Insulation
Insulating an old building is not the same job as insulating a modern one. Solid walls, suspended timber floors and uninsulated roofs all move moisture as well as heat, and sealing them with impermeable materials traps water in the fabric, causing rot and mould behind the very thing meant to improve comfort. The suppliers and installers listed here work with vapour-open materials – wood fibre, sheep wool, hemp and lime, cork and breathable membranes – and with the detailing that decides whether an upgrade performs or fails. Relevant to retrofit projects, listed buildings and anyone weighing comfort against risk.
What this category covers
- Breathable wall, roof and floor insulation for solid-walled buildings
- Wood fibre, sheep wool, hemp, cork and lime-based systems
- Internal wall insulation detailing and moisture risk assessment
- Draught-proofing and airtightness appropriate to old fabric
- Advice on retrofit sequencing and condensation risk
Ecological Building Systems UK Ltd
Ecological Building Systems supplies natural insulation, airtightness and moisture-management products to the ...
Ecomerchant
Ecomerchant is an independent, employee-owned builders’ merchant supplying natural and sustainable building ...
Green and Heritage Roofing Ltd
Green and Heritage Roofing is a family-run roofing contractor based at Hipperholme, ...
Homes Surveys
Homes Surveys offers fifteen years’ experience advising owners of listed and conservation-area ...
Landmark Windows Co Ltd
Landmark Windows is a family-run joinery workshop at Waltham Abbey, led by ...
Mike Wye Limited
Mike Wye Limited has supplied natural and sustainable building materials from Buckland ...
Mitchell & Dickinson
Mitchell & Dickinson specialise in what they call integrated insulation for period ...
Parsons Building & Maintenance
Parsons Building & Maintenance is a family-run, fully qualified and insured contractor ...
Senergy Heating Limited
Senergy Heating Limited designs, supplies, installs and maintains low-temperature heating and renewable ...
Sheep Wool Insulation Ltd
Sheep Wool Insulation manufactures thermal and acoustic insulation made entirely from natural ...
Insulating an old building without causing damage
Start with the cheap measures. Draught-proofing, loft insulation, heavy curtains and repairing the rainwater goods deliver most of the comfort gain for a fraction of the cost and risk of wall insulation, and none of them threatens the fabric.
If you insulate solid walls, understand where the dew point moves to. Adding insulation internally makes the original wall colder and wetter, so the build-up must let moisture pass and dry out. Vapour-open materials with a hygroscopic buffer, correctly detailed at joists, reveals and floor junctions, are the established approach; foil-faced boards and plastic membranes on solid walls are not.
Ask for a moisture risk assessment on anything substantial. Condensation risk analysis to BS 5250 or a WUFI simulation is standard for internal wall insulation, and any installer proposing it on a period building without one is guessing.
On listed buildings, internal insulation usually needs consent because it alters historic fabric, changes reveals and can conceal features. Discuss it with the conservation officer at design stage rather than after ordering materials.
Questions to ask
Why can't I use standard foam insulation on a solid wall?
Rigid foam and foil-faced boards are vapour-closed. On a solid wall that needs to dry inwards as well as outwards, they trap moisture at the interface, which leads to damp, mould and rot in the wall and any embedded timbers. Vapour-open materials avoid this.
Does insulating a listed building need consent?
Internal wall insulation, and roof insulation that alters visible fabric, normally need Listed Building Consent because they change historic material and can conceal features. Loft insulation between joists and draught-proofing usually do not, but confirm with the conservation officer.
What is the most cost-effective first step?
Draught-proofing and loft insulation, alongside repairing gutters and downpipes so walls stay dry. A dry wall insulates far better than a wet one, and these measures are inexpensive, reversible and carry no moisture risk.
Directory information is provided to help visitors identify potentially relevant specialists and suppliers. Inclusion does not constitute a recommendation, approval or guarantee by Tuscan Foundry Products. Please check current services, credentials, availability and suitability directly with each business.