Q: What is a Cavity Wall?
The external wall of a house is constructed of two masonry (brick or block) walls, with a cavity (gap) of at least 50mm between. Metal ties join the two walls together
Q: How is Cavity wall insulation installed?
The cavity wall is injected with insulating material by drilling holes in the external wall, approx. 1.5m apart, through the mortar joint. Holes are generally of 22-25mm diameter and are 'made good' after injection. Each hole is injected in turn, starting at the bottom.
A: What about filling the holes?
The Technician will fill all the injection holes with mortar to match the existing as closely as possible. He will use a mix that closely matches the existing colour and texture. On pebbledash finishes, he will apply pebbles to the surface to match the existing finish. After weathering, the holes are difficult to see.
Q: But my house has painted areas
Normally, the installing firm will not paint the injection holes. Unfortunately, even if the original paint is used, it may not match due to weathering. So it may be necessary for you to consider painting the area, after the mortar has dried.
You should discuss and agree what will be done, with the installing firm.
Q: How long will it take?
A: Cavity wall insulation normally takes around three hours to install, but the time does depend on the size of the house and other factors, such as access
Q: Do I have to do anything before installation?
A: The drilling process does create some vibration, it would be wise to remove ornaments from external walls and window ledges, for their safety and your peace of mind. If possible keep pets indoors before installation.
Q: Is there much mess?
A: The drilling process inevitably creates a little dust, which will be cleared at the completion of the job. It may be wise to remove vehicles from the drive and things close to the walls. This will also give the Technician better access for equipment and tools. Remember to warn the neighbours and ask them to keep their windows closed during the process. Take washing in!
Q: Will the work meet regulations and be guaranteed?
A: The work will be guaranteed for 25 years by the Cavity Insulation Guarantee Agency (CIGA). A member of this Agency will be aware of building regulations and the CIGA guide to best practice.