Boost Energy Efficiency with Internal Solid Wall Insulation: 5 Powerful Tips

Enhancing energy efficiency is a top priority for homeowners, and one impactful method to achieve this is through internal insulation for solid walls. Such insulation is crucial for brick, stone, or concrete homes as it significantly reduces heat loss, which typically accounts for about half of a home's energy wastage.

Integrating a thermal layer into the interior side of the wall not only shrinks the room's dimensions slightly but notably amplifies warmth, ensuring a cosier and more enjoyable living space.

This method is especially beneficial for structures where preserving the external facade is essential, like heritage sites. Dive in as we share what is solid wall insulation and 5 powerful tips to maximize the benefits of internal insulation for solid walls.

How To Know If My Home Has Solid Internal Walls?

Determining the type of walls in your home can be figured out in a few ways. If your home's walls are made of brick and display a pattern where bricks alternate between, showing their long and short sides, it indicates a solid wall. On the other hand, if only the long side of the bricks is visible, you're likely dealing with a cavity wall.

The wall's thickness can provide a clue if the bricks are concealed. Typically, a solid brick wall measures around 22cm in thickness. In contrast, a cavity wall falls in the range of 27cm to 30cm, while a solid stone wall can be as strong as 50cm. Another hint lies in the age of your residence. Homes constructed before the late 1920s tend to have solid walls.

What Are The Types Of Solid Internal Wall Insulation?

Internal solid wall insulation methods vary, but they mostly fit into four main categories:

Rigid Insulation Boards

These boards are available in multiple materials and thicknesses, each offering distinct energy conservation features. Some even come with pre-affixed plasterboard, simplifying the installation.

Stud Frames with Infill

For this method, either wooden or metal studs are anchored to the walls. Insulation is then placed between these frames, followed by plasterboard on top. Various insulation materials, like mineral or sheep's wool, wood fibre, hemp, and recycled bottles, can be used.

These robust frames allow heavier fixtures such as bookshelves or kitchen cabinets. They are convenient for evening out irregular walls, like those in some stone-built houses.

Flexible Thermal Linings

Resembling thick wallpaper, these linings are adhered to walls using specialized glue. Although their insulating capability is lower, their ease of installation makes them suitable for DIY enthusiasts. Being typically only up to 10mm thick, they're ideal for tighter spaces.

Insulated Plaster

This is a blend of plaster and insulating elements, like cork. Whether applied with a trowel or sprayed, it's an excellent choice for walls that aren't uniform. Moreover, it significantly enhances the airtightness of a space.

How Does Solid Wall Insulation Manage Moisture?

Solid walls typically allow for vapour movement, indicating moisture can pass through them. When introducing internal wall insulation, you must ensure that you're not establishing a barrier that prevents this natural movement, as this could lead to condensation between the wall and insulation panels.

To manage this, it's recommended to use breathable insulation materials and finishes which permit moisture transfer between the interior and exterior.

Materials such as wood fibre are expert at regulating and dispersing moisture, preventing it from being confined within the wall. This helps avoid issues like dampness, mould, and potential structural damage.

However, it's equally important to ensure the accompanying plaster is vapour-permeable when using such materials. Pairing breathable insulation with a non-permeable plaster would offset its benefits.

Another approach involves using less permeable materials to create an unbroken vapour barrier, ensuring moisture doesn't seep between the insulation and the walls. For this method, consulting a specialist installer for guidance is advisable.

Valuable Tips To Install Internal Insulation For Solid Walls

Here are our five valuable tips for installing internal wall insulation effectively:

1: Address Dampness and Windows Beforehand

Ensure any damp issues are thoroughly resolved before installing the solid wall insulation. Additionally, consider installing new windows with thicker frames for enhanced thermal efficiency.

These frames can integrate seamlessly with the insulation and the window fittings should be adjusted for the insulation's thickness.

2: Preservation of Architectural Features

If your home has period elements like coving, be ready for some changes. Insulation can conceal these features, requiring specific modifications or recreation to preserve their aesthetic.

3: Electrical and Fixtures Preparations

Before insulating, it's advisable to set up additional plug sockets. Utilize plasterboard back boxes during this phase to ease the installation of sockets post-plastering.

Meanwhile, plan for heavy fixtures like curtain poles, ensuring the necessary support is in place behind the insulation.

4: Radiators and Other Installations

Introduce radiators after insulating your solid walls. However, radiator piping might need extension ahead of this, adding to the insulation thickness.

Furnish your insulation team with radiator dimensions, especially fixing points, to facilitate installation.

5: Consideration for Ventilation

Enhancing energy efficiency can occasionally result in condensation issues due to reduced ventilation in older homes. If this arises, seek guidance on mechanical ventilation solutions to maintain optimal indoor air quality.

How Much Does Solid Wall Insulation Cost?

The typical expense for implementing internal solid wall insulation in an average 3-bedroom, semi-detached home hovers around £8,500. This cost can vary based on the number of rooms undergoing renovation and the insulation material chosen.

Opting for internal over external solid wall insulation usually saves cost, given the reduced material and labour expenses.

The anticipated annual savings for homes heated by gas are approximately £475 on heating expenses. In the case of a detached house, the annual savings could amount to roughly £603, as per data from the Energy Saving Trust and National Housing Model.

Read more: How to Read Your Gas And Electricity Meter?