Can you or your builder undertake these works?
The short answer is yes, anyone can install remedial cavity wall ties and they are available to buy on the internet and in builders merchants.
But there are many reasons not to!
Why is it that structural engineers, architects, local authorities’ and mortgage lenders instruct you to employ a specialist to do these works?
Cavity wall ties are an integral and crucial to the stability of all cavity walls.
Before considering installing new remedial cavity wall ties, these points should be considered:
Corroding wall ties
Firstly, what type of tie should be installed, below are just a few examples as there are many to choose from dependent on the type of structure:
Neoprene mechanical ties
are installed where some flexibility is required, but there are a number of issues which can result in failure, if installed by unqualified contractors.
Dry fix ties
these type of ties are installed into a wall structure, where the substrate may be soft, and getting a fixing is not easy an alternative is the aron resin tie below.
Lateral restraints wall ties
which start from a meter long and are installed to restrain bowing walls, by fixing into other parts of the building other than the inner wall, which may not have the required strength, or stability.
Dust : drill dust acts as lubricant like talcum powder, and if the hole is not effectively cleaned that the tie will slip and is most common reason for this type of wall tie to fail.
Correct tooling and testing of the wall ties is required, and of course knowing how to use it.
What guarantee will be issued, covering the materials and the workmanship if you or an unqualified contractor undertake the works and is it a true independent insured guarantee, most lenders will only lend on a property if the works are covered by a credible insurance backed guarantee, can you provide one, or will you end up with a property you cannot sell.
Testing: Did you know that the wall ties system should be tested.
Look at the property within the photograph to the left, not the cracking to the horizontal mortar beds.
Also note the stepped cracking to the area between the first and ground floor windows. These are visual evidence of extensive wall tie failure, this is due to the corrosion of the installed wall ties, within the mortar beds, applying pressure to the brickwork as a result of the corrosion, steel expands approximately 10% of its volume when it corrodes.
What is the alternative if the installed remedial ties fail, due to these being installed incorrectly ?
Lack of suitable support for the wall. Further cracking and movement.The wall collapses or requires further support measures installing, like the one on the right, the wall was reconstructed by an unqualified builder. The property was later declared unsafe, due to movement of the inner wall and floors, with insufficient funds to undertake the required remedial works, and the contractor is nowhere to be found, the owners have had to move out. How to avoid this use a PCA registered contractor and have a survey undertaken by a qualified surveyor http://www.property-care.org/
If you have any questions please call us on 0161 633 9860 and we will be happy to answer any of your questions or make arrangements to undertaken an inspection, of your wall ties to ensure your property is structurally sound. http://olympic-construction.co.uk/