Specialist External Wall Insulation Installers in Ipswich, Suffolk and Colchester, Essex

External Wall Insulation (EWI) is an extremely effective means of insulating solid wall properties to significantly reduce the amount of heat lost through the walls.

The installation process involves fixing a layer of insulation material to the external walls of a property, and covering it with reinforcement and a special render in a range of decorative finishes.

Cornerstone was originally established as an EWI specialist in 2004 and has externally insulated thousands of domestic properties all over the UK, both for private owner occupiers and landlords, as well as on behalf of local authorities and housing associations.


Uninsulated solid walls can leak up to 45% of a property’s heat – insulating these walls can save up to £425 per year on your energy bills.* Solid walls can be insulated externally or internally, with the cost depending on the property size and type. External Wall Insulation (EWI) offers a number of benefits:

  • Creates a warmer and more comfortable home
  • Significantly lowers your energy bills
  • Improves the appearance of your property
  • Reduces external property maintenance
  • Prevents condensation and mould growth
  • Increases the value of your property
  • Increases sound-proofing of your property
  • A 25 year insurance backed guarantee

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If your home was built before 1920, it will most likely have solid external walls with no cavity. The lack of a cavity means more heat can escape from your house through the walls.

External wall insulation is applied to the external face of the wall and can often be the single biggest home improvement you can make to reduce heat loss.  The insulation makes it much more difficult for the heat to pass through your walls, keeping as much of it as possible inside your home for as long as possible.

You should be able to tell which wall type you have by looking at the brickwork on the outside of your house. If your home has solid walls, you will be able to see a pattern showing the long and short side of the bricks like Fig A.

If your home has cavity walls, you will only be able to see the long side of the bricks like Fig B.

It is suitable for the majority of properties, including those of non-traditional construction, but not for listed buildings or those located in a conservation area.  If that is the case for your home, you may be able to consider internal wall insulation as an alternative.  Generally, planning permission will not be required if the finish will be similar to the existing property exterior, although your local planning department will be able to confirm this.

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External Wall Insulation

Ipswich, Suffolk

Colchester, Essex

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01473 561 031

What is damp?

Damp is a common problem, that properties across the UK will suffer from at some stage. If untreated, damp can be extremely damaging to the structure and fabric of your home.

If you are unsure what causes structural dampness, it is the presence of unwanted moisture in the structure of a building. Dampness is caused by either the result of penetration from outside or damp created within the property.

Why does damp occur?

A high proportion of damp problems in buildings is caused by penetrating damp and rising damp. In most cases, dampness is caused by defects or damage to a building like defective roof coverings, render or rainwater gutters and downpipes.

Where can dampness be found?

Dampness can be found anywhere in a building and can affect all types of properties, old and new. It is important that when dampness is suspected you get an accurate diagnosis to determine the type of damp and the cause of the problem. 

How can I identify dampness?

At Damp Proofing Specialists, we use a wide range of instruments and techniques in conjunction with our experience to investigate and identify the presence of excessive moisture in buildings. It is important that a professional surveyor assesses your property to determine what is causing the damp.

Is my property damp proof?

It is vital that your property has a damp proofed structure that will protect the building from problems such as penetrating damp, rising damp and below ground damp.

A Damp Proofing system is a moisture control barrier that can be applied to walls, floors and the structure to prevent moisture from passing into the interior living spaces. Damp issues in buildings is extremely common in the UK and damp remedial treatment is one of the most common property care repairs.

What is damp proofing membrane?

The ground below your floor should have a damp-proof membrane to stop damp coming from the ground and a damp-proof membrane can be applied to the internal side of an external wall to stop damp getting to your plaster and decoration. These membranes are also used on wall areas that are below ground level that can be affected by penetrating damp from the ground.

Why remove plaster during damp proofing?

Plaster must be removed during the damp proofing process as rising damp coming from the ground not only brings moisture but also brings hygroscopic salts, nitrates, and chlorides.

Hygroscopic salts attract moisture from the atmosphere. These salts will contaminate the plaster inside the property and even after a remedial DPC has been inserted the salt contaminated plaster can still become damp. It is vital that contaminated plaster is stripped and replaced during the treatment.