Internal thermal insulation

Internal thermal insulation is an effective way to improve comfort and energy efficiency when exterior insulation is not possible. It helps reduce heat loss through walls and ceilings, limits cold surfaces that cause drafts, and can make rooms feel warmer with less heating. This service is ideal for apartments, listed buildings, shared facades, or any property where external changes are restricted.

Done correctly, internal insulation also supports better acoustic comfort and can help manage condensation by controlling temperature differences on interior surfaces. Our team designs and installs systems that match your building type, room usage, and long term performance goals, with careful attention to detail around corners, sockets, and junctions.

Where internal insulation works best

Internal insulation can be installed on external facing walls, under roof slopes, and on ceilings below unheated spaces. It is commonly chosen for renovations where rooms are being updated anyway, or where you want targeted improvements in bedrooms, living rooms, or home offices.

Solid masonry walls that feel cold to the touch and are prone to surface condensation
Top floor ceilings below uninsulated attics or poorly insulated roof spaces
Basement and ground level rooms where walls are cooler and humidity risk is higher
Partial upgrades where only certain elevations or rooms need improvement

Internal insulation may not be the right solution for every property, especially if there are existing moisture problems. We always assess the condition of the substrate, ventilation levels, and heating patterns before recommending a build up.

Our approach, survey, design, and installation

Assessment and preparation

We begin with a site survey to understand heat loss areas, wall composition, and any signs of damp or salt contamination. We check window reveals, radiators, and existing finishes to plan a continuous insulation layer and reduce thermal bridges. If needed, we recommend minor remedial works such as improving ventilation or repairing damaged plaster before installation.

System selection and build up

Depending on your needs, we install insulated lining systems that combine insulation with a stable internal finish. Options may include rigid boards, mineral wool within framing, or high performance composite panels. The chosen solution is designed to balance insulation value, room space impact, and moisture safety.

Many projects require new lining walls or ceilings as part of the upgrade. We can integrate insulation with interior wall construction so the final result is straight, durable, and ready for decorating. For upper floors and apartments, we also coordinate insulation works with drywall ceiling installation to improve thermal comfort and hide services cleanly.

Installation details that protect performance

Quality is defined by the details. We seal gaps, align layers precisely, and treat junctions where heat loss is most common, such as wall to ceiling edges, window recesses, and service penetrations. Where appropriate, we incorporate vapour control layers and airtightness measures to help prevent warm indoor air from reaching cold surfaces inside the build up.

Benefits you can expect

Lower heating demand with reduced heat loss through external facing elements
Improved comfort from warmer wall surfaces and fewer cold drafts
Better condensation control when combined with correct vapour management and ventilation
Quieter rooms as insulation and linings can reduce airborne noise transfer
Cleaner finishes with refreshed walls and ceilings ready for paint or wallpaper

Internal insulation is also a practical choice for staged renovations. You can upgrade one room at a time, coordinate work around occupancy, and keep external appearance unchanged.

Common concerns and how we handle them

Space loss

Any internal insulation reduces room dimensions slightly. We help you choose thicknesses that achieve meaningful performance without unnecessary impact, and we plan details like skirting, coving, and window boards so the finished room still looks balanced.

Moisture and mould risk

Insulating internally changes the temperature profile of the wall. That is why we assess moisture risk and specify appropriate materials and membranes. We pay particular attention to airtightness and continuity, because small leaks around sockets or edges can lead to localised cold spots.

Electrical and heating adjustments

Sockets, switches, and radiators may need repositioning. We coordinate these changes and provide neat finishing so the upgrade looks intentional, not patched. If you are planning broader renovation works, we can align insulation with wall and ceiling finishing to streamline trades and reduce downtime.

What you receive

On site survey and practical recommendations based on your building and goals
Clear scope of work including build ups, finishes, and any enabling works
Professional installation with careful sealing and consistent detailing
Ready to decorate surfaces with clean lines around openings and junctions

If you want warmer rooms, lower bills, and a more comfortable home without changing the exterior, internal thermal insulation is a smart and durable upgrade when designed and installed with care.

FAQ

How long does internal wall insulation take to install in one room?

A typical room can take 2 to 5 days depending on wall condition, the system thickness, and whether electrics or radiators need moving. We confirm a schedule after the site survey.

Will internal insulation help with mould on cold walls?

It often helps by raising the surface temperature, which reduces condensation risk. However, mould can also be caused by poor ventilation or existing damp, so we assess those factors and specify the right vapour control and sealing details.

Do I need to move out during the works?

In many cases you can stay in the property, especially if the work is limited to one or two rooms. There will be dust and some disruption, so we plan access, protection, and drying times to keep the home usable.