Structural Damage

Cavity Wall Tie Repair

Cavity walls have been a common feature of buildings in the UK for over one hundred years. Two leaves of brick or stonework are held together using metal straps or "wall ties". The cavities between the two leaves of masonry provide an affective barrier to water penetration and also acts as an insulation layer.

In some circumstances these wall ties can corrode or fail. Failure can manifest itself as cracking in the external leaf of masonry, structural movement or in severe cases the collapse of sections of masonry.

To combat this problem, repair strategies have been developed. These usually involve the installation of new remedial wall ties through the outside leaf of masonry into the internal leaf. The original wall ties are then removed or isolated from the structure to prevent further damage to the structure. In some special circumstances it may be possible to leave the existing ties in place.

Structural Restraint

This definition covers a great number of structural repair techniques that can be utilised to repair or restrain masonry walls. Unwanted movement can occur in buildings for a great many reasons, these may include.

• Ground movement or subsidence
• Inadequately restrained or tied walls
• Movement brought on by water ingress and timber decay into the structure
• Failed lintels or building materials
• Movement fatigue
• Mechanical impact or disturbance

In all these examples a structural surveyor may recommend some form of mechanical restraint as part of the remedial repair.

The repair techniques that can be adopted may include the use of

• Structural wall ties and restraints
• Embedded wall stitching
• Strapping
• Structural Pinning
• Resin bonding or resin beam repairs

These types of structural repairs should always be specified and supervised by a trained and competent structural engineer and any installations must be undertaken by an experienced specialist contractor. Experienced specialist contractors can be found amongst the members of the Property Care Association.