Insulate Bristol - Internal Wall Insulation

Insulate Bristol - Internal Wall Insulation



Frequently asked questions about Internal Insulation

How do I identify if my external walls are solid or cavity construction?

Measuring the width of the wall can help you identify solid walls. The width of the wall can be measured through an open window or door. If the width is less than 260mm, the wall is likely to be solid. Another indication that a property has solid walls is its age, if it was built before 1920 it's likely to have solid walls. You can also tell by looking at the brickwork pattern. If the property is rendered, you may be able to see the brickwork pattern internally in the loft space.

How thick is the internal insulation?

The total thickness of the installation varies depending on the thickness of the insulation board and the installation method, but is typically around 65 mm (depth from the wall) including the plastered finish.

I have black mould on my wall. Will insulation stop the mould returning?

Having black mould on your walls is more than just a cosmetic issue - it likely means you have condensation problems. Solid walls are particularly susceptible to this due to their cold temperature, so insulating them can help reduce the risk of future dampness or mould growth appearing. However, improving ventilation and making lifestyle adjustments may also be necessary.

Will you need to remove the existing plaster before installing the insulation?

No not unless the existing plaster is in poor condition. Leaving the existing intact will act as a 'parge coat' sealing any gaps etc in the masonry which improves air tightness.

How do you insulate window reveals?

Window reveals can be difficult to insulate because of the thickness of the window frame and insulation. We have a few options to try to resolve this issue, for example removing existing plaster from the reveals to gain additional depth to the frame and/or using a thin insulation board designed for hard to treat areas.

Is there a possibility of interstitial condensation?

Condensation risk analysis is required to assess the risk of interstitial condensation, but we do not provide this service. We try to minimise the risk by installing a vapour control layer and sealing any gaps in the installation.

The VCL layer stops warm moist air from inside the house passing through the insulation and condensing behind the insulation, for example on the cold solid wall. The VCL is the first line of defence against interstitial condensation but controlling the moisture levels within the property with adequate ventilation is equally important.

Do I need to remove the radiator?

Radiators will need to be removed from walls to be insulated and re installed after. Pipework may need to be adjusted to allow for the depth of the insulation. 

Will skirting boards need to be removed?

Skirting boards are generally removed. However, if they are still in good condition, they can be reused.

Will I need to relocate electrical sockets?

No electrical sockets can be re installed in the same place once the wall is insulated. Electrical cables may need to extended to allow for the depth of the insulation.

Will I need new window sills?

The insulation may extend beyond the existing window sill. If depth of the window frame is sufficient we can install an over sill. Over sills are available in timber and plastic and they extend the length of an existing window sill so it overhangs the insulation. Sometimes the existing window sill will need to be fully renewed.

How long before I can paint the wall?

When all the plaster turns a light pink colour it is ready to paint. Usually 3-5 days.

What is the best way to paint new plaster?

New plaster requires a priming coat often referred to as a mist coat. The mist coat will penetrate into the plaster providing a good key for further coats.

How do I fix things to the insulated wall?

Plasterboard fixings can be used to fix things to the wall. We would recommend the metal self-drill or gripit fixings.

Can you insulate cavity walls?

Yes. Cavity walls can also be insulated internally. 

Do you install breathable internal wall insulation?

Yes we can install wood fibre board insulation or insulated render. Both are water vapour permeable.