Prior to the purchase of the property our Chartered Surveyor/Valuer may recommend that a wall tie assessment is completed if the property is of cavity wall construction and built prior to 1982. Wall ties are an important structural element to the building and are vulnerable to corrosion in certain circumstances. If wall ties fail, this can result in distortion or complete failure in the outer leaf of the cavity wall and the result of their failure is not normally covered by your buildings insurance. Prior to your purchase of the property, a Boroscope inspection can be completed which involves drilling a number of small holes in the external leaf of wall and inserting a Boroscope to view the existing wall ties.

 

A report would then be compiled that would include observations of the condition of the mortar, substrate in general, obvious defects that present visually, wall tie type and density together with the condition of any wall ties observed. Advice will also be given regarding future inspections necessary and whether or not replacement is required. We have our own copies of BRE (Building Research Establishment) Digests 329/401 as well as IP12/90 and IP13/90 so that our analysis can be as objective as possible.

 

Please note that a Boroscope inspection is only possible with the vendors’ express permission and that if the cavities have been filled with insulation (CWI) then a Boroscope inspection is unlikely to be successful. If CWI is present, a “semi-destructive” inspection can be completed which would involve the location of the existing wall ties and careful removal of the mortar beds around the wall tie ends to enable the assessment to take place.

 

Once this information had been gathered the mortar beds would then be made good using a sympathetic and appropriate mortar to ensure low impact inspection. We are happy to discuss these issues with the vendors directly prior to any inspection.

 

Most vendors are happy to grant permission for these inspections once they have discussed the matter with us. We are of course happy to let them view the inspection process to control permission actively during the survey.