbeck stone lined from the inside in a build up that still lets the wall dry, with the reveals and floor junction detailed, across the village and BH19.
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 Langton Matravers usually means lining, because the older houses are Purbeck stone and a Purbeck stone wall is solid. There is no cavity in it, so there is nothing to fill, and any firm offering to inject one is selling you a drilled wall. The honest options here are lining the inside, insulating the outside, or leaving the wall alone and spending the money elsewhere.
The trouble in a Langton Matravers stone cottage tends to take the same shape. A room on the south west corner that never feels warm however long the heating runs. Black mould behind a wardrobe. Or a cottage where somebody has already put insulated plasterboard on one wall and the damp has moved next door.
We look at what the wall is made of, inside and out, before anyone talks about systems. Then it goes into a free written itemised quote with the survey, the build up, the reveals and the making good on separate lines. For the loft and draughts, see insulation in Langton Matravers.
The work
Stone walls, and the lining that suits them
Finding out which wall you have. Rubble stone, nine inch solid brick and a later brick and block cavity all sit within a few hundred yards of each other here, and plenty of houses are one at the front and another at the back.
We measure the wall thickness at a reveal, look at the bond, and where a cavity is possible we drill one hole and put a borescope in. That check stops the most expensive mistake in this trade.
Internal wall insulation. On a solid Langton Matravers stone wall this is the practical route. Either insulated plasterboard bonded and mechanically fixed back, or a stud and batten frame with mineral wool or PIR board between it. On Purbeck rubble the wall face is rarely flat, so a batten frame packed to line beats dabbing a board onto a lumpy background. It takes 60 to 100mm off the room, which is why we set it out on paper first.
Breathability, and why it matters more here. A Langton Matravers stone wall gets wet in a south westerly and dries out afterwards. Seal a foil faced board hard onto the inside of it and the wall can only dry outwards, so in a driven rain winter it stays wet and the dew point ends up inside the build up. That is interstitial condensation, and it rots joist ends quietly for years before anything shows. BS 5250 is the code of practice that deals with it. On old masonry we favour a breathable lining, wood fibre or a mineral wool build up with a vapour open finish, so moisture can still pass.
The junctions decide it. A lined Langton Matravers wall that stops at the plaster line leaves a cold bridge at every window and door reveal, at the floor junction and at the party wall. Those are where black mould appears afterwards. Reveals get returned with a thin board, often aerogel backed where the frame leaves no room, and the lining is carried past the junction.
External wall insulation, and where it is not an option. Boards, a render carrier and a thin coat finish outside gives the best U value and no loss of room, but it buries the stone. On a stone elevation in the conservation area that is not a realistic proposal, and we will say so rather than take you through an application that will fail.
Cavity work on the newer houses. Post war housing in Langton Matravers does have a cavity, and where the borescope shows it clear and dry it takes bonded bead or blown mineral wool in a day. Failed or slumped fill is extracted through the drilled holes and replaced. Whatever the wall, we look at extract fans and trickle vents in the same visit, because airtightness without ventilation is how you make a mould problem.
How it runs
Lining solid stone walls so they can still dry out
Thomas establishes what the walls are before he prices anything. A Purbeck stone wall is solid and cannot take cavity fill. A later cavity wall may, once a borescope through a small hole has shown it clear and dry. His quote lists that survey, the insulation and its thickness, making good at windows and doors, ventilation, and waste.
On a later house with a cavity, a fill is injected from outside by a separate cavity installer rather than by us. Lining a stone wall happens room by room: furniture moved, the wall prepared, breathable boards or mineral wool fixed and finished in lime or plasterboard, reveals made good. Near the coast, driven rain on the south west wall has to be stopped first, through pointing or render, or the lining traps the wet. Waste leaves each day. If damp or rot turns up, you see a picture of it and the cost of putting it right before lining starts.
Lining a wall inside cannot be seen from the road and needs no planning permission, which the Planning Portal page on insulation confirms. Insulating outside alters the face of the building, and the Planning Portal guidance on external walls explains when that needs consent, so check with Dorset Council, as the village is covered by the Langton Matravers Conservation Areas 1 and 2. A listed building needs listed building consent even for internal lining, and renovating a thermal element brings building control in under regulation 23.
Cost
Cavity or stone: what a wall insulation quote depends on
Wall insulation is not priced per square metre, and the junctions cost more than the open wall. Which wall. An empty, dry cavity can be filled quickly. A stone wall has no cavity. It must be lined on the inside, or clad outside, using materials that let it breathe, which is far more work.
The weather side. On an exposed south west wall near the sea, driven rain and salt are dealt with first, by pointing, render or a lime finish, before any lining goes in.
The junctions. Window and door reveals, floors, eaves and party walls are where heat leaks and condensation gathers if the detail is careless. That slow work is most of the labour.
