A wall tie is a steel bar or strap which is built into a cavity wall to hold the masonry together; usually made of mild steel. Wall ties are crucial to the stability of external walls.

Older ties were made of a thick mild steel bar formed into the shape of a fishtail.

More modern ties are made of a twisted wire and form the shape of a butterfly.

Any building with cavity walls built prior to 1981, an estimated 10 million dwellings, could be prone to wall tie corrosion and failure.

If the steel of a wall tie is exposed to air and oxygen, the all too familiar rusting cycle begins. The loss, by rusting and corrosion, of the wall tie is one problem but the other major consideration is the increased volume of the steel, causing mortar to split and lift. This will result in instability of the cavity wall and the likelihood of it moving out of plumb.

Wall Tie Corrosion and Failure

The failure of your wall ties could cause the eventual collapse of an effected wall, the remedial work required to repair a wall is time consuming and expensive.

If wall tie corrosion can be identified at an early stage then modern techniques can stabilise cavity walls at a fraction of the cost of re-building. BAR Preservation are experts in the latest remedial wall tie repair and replacement with corrosion resistant stainless steel ties.

Are Wall Ties only used in Cavity Walls?

Wall ties should always be used in cavity walls but they should also be used in solid brick walls when the walls are constructed with no brick bond between the inner and outer leaves such as nine inch stretcher bond.

What is Cavity Wall tie Corrosion?

Wall tie corrosion is the term used when the metal ties which bond the inner and outer leaves of masonry or brickwork together corrode or rust due to lack of protection or the breakdown of the original protective layer.

The wall ties used around the 1930’s were not always galvanised but were usually coated with a thin layer of pitch, in later years a thin galvanised layer was added to ties.

Ties like this were installed up until 1981when the British standard changed and the thickness of the galvanised layer required for ties was increased. Currently only stainless steel wall ties are recommended.

What is Cavity Wall Tie Failure?

Wall tie failure happens when the existing ties corrode, reducing the structural strength or completely corroding away and breaking.

Many houses were built with an insufficient number of ties so when the ties on these properties start to corrode, building collapse can happen long before the ties are completely corroded through.

How can I tell if my property has Cavity Wall Tie Corrosion?

There are some ‘tell tale’ signs of wall tie corrosion or failure; look out for:

• Horizontal cracking in walls; this is often due to the expansion of corroding ties and usually starts at a high level.
• Bulging walls; caused by the failure of existing wall ties.
• Lifting of walls just below roof level; caused by the expansion of the wall ties in several courses of brickwork.

Replacement of Wall Ties

At BAR Preservation we have fully trained experienced technicians who can carry out any remedial structural works specified by our surveyors or by your own independent structural engineers.

BAR Preservation has carried out wall tie replacement works to thousands of properties for domestic clients, councils, housing associations, English Heritage and many more.

BAR Preservation are full members of The Wall Tie Installers and the Property Care Association and offer full Independent insurance backing to our twenty five year Guarantees.