Month: May 2018

Do You Suffer From Issues With Your Cavity Wall Insulation?

Are you experiencing problems?

Sometimes, your cavity wall insulation can develop and show signs that they are faulty. Damp could occur in properties as a result of cavity wall insulation if there is a combination of these factors:
• Your home is exposed to severe weather conditions
• Your home is located in an unsheltered position, e.g. not protected by other buildings or by trees
• The external walls are poorly built, e.g. cracks in the brickwork

If you had cavity wall insulation installed a long time ago, it could be possible that Urea-formaldehyde may have been injected into your cavity wall. This is a type of foam which, over a number of years, degrades and can become harmful to your health through a combination of gas released from the foam and damp – most properties have had this removed, but this can be very dangerous if it is left to stay.

There have been a number of occasions where the cavity wall insulation has been fitted into houses which aren’t suitable, like steel or wooden framed properties. For properties constructed with brick which are in poor condition or are in areas subject to wind-driven rain, e.g. near the coast, problems caused by cavity wall insulation can also occur as it is believed that properties near the coast should not have insulation installed in the first place.

There can be an increased risk of rain penetration if a cavity is fully filled with insulation. Rainwater can penetrate the outer layers of brick leading to the cavity insulation becoming wet. This then leads to the moisture transferring to the inner leaf of the cavity and causes it to become wet. This then leads to reduced heat and damage to internal furnishings in your home, especially if they are close to the wall.

When a property has been flooded, the cavity wall insulation can become wet and is likely to dry out leading to problems of damp inside a property. Similarly, in the event of a fire, the high levels of water used to extinguish the flames may also water-log the cavity wall insulation, as well as the fire damaging the insulation itself in the blaze. This may be potentially dangerous, as the material may emit gases as it is burned.

If the insulation has been installed poorly, there can be gaps where the insulation hasn’t reached as not enough was pumped into the cavity. Some problems which you may have noticed include:

• Cold spots on external walls
• Internal damp problems
• Mould growth
• Damaged cavity wall insulation
• Wet cavity wall insulation

If your cavity wall installation has any of these problems, contact an expert today for help and advice.

Types of Damp and Condensation

Damp and condensation can blight any home, take a look at this guide on what type of damp you are suffering from and how to banish for good..

The most common forms of damp are Condensation, penetrative damp and rising damp. Treating them can vary massively and so can the costs so it is worthwhile investigating what you are suffering from to keep the costs down for the repair works

Penetrative damp 

Penetrative damp is where there is water ingress to inside of the property through the transference of water from the outside to the inside skin of the wall and moves through the wall rather than upwards.

Water can penetrate through walls for a variety of reasons, most commonly from failed cavity wall insulation, leaking roof along the top of the wall, faulty guttering or failed render.

The damp is seen in the form of wet patches on the wall and the repair work can be localised to this area to establish the reason by looking outside in this area to see what is failing.

Repair costs to guttering is cheap and easy to remedy, if you have a cavity wall constructed house however, it may be necessary to remove the cavity insulation from the property if it has failed


This is the most common form of damp within homes in Britain. Condensation is formed from warm moist air condensing on a cold surface and is seen in the form of black mould spores on walls and window frames which can be hazardous to health through respiratory problems.

There can be many reasons for condensation forming but most commonly it can be brought back to insufficient ventilation in a property.

To complete a check of your homes, it is worth looking at the two areas which produce the most moisture in the homes in the bathroom and the kitchen where extractor fan ventilation is imperative to remove the warm moist air before the condensation can form.

If you still suffer from condensation around windows, it is beneficial to add extra ventilation into rooms affected. One source of moisture which is controllable is the ceasing of drying clothes on radiators with the home.

Rising damp 

Rising damp is seen in the form of wet walls near ground level where floors and walls absorb water from the ground and there isn’t a control measure in place to stop the water from rising.

Newer homes are built with a damp proof course installed 150mm from the ground level and is embedded into the wall to stop and damp from entering the homes.

Older homes, typically built with solid walls however won’t have a damp proof course installed and can lead to water ingress.

Once the damp has set in, it will leave to the damage of interior decoration like peeling wall paper and white powdery salt deposits forming on the walls.

If you are suffering from rising damp the remedies may be beyond the skill set of a DIYer and advise from a specialist damp proofing company should be sought

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