Why does cavity wall insulation need removing and how is it done?

Why does insulation need removing?

Cavity wall insulation is a ‘system’ which when installed correctly is completed so that the entirety of the cavity void is filled. 

There are however a number of factors which can impact the insulation integrity such as the below

  1. Debris in cavity before insulation installed causing voids in insulation
  2. Escape of water – leaks within the property can cause the insulation inside the walls to get wet
  3. Damage to walls
  4. changing windows and doors can lead to insulation falling out
  5. Failed render/poor brickwork or mortar joints can lead to water ingress
  6. Fire at a property can cause damage to insulation

All of the above are factors to a cavity wall insulation system failing which results in a cavity clearance being needed to prevent water ingress and damp from entering the property and specialist advice should be sought 

How is the insulation removed?

There is a tried and tested method to removing failed Cavity Wall Insulation material from external cavity walls of properties. The system will remove any ‘blown-in’ material or problem cavity debris and create a clear cavity that can be re-insulated or left clear if it is not suitable for this type of insulation.

The procedure involves creating a low level cavity access points in the extraction area by either removing bricks/masonry or by core drilling to allow access to the cavity with the extraction lance. The debris/insulation material is removed from the cavity by a specially developed air extraction unit system, assisted by a combination of compressed air and whip/flail devices.

Process Steps:

  1. Bricks are removed one course above dpc approximately 3m away from each other along the bottom of the wall.
  2. The original drill/injection holes are detected and access holes are then re-drilled out using a downwards sloping angle to enable an air lance to be inserted to propel material in a downwards direction to the footings. It may be necessary to drill additional holes to ensure all material is cleared.
  3. Industrial vacuum pipes are inserted into locations where bricks have been removed and seal around pipe so agitated material can only be sucked out through and into vacuum pipe.
  4. Compressed air is then blown into the drilled out holes to start moving the material to the exit points and an agitating whip is inserted into the cavity to break up the material
  5. Ongoing checks are completed with a borescope to look inside the cavity to ensure it is fully clear
  6. The bricks removed at the bottom of the wall are then replaced and the area cleaned from all dust.

What Type of cavity walls can be extracted?

All types of properties that were built of cavity construction can be cleared including materials such as Mineral fibre, Polystyrene beads and Urea Formaldehyde Insulations

Posted on: May 25, 2018, by : cwip_admin

Leave a Reply

Your email address will not be published. Required fields are marked *