Wall Insulation 

Benefits of Thermal Wall Insulation

Thermal wall insulation acts as a barrier to heat flow and is needed to keep your home cool in summer and warm in winter. Properly installed insulation can reduce greenhouse gas emissions and heating bills by up to half, as well as improve the overall comfort of your home. This diagram shows how 18-25% of heat can be lost through the walls of an uninsulated home.

The main thing to keep in mind when considering installing wall insulation, is that once the walls are lined, the job it done, and you won’t be in a hurry to dismantle the wall to redo the wall insulation. So it’s imperative to ensure that

1. The correct R-value is installed the first time
2. The insulation is installed with a neat finish, with minimum air-gaps.

At Pricewise insulation, we recommend upgrading your wall insulation to at least one ‘R-value’ higher than the minimal mandatory specifications on your report. The required total R-value for the building fabric of your home will vary depending on your climate zone.

Upgrading from R2.0 to R2.5 external wall insulation

Upgrading to an R2.5 wall insulation batt will improve both the thermal and acoustic performance of your home. These batts are rigid and fit snugly between the wooden joists to achieve an optimal thermal finish. R2.5HD Knauf Earthwool is a high density product with higher acoustic ratings than your typical R1.5 or R2.0 wall batts.

Can I use R2.5 ceiling insulation for walls? It’s cheaper!

You might have noticed a difference in pricing between the R2.5 wall batts and R2.5 ceiling batts. Achieving an R2.5 rating within a 90mm product requires an increase in product density, hence the higher manufacturing costs. A typical R2.5 ceiling insulation batt is 125mm thick and not suitable for a wall cavity. Trying to compress the insulation into a 90mm cavity will cause the plaster to bow and will also reduce the thermal performance of the batt. If bulk insulation is compressed, so are the air pockets within it that provide the insulation. This means it will not work as effectively as it should, hence this approach is never recommended.

Which insulation brand is best?

Earthwool vs Pink Batts vs Bradford Gold

In the end the most important consideration is what R-value to use, not the brand. Knauf Earthwool, Pink Batts and Bradford Gold are all good quality brands, each with their own benefits.

The main thing to know is that products with the same R-value all have the same thermal performance if installed as specified. An R2.0 Knauf Earthwool Insulation Segment will provide the same thermal resistance as an R2.0 Fletcher Pink Batt or an R2.0 Bradford Gold.

In saying this, we do not recommend brands such as Ecowool Insulation that are manufactured in Asia. We find these are inconsistent in quality and irritable to the skin.