Internal Wall Insulation

Professional insulation services

Internal wall insulation

Internal wall insulation can be carried out using polyurethane foam, amino injection foam, or blown insulation wool.
According to building regulations and industry experience, it is generally recommended to insulate walls from the outside. One of the main drawbacks of internal insulation is the loss of usable floor space. However, there are situations where external insulation is not possible.
Internal wall insulation can be carried out using several methods, but it is essential to follow proper installation techniques. It is commonly applied using polyurethane foam or spray-applied (blown) insulation materials.
Before starting internal insulation, it is important to assess the location of electrical outlets, radiators, skirting boards, and other existing elements.
When insulating from the inside, it is not enough to insulate only the walls. It is also important to insulate adjacent structures such as: parts of floors (ceilings), connecting walls. Additionally, it is recommended to insulate: window and door reveals, lintel areas.

Why is it worth insulating walls from the inside?

Internal wall insulation is an effective solution for improving energy efficiency when external insulation is not possible. It helps reduce heat loss, lower energy bills, and create a more comfortable indoor environment. This method is especially suitable for older properties, flats, or buildings where the exterior must remain unchanged.
Modern insulation materials such as polyurethane foam and blown insulation adapt easily to wall structures, ensuring good thermal performance and reduced drafts. When installed correctly, internal wall insulation also helps minimise cold surfaces and improves overall living comfort, making it a practical choice for upgrading your home’s energy performance.

How can you save money by insulating walls from the inside?

Internal wall insulation can significantly reduce heat loss, which helps lower energy consumption and heating costs. By creating an additional thermal barrier, less heat escapes through the walls, meaning your home requires less energy to maintain a comfortable temperature.
Savings can be maximised by using high-performance insulation materials such as polyurethane foam or blown insulation, and by ensuring proper installation without gaps or thermal bridges. Well-insulated walls also improve indoor comfort, reduce drafts, and help maintain a stable temperature, leading to long-term energy savings.

Proper detailing is essential. If adjacent areas are not insulated, surface temperatures in corners and junctions will be significantly lower, increasing the risk of condensation and potential mould formation.

Best Materials for Attic Insulation

Blown Loose-Fill Insulation (Mineral Wool / Fiberglass)

Blown insulation is a flexible and breathable solution for internal wall insulation, installed using specialised equipment to evenly fill cavities and hard-to-reach areas. Materials such as mineral wool, cellulose, and wood fibre are vapour permeable, helping to regulate moisture and reduce the risk of condensation and mould.
This type of insulation adapts to irregular surfaces, minimising thermal bridges and ensuring consistent coverage. It also offers good sound insulation, fire resistance (mineral wool), and eco-friendly options, making it a reliable and efficient choice for modern buildings.

Polyurethane Foam Insulation

Polyurethane foam is a high-performance insulation material applied as a liquid that expands into a seamless layer, eliminating gaps and reducing heat loss. It offers excellent thermal performance with a thinner layer and creates an airtight barrier that prevents drafts. The material is also moisture-resistant, ensuring long-term durability and reliable insulation.

Aminoplast (Injection Foam) Insulation

Aminoplast injection foam is a specialised insulation material designed for filling wall cavities. It is injected in liquid form, flowing easily into voids and ensuring full coverage without expansion pressure on the structure.
This breathable insulation allows walls to “breathe,” helping to control moisture and reduce the risk of condensation. It is a safe and effective solution for older buildings and cavity wall insulation