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DAMP PROOFING CONTRACTORS FOR TREATMENT OF RISING DAMP, WOODWORM, DRY ROT AND BASEMENT TANKING SPECIALISTS THROUGHOUT THE NORTH EAST

Tyne & Wear (Newcastle, Sunderland, Durham, South Shields, Whitley Bay)

Tyne & Wear (Newcastle, Sunderland, Durham, South Shields, Whitley Bay)

Northumberland (Ashington, Bedlington, Blyth, Cramlington, Morpeth)

Northumberland (Corbridge & Hexham)

Northumberland (Alnwick)

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Wall Ties

Wall ties literally provide stability to the structure of your building. When originally installed, the bricklayers would have probably used mild steel wall ties. These can fail catastrophically and leave your walls unsafe and even lead to collapse.

Wall Tie Replacement Guide

Important

If wall ties need replacing, the work needs to be done properly, as it is restoring the structural integrity of your house. To help you understand the process better, Tyne Tees Damp Proofing has created a handy guide to help.

1: Cavity Wall Tie Replacement

For over a hundred years UK property walls have been constructed with brick and stone incorporating a cavity or void between the courses, Steel ties have been manufactured to link the leaves of the walls. These are known as wall ties, cavity ties or brick ties, they connect the two walls, helping them perform as a solid wall. The reason for creating a cavity is to reduce damp, reduce heat loss, and reduce the carriage of noise.

Wall ties secure the outer wall with the inner structure, they balance tension and compression loads, allow for movement between the walls and maintain function in the event of a fire. As you can now see, wall ties are a very important part of your building.

Fish Tail Wall Tie
Fish Tail Wall Tie

Wall ties, started with plain unprotected, stamped out mild steel plates with a ‘fish tail’ profile formed on the ends. These ties often rust/corrode with the moisture (particularly in the outer leaf). This corrosion can cause the mortar courses to separate leaving horizontal cracks in the wall. With the advance of technology wall ties changed in shape and have often been treated with a protective layer of zinc or bitumen. This was used in house construction right up to the early 1980’s. These treated ties were better than untreated ones but were still fallible often losing the surface protection when being carted around building sites, a simple scratch could allow rust to form on the ties which could lead to them snapping in the cavity. The majority of modern wall ties are made from stainless steel, which drastically increases lifespan and reduces thermal conductivity.

When do you need to replace wall ties?

Wall ties will need to be replaced if they corrode or fail. Wall tie failure may be due to many things.

  1. Poor construction, corrosion, insufficient quantities, badly positioned ties, etc.
  2. Mild steel ties deteriorate and become rusty with age. Chemical reactions can occur between iron in the steel and moisture, causing the wall ties to fail.


Regardless of the cause of cavity wall tie failure, wall tie replacement will re-secure the main structure of the building. This will create stability between the leaves of the structure once more, distributing the loadings correctly once again.

2: Symptoms of Wall Tie Failure

The most common warning signs to look out for are:

  1. Horizontal cracking at regular intervals – this is often a sign of advanced wall tie corrosion.
  2. Bowing out of walls or uneven faces of walls can indicate that the outer wall has disconnected from the internal wall and may be no longer supporting the main structure of the building


Rust can cause steel ties to expand to several times the thickness of the original steel. This expansion is powerful and can cause the bricks above to lift and leave noticeable horizontal cracks to the wall.

These cracks usually appear at the upper level of the walls where the weight of the brickwork is less. The cracks usually occur along several mortar bed joints incorporating the corroding wall ties; ties are usually set in courses around six bricks apart.

Wall Tie Failure - Horizontal Cracking In Brick Work
Wall Tie Failure - Horizontal Cracking In Brick Work
Wall Tie Failure - Horizontal Cracking In Brick Work
Wall Tie Failure - Horizontal Cracking In Brick Work

3: Wall Tie Corrosion Survey

Here at Tyne Tees Damp Proofing we have experienced specialist surveyors who will be able to confirm if there is a problem with the wall ties, a series of checks and tests will reveal the condition and integrity of the wall ties.

If in doubt, get the experts out!

Replacing defective wall ties

  1. Our technicians will locate the position of existing ties using a wall tie detector. They will mark the position of the existing wall ties for removal after the replacement ties have been replaced.
  2. A borescope can be used to see the condition of the wall ties in the cavity, however this is not always possible, for example – if there is cavity wall insulation present.
  3. Exposing the mortar at the tie-ends can allow the inspection of a section of the steel most vulnerable to corrosion, this will confirm the type of tie and the depth.