Trusted Expertise in Wall Ties & Restraint Fixings

Colne Valley Preservations’ specialist surveyor is experienced in diagnosing wall tie failure and can recommend the best approach to rectifying the situation. Remedial wall ties can be installed by our expert technicians. These ties are made from a high grade material that will not corrode or rust, meaning the wall will be left stable and secure for many years to come. Cosmetic repairs can be made to ensure that that appearance of the wall is not altered due to the installation of remedial ties.

Wall Tie Replacement

Wall ties are an essential element for the stability of a cavity wall structure, tying its weather protecting brick facade to the main body of a building. An effective brick tie system transfers static and live loads across the cavity, enabling load sharing by both inner and outer walls. Typically cavity wall ties are bedded in a mortar bed joint as a building is constructed.

Cavity wall tie failure can be a consequence of a construction defect; for example where the original ‘built in’ cavity wall ties have been omitted, incorrectly fixed or fitted with brick ties that are too short. Alternatively failure may be a result of a buildings aging process, whereby wall tie corrosion may have compromised the walls load sharing capabilities.

Over time mortar joints, which host the wall ties, undergo a chemical change through carbonation. The mortar becomes aggressive to the steel base and its protective coatings, reducing the life expectancy of the cavity tie systems to as little as 26 years. the design life of the building is typically much longer than this period and it therefore follows that at some point a remedial retrofit replacement of the brick ties may be necessary if the stability and load sharing capacity of the wall is to be maintained.

As wall tie corrosion sets in, the mild steel brick ties generate a build up of iron oxide layers which occupy a greater volume than that of non-corroded steel. In most cases, particularly when wire wall ties have been used, the increase in the volume is accommodated in the mortar bed as the cavity ties corrode. In such cases there may be little sign that the outer facade is free standing and the walls not supported, save the wall may appear bulged.

In other case, particularly when sheet steel or vertical twist ties have been used in less forgiving mortars, the iron oxide build up may have the effect of lifting the masonry above a line of insitu brick ties. If expansion is widespread and present along several rows of corroding cavity wall ties, a tell-tale pattern of horizontal cracks may be produced along each wall tie course.

Lateral Restraints

Lateral restraints are wall ties used for restraining bulging walls.

Lateral restraints are fitted from outside the property with a minimum of disturbance – in most cases just lift a few floorboards to determine the position of the joists and to ensure wires or pipes that may be hidden are avoided during tie installation.

Each of our Lateral restraints wall ties have a drill like leading end for cutting into softwood. Using a drill, simply wind the lateral restraint ties into the timbers and resin fix the masonry end.

Crack Repair

Crack stitching bars are heavy duty helical bars (8kN+) and are ideal for the masonry repair of wall cracks where shear strength is an issue. This 6mm diameter wall crack stitching reinforcement offers extra performance to other helical bar type products by significantly increasing the shear, tensile and flexural strength of cracked masonry walls.

The hi-fin design on our Crack Stitching also makes the Thor Helical Remedial Crack Stitching products ideal for grouting into mortar beds to retrospectively reinforce distressed masonry and to control cracking by distributing forces back into the structure. The various Thor Helical Remedial sections are directly proportionate to one another, providing opportunity for cross correlation of performance characteristics to be used in specification design.

About us

Colne Valley Preservations is a family business based in Nelson, Lancashire. We have successfully been established since 1981 with over 40 years experience in Remedial Treatments of Damp Control, Damp proofing, Rising Damp, Penetrating Damp, Lateral Damp, Condensation and Mould Control, Timber Preservation, Wood Infestation, Dry Rot, Wet Rot, Woodworm, Timber Treatment, Structural Waterproofing, Basement Waterproofing, Cellar Tanking, Wall Tie Replacement, Lateral Restraints, Crack Stitching.

We also do Electro Osmosis Damp Proof Courses, DPC Chemical Injection Damp Proof Courses, DPC and Re-Plastering in line with trade body specifications.