How is Cavity Wall Insulation Installed?


This guide explains how cavity wall insulation in installed. It is based on the use of mineral wool insulation such as rockwool or whitewool. Please  note that the procedure may vary between insulation manufacturers and installation companies.

Call 020 8133 0851 for a free survey


Before the work is undertaken a throughout survey is carried out to ensure that the building is suitable for insulation. This may involve drilling test holes into the outer leaf of the brickwork and inspecting the interior of the cavity to check that it is clear of any debris and of a sufficient width to allow the material to spread evenly within it.


The first step in carrying out the work is to drill a pattern of holes through the outer leaf of the walls. These are drilled into the mortar line, where will be less visible when the work is completed. The hole size is typically around 22-25 mm.

  Cavity wall insulation drill hole pattern

The pattern varies between different insulation systems but the holes are typically around 1.35 meters apart and at set heights up the wall, starting below windowsill level and working up to the top of the wall. The pattern used for polystyrene beads in particular may not include filling to the peak of gables, where the loft space is unoccupied.


To prevent spillage of material into the cavities of adjacent properties, in the case of semi-detached or terraced houses, full length brushes are placed in the cavity to form a permanent barrier between the houses. These are pulled up through the cavity from a small hole at the base of the wall and are left in place after the work is complete.


Grants for Cavity Wall Insulation

The loose wool insulation is blown into the cavity until it is tightly packed and no gaps are left, at which point a pressure sensor on the blowing machine cuts off the flow of material. The process begins at the bottom of the wall. Wool is then back filled through the holes across the wall and the process continues in layers up the wall.


Under floor ventilation is maintained by 'sleeving' air vents where necessary. Any chimneys and air intakes for heaters and gas appliances are also checked and sleeved where necessary to maintain ventilation.


All holes are filled with matching mortar to complete the work. In most cases the whole job can be complete in under half a day.


To find out more about have cavity wall insulation installed in your home and about grants that are available to help with the cost of having the work carried out, please contact us on 020 8133 0851 or email us to arrange a free survey.



Home | Cavity Wall Insulation Companies | Loft Insulation Installers


CS Design Services, 33 Kensington Gardens, Darlington, DL1 4NG, United Kingdom
Web site development by CS Design Services of Darlington
Copyright 2012 CS Design Services. All rights reserved. Terms & Conditions