Internal wall insulation being applied to a cold external wall in a Bath home

Internal wall insulation

Internal Wall Insulation in Bath

Internal insulation for solid walls, cold external walls, bay windows and reveals, using insulated plasterboard or a thinner cork-based system where appropriate.

Sound familiar?

Insulation for Solid Walls, Bays and Reveals

  • One room that never really warms up, however long the heating is on
  • An external wall that's cold to the touch, especially low down
  • Black spotting in the corners or behind furniture each winter
  • Windows running with water first thing on cold mornings
  • A bay window or chimney breast that feels colder than the rest of the room
  • Reveals around windows staying damp or marked when the rest of the wall is fine

Older homes around Bath are often built from solid stone or brick with no cavity, so the inside face of the wall sits cold and moisture in the air condenses on it. Heating and ventilation play a part too, which is why we look at the room as well as the wall.

Mould forming along the base of a cold internal wall before insulation work

The options

Internal Wall Insulation Systems

There isn't one right answer. What we recommend depends on the wall, how much depth you can give up, and whether the build-up needs to stay breathable.

Insulated plasterboard

A rigid, faced board fixed to the wall. Best suited to rooms where you can afford to give up more depth and want the strongest thermal improvement from the build-up. It takes more room off the floor area, and sockets, skirtings and reveals all need reworking around it.

Thin cork-based insulation

A breathable coating trowelled onto the wall and plastered over — see cork insulation. It suits solid and older walls where breathability matters and rooms where losing depth isn't acceptable. Being thinner, the improvement is more modest than a thick board build-up.

A targeted bay, reveal or problem wall

Rather than insulating a whole room, we often treat just the wall, bay or window reveal that's actually causing the problem. It only changes the section you treat, but for a home with one obvious cold spot rather than a house that's cold throughout, that's usually the sensible and proportionate answer.

We don't publish U-values or temperature figures for your wall, because they depend on the actual build-up in front of us. Read more about cold walls and condensation.

How we work

Internal Wall Insulation Installation

Insulation and plastering carried out as one job, start to finish.

  1. 01

    Assess the wall

    We look at the wall, the room and any damp history before recommending anything, and rule out an active leak first.

  2. 02

    Choose the system

    Insulated plasterboard, a thin cork-based system, or a targeted bay or reveal — matched to the depth you can give up and the wall itself.

  3. 03

    Prepare and install

    Sockets, skirtings and architraves come off, the wall is prepared and the chosen system fitted, carried neatly into reveals and bays.

  4. 04

    Plaster and finish

    Plastered to a smooth finish, fittings refitted and the room left clean and ready for the decorator.

Living room in Bath with the insulated walls plastered ready for decoration

A real Bath job — AeroCork case study

AeroCork Internal Wall Insulation in Bath

The walls in this Bath home felt cold to the touch and mould was developing through the winter. We prepared them, applied AeroCork internal insulation and plastered over the top to a smooth finish.

Before insulating anything we rule out a genuine water source — a leaking gutter, failed pointing or a plumbing leak. If you need a different trade first, we'll say so rather than sell you insulation.

Both trades, one contractor

Wall Insulation and Plastering as One Job

We fit the insulation and put the plaster finish on ourselves, so nothing is passed between trades, nobody argues over whose fault a rough patch is, and there's one point of contact for the whole job. Rooms are cleared back and sheeted, sockets and skirtings refitted, waste taken away and the wall left ready for the decorator.

DSB tradesman on site in a room being insulated and plastered

Reviews

What our customers say

Reviews from homeowners around Bath, pulled live from our Google Business Profile, alongside video testimonials filmed after real jobs.

Questions

Internal wall insulation questions

How much room space will I lose?+

It depends on the system. Insulated plasterboard takes more depth than a thin cork-based finish. We measure up, show you the options and let you decide what's worth the trade-off.

Will it stop condensation and mould?+

Insulating the inside face makes the wall surface warmer than the bare wall was, which reduces the conditions that encourage surface condensation. It isn't a guarantee — heating and ventilation still matter, and any leak or genuine damp source has to be dealt with first.

Can you insulate just one wall?+

Yes, and that's often the sensible thing to do. Many homes have one or two problem walls rather than a whole house that's cold.

What about sockets, radiators and skirting?+

They come off and go back on. Sockets are brought forward, skirtings and architraves refitted, and reveals finished neatly around windows.

Do you insulate cold bay windows?+

Yes, where the depth around the reveals and cills allows it and the windows still operate properly.

Request a quote

Get an Internal Wall Insulation Quote

Send photos of the wall and the corners with your postcode, and we'll tell you what's likely going on and what it would take to sort.