Do I have a brick faced Cavity Wall?
This article is written for householders who are not building experts and want to ascertain for themselves if they have a cavity wall or not.
If you have a cavity wall then the option to pump the cavity is open to you. Since Cavity fill is about 10% of the price of External Insulation many people will choose this option. (In terms of quality we prefer to use insulated brick finishes)
There are three tests that a wall either has or does not have a cavity: Building Age, Brick Alignment and Wall Thickness. If all of these tests are passed you can be fairly confident that your wall contains a cavity. However to be 100% certain you should contact a surveyor.
Building Age:
If before 1930 then no, if after 1945 then yes. Cavity walls only came into vogue in the 20th century for waterproofing (Yes, the cavity is to stop water movement) If you have a Victorian home it will not have a cavity.
Brick Alignment: 
If the wall is solid then the bricks will be a mixture of stretchers (Long axis) and “header bricks” (Short Axis): you will see a mixture of sides of brick as in this photo from Ballsbridge.
If there is a cavity you will see that all the bricks are stretchers. IE Have their long axis facing out as in this photo from Rathmines. You will only see short brick around windows, doors and other returns.
Wall thickness:
If you open a window or door you should be able to measure the thickness of the external wall. If the thickness of the wall is about 230 mm you have a solid wall. This corresponds to the long axis of the “header brick” normally 9 inches.
If you have a 300mm thick wall it is probably a cavity wall with two 4.5 inch blocks separated by a 2.5 inch cavity.
With these three simple tests a householder can have a very good idea if their home has a cavity behind their brick fronted wall or not. If there is a cavity you have the option to get the cavity pumped with cavity insulation.
If you would like to talk to us about insulating your walls please contact us.
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