If you have walls with cavities in your property (see below), having them filled with insulation is one of the most cost
effective ways of reducing your ongoing fuel bills and improving the comfort of your home.
The walls of most homes account for the largest single area of heat loss, even larger than the windows and roof and
insulating these areas can save you up to 33% off your heating bills.
The simple procedure of filling your cavity with Rockwool Cavity Wall Insulation will result in a significant reduction in
heat loss. This means that less fuel is needed to obtain the same level of comfort throughout your home, therefore
reducing your heating bills.
Cavity wall insulation is designed to reduce the down draughts created from the outside wall, and also helping out with
Often the thought of having your cavity filled with insulation can be quite daunting, when in-fact the process
is relatively easy.
Most houses built after 1930 (and before 1990) will have cavity walls. Most older properties will have solid walls so
would need external wall insulation. Houses built after the mid 1980’s are likely to have cavity wall insulation
If you think your property is around the right age you can often tell if you have cavity walls by looking at the brick
pattern: all the bricks in each course layered lengthways, end to end with no headers (end of bricks) as below:
However if the brick pattern is alternating between length-ways and end-on your wall is solid, without a cavity so you
will need to look at External Wall Insulation:
If you are unsure whether your home can benefit from the advantages of Cavity Wall Insulation, one of our experienced
surveyors will instantly give you the answer, simply call 020 8285 6076 or contact us
Cavity Walls were introduced to reduce the risk of water penetration. Filling the cavity with Rockwool will create a
‘composite construction’ and does not alter the walls performance when it comes to keeping out the weather.
In fact recent research indicates that homes with Rockwool cavity wall insulation are in fact less prone to damp as
Rockwool allows the walls to “breathe”.
Installing Rockwool Insulation is a relatively straightforward process.
Firstly an experienced Puffin surveyor will visit your property to confirm that it is suitable i.e. in good condition, has wall
cavities that can be filled and that your property is not in an area designated as suffering from windblown rain.
We will then provide a quotation to complete the work and go through the information with you to make sure you are
happy with the proposed work.
If you accept the quote the installation will consist of a small team of CWI installers who will, starting from the base
of your property, drill small holes at pre-determined distances (normally about 1.5 m apart) through the mortar joint
between the bricks and insert a nozzle to “blow” the mineral wool into the cavity.
They will move along the wall until all it has been filled at that level then move up the wall (again about 1.5 m)
and start again.
The installers will make sure that an even pattern is used across the face of the wall and that the highest hole is no
more than 30cm from the top of the bricks. This ensures that the cavity is filled evenly from the bottom to the very top.
The holes are then filled with mortar and made good to make sure the end result is nearly invisible.
This process is applied to each and every wall where it is required.
Once complete the area will be tidied as if we were never there.
Our experienced and helpful staff will always be happy to assist you.