Questions and answers about Cavity Wall Insulation

What is a cavity wall?
The external wall of a house is constructed of 2 masonary (brick or block) walls, with a cavity (gap) of at least 50mm between. Metal ties join the 2 walls together.
What is the material – does it smell?
Material is environmentally friendly bonded beadand has no odour
Will it spread damp?
No it is a dry, waterproof material that allows the walls to breath.
How is it installed?
Blown in via small holes in the mortar under compressed air pressure
How much heat does it save?
35% of heat is lost through the walls of un-insulated homes
How much does it cost?
It depends upon whether you are in receipt of qualifying benefits or not. See SEI website for details.
Does the work have a guarantee?
Yes – all work is NSAI and SEI Certified.
How long does it take?
Approx 3 hours for a 3 bed semi
Is my house suitable?
A free assessment is undertaken by our surveyor to determine suitability
Is there much mess?
The process inevitably creates dust, which the technicians will clear up at completion.
Does the technician have to come into the house?
Yes both pre and post installation checks are necessary including all heating appliances, apart from these checks the work is normally carried out from outside
My house is semi-detached, how do you stop the material going into my neighbour’s cavity?
Assuming your neighbours house is not insulated, the technician will insert a cavity barrier consisting of a bristle brush at the party wall line
What insulation material is used?
We use Enviro Bonded Bead because it is simple to install. The material has been tested, assessed and approved by the NSAI Agrements.
Are the technicians trained?
Yes all technicians (team leaders) undergo training by the system designer and Complete Insulation to ensure they are competent and carry a training card.
How do I know the walls are full?
The system has a defined pattern of holes, which has been tested to verify that it results in a complete fill. There is a tolerance in the injection pattern so that the material will flow past the next injection hole
Is the insulation dense?
No, as the insulation is contained in a masonry wall it doesn’t have to be dense. Indeed for insulation purposes a light density is better. Before installation the Technician will undertake a quality test to ensure the insulation will go into the wall at the right density. He will also note the amount of material used, to know that sufficient insulation has been installed.
What about the ventilators that are in the external wall?
Ventilators supplying combustion air to fuel burning appliances must be safeguarded. Similarly ventilators at ground level that ventilate below timber floors must be safeguarded. The Technician will investigate them to check they are sleeved. If they are not, the Technician will remove them and seal around them to stop them being blocked by the insulation material. Other vents, which may be redundant, such as cavity vents or vents that used to supply air to open fires in bedrooms may be closed off
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 finish, he will apply pebbles to the surface to match the existing finish. After weathering the holes are difficult to see.
My house has painted areas?
Normally we will paint the holes although a close match is unlikely due to weathering. It may be necessary to paint the area after the mortar has dried.
Will my house be warmer?
Yes – you should find that your home holds its temperature for longer; therefore the time between heating cycles may be longer. The result should be a more even temperature throughout the house and/or a reduced fuel bill
How long will the insulation last?
For the life of the building