Endoscope inspection within a cavity wall

Cavity walls are constructed with metal ties linking the external and inner leaves to maintain structural stability. Ties have been mainly made from steel over many years. Some old buildings have untreated steel ties which corrode. This may break the structural link between the two leaves. Additionally, corroding steel expands to approximately nine times its original volume. Expansion of steel ties within brickwork may cause structural movement and damage.

Later buildings were constructed with galvanised steel ties which, initially, do not corrode but corrosion eventually takes place. Since 1981 buildings should have been constructed with stainless steel ties where corrosion is virtually non-existent.

Our endoscope operates through a small hole drilled through a mortar joint within the external leaf brickwork enabling us to view the interior via a miniature camera and take photographs.

Additionally, the endoscope inspection will reveal the existence of cavity wall insulation. Many purchasers are particularly concerned about energy use and heat loss. We are able to report that cavity walls either require insulation or have been insulated in the past.

Endoscope inspection beneath parts of some timber floors

One of the areas of difficulty when inspecting older property is the condition of concealed timbers beneath floors. It is not possible to inspect most sub-floor areas. Surveyors are able to obtain much information by testing floors for dampness, checking for stability/past movement, checking ventilation beneath floor structures and testing for dampness in adjacent locations. It is sometimes possible to lift a floorboard and inspect beneath, assuming that other parts of the floor are in similar condition. It is most commonly not possible to lift a floorboard without damaging floor finishes and vendors often refuse permission for invasive inspections.

Our inspection with a miniature camera/endoscope provides additional information so that we may report more fully on the condition of the floors. An inspection in one location is made and it is assumed that conditions will be similar elsewhere.

Ceiling sag in historic buildings can be investigated with the fibre optic endoscope – here remedial works may lead to suspension of the debonded area by straps above supported by the ceiling joists.