Access. Cavity fill on a bungalow works off a tower. A taller gable needs scaffold under the work at height rules.
Putting rooms back. Sockets, skirting, radiators and window boards come off and go back, and the walls are left ready for decorating.
Questions for any other quote: did they look inside the wall with a borescope, and what system and thickness they propose, how the reveals are finished, and who makes good afterwards.
If damp has appeared
Mould or damp on a wall since it was insulated
If an outside wall has shown damp or black mould since it was insulated, ring rather than use the form. On a cavity wall, the fill may be carrying rain across. On a lined stone wall, warm air may be reaching a cold surface at a junction.
We look before taking anything out, because the cure depends on the cause. On the seaward side, check the pointing and render outside as well. Scheduled work is Monday to Friday, 8am to 6pm. Should you reach voicemail, leave your number and we will be in touch once we are free.
Worth knowing
A Purbeck wall has to be allowed to dry
Purbeck limestone laid in lime mortar behaves nothing like a modern cavity wall. It takes water in through the face in a wet south westerly, holds it, and gives it back through both faces once the weather turns. The wall has done that for two hundred years. What it cannot cope with is being sealed on one side.
This changes the specification in one way. The cheapest internal lining on the market is a foil faced PIR board dabbed straight onto the wall, and on a solid stone elevation facing the weather it is the wrong product. The foil is a vapour barrier on the warm side, the dabs leave voids behind the board, and warm moist air finds the cold masonry through the gaps at the edges. What comes back is damp at the skirting and mould on the reveals.
So on stone we line with a build up that stays vapour open, fixed to battens rather than dabs so there is no unventilated void, and we sort the outside first. Repointing in lime rather than cement, a working gutter and a downpipe that is not soaking one patch of wall take more heat loss out of a cottage than the first 25mm of insulation does, and the payback is quicker. So is an afternoon spent on the draughts around the doors.
Who you are dealing with
Wall insulation in Kingston, Worth Matravers and BH19
At 11.2 miles from our base in Boscombe, the village is well within our area. We insulate walls in Langton Matravers, in Kingston and Worth Matravers, in Swanage and at the BH19 addresses round them, with Dorset Council as the local authority.
The company is Bournemouth Roofing & Building Ltd, registered in England and Wales, company number 15471719. Before anything is drilled, Thomas Hannen, who owns the firm, checks your walls and prices the job. Look on Checkatrade and you will find a verified customer's 10 out of 10. We charge nothing for the survey or the written quote, which is itemised. Before you book a visit in Langton Matravers, you can read our customers' Google reviews, word for word, on our reviews page.
Planning at a glance
Do you need planning permission in Langton Matravers?
Most repairs in Langton Matravers 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 Langton Matravers |
|---|---|
| Who decides | Dorset Council is the planning authority for Langton Matravers. Dorset Council's heritage pages set out what it controls. |
| Conservation area | Yes: Langton Matravers Conservation Area 1, Conservation Area 2 and Acton Conservation Area 1 and 2. They cover parts of Langton Matravers, so check whether your street is inside one. |
| Listed buildings | Yes, there are listed buildings in and around Langton Matravers. If yours is one, work can need listed building consent. |
| Protected landscape | Inside the Dorset National Landscape (formerly AONB), so anything visible from outside gets more attention. |
Questions
Questions about wall insulation in Langton Matravers
Can a Purbeck stone wall be cavity filled?
No, a Purbeck stone wall cannot be cavity filled. It is a solid wall with no cavity in it, so there is nothing for the bead or the fibre to go into. Drilling it only puts holes in good stonework.
What is the best insulation for a solid stone wall?
Something vapour open, fixed to battens rather than dabbed on. Wood fibre or a mineral wool build up lets the wall carry on drying inwards, which a foil faced board does not.
How much room will an internal lining take off?
Between 60 and 100mm on each wall that gets done, less at reveals where we use a thinner high performance board. We set it out before ordering so you can see what it does to the room.
We are in the conservation area. Can we insulate outside?
Almost certainly not on a stone elevation. External insulation buries the stone and changes the appearance, which is exactly what the designation controls. Internal lining is the route that gets consent.
Can we line one room at a time?
Yes, and it is often the sensible way to start. Begin with the coldest rooms on the weather side, live with it a winter, then decide. It also keeps the house usable, and it still shows on an EPC.
Nearby, and next door
Wall insulation near Langton Matravers
Nearby places we also cover for wall insulation, with straight-line distances from Langton Matravers, and the other trades we offer in Langton Matravers itself.
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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 Swanage Wall insulation, all areas Every area we cover
Free quote
Find out what your walls are made of first
Thomas comes out, works out whether you have stone, solid brick or a cavity, and prices only the work that suits it. The visit and the written quote are both free.