Table of Contents
How far apart should wall ties be?
Wall tie spacing and positioning The maximum horizontal spacing is 900mm and the maximum vertical spacing is 450mm, although this may be varied if required by the Building Regulations. The ties should be evenly distributed over the wall area, in a staggered pattern, except around openings.
How often do you need a wall tie?
You need two and a half wall ties per square metre of masonry. The maximum horizontal spacing is 900mm and the maximum vertical spacing is 450mm. That’s why cavity wall insulation boards usually have a maximum dimension on the short edge of 450mm.
What is the British standard for wall tie design?
BS 5268 provides recommendations for wall ties for timber framed buildings. Information is provided for the type of structure, location, embedment, density and positioning. These ties are classified as Types 5 to 7; minimum declared values in tension and compression are listed for Types 5 and 6.
What are the signs of wall tie failure?
Horizontal Cracks in Brick Mortar Cracks along the masonry and brick mortar are tell-tale signs that wall ties have deteriorated and started to rust. As the tie rusts, the volume of rust expands inside the mortar where it sits. Over time, widespread buildup of rust can actually crack the mortar between bricks.
What are remedial wall ties?
Remedial wall ties are most often used for reconnecting the inner and outer walls of an existing cavity-wall structure. Wall tie replacement is often required when the original tying system loses strength as a result of corrosion.
How long do wall ties last?
In houses built before the 1980s, you can expect the wall ties to last around 15 to 20 years. For properties built since the 1980s, wall ties are generally made of stainless steel and can last over 50 years. And the most modern neoprene wall ties can last even longer than that.
Can I replace wall ties myself?
Typically, you can leave in place any original wire-type or ‘butterfly’ wall ties, embedded in standard-sized mortar joints. Generally, the metal is of insufficient mass for any corrosion to cause structural damage to the walls. Merely installing a replacement wall tie system will restore stability.
What is the purpose of wall ties?
Wall ties, sometimes called ‘brick ties’, are used in buildings with cavity walls. They are used to join the two leaves of a cavity wall together, allowing the two parts to act as a homogeneous unit. Hidden from view after construction, wall ties play a vital role in ensuring the stability of a building.
What is the minimum spacing for wall ties?
The minimum spacing for wall ties is 2.5 per m2. This is normally achieved by installing at 450mm centre spacing vertically x 900mm horizontally (6 courses x 4 bricks). These are staggered each row to produce a diamond pattern.
Remedial wall ties may be retrofitted to buildings built in different eras and to earlier building standards, and comprise materials or construction methods that do not comply with the current standards. Specific engineering design will be needed when performance comparable with current standards is required.
How do I fit helical wall ties to an existing cavity wall?
Competing helical wall tie systems require multi-part installation adaptors to fit the ties into existing cavity walls. Such lengthy adaptors work with a telescopic action and can be expensive, unreliable, and cumbersome to use.
How do you fix a broken tie on a brick wall?
The tie is then driven in, using a hammer drill and a product specific driver that will slightly recess the tie below the surface. The resulting small hole is then pointed over with matching mortar, making the repair nearly invisible. The advantage of this type of remedial anchor is that they are quick to install and are relatively inexpensive.