Cavity Wall Inspection Camera: A UK Surveyor's Guide

Agree the invasive inspection in writing

RICS Built Environment Journal describes a borescope as specialist equipment that can be inserted through a small drilled hole to examine cavity fill or wall ties. It also calls the technique a destructive test, so the nature and scope should be agreed with the client before proceeding.

Define the elevations or rooms, proposed access points, making-good responsibility, exclusions and the question the inspection is meant to answer. Confirm that drilling location and service checks are being handled by a competent person. If permission or a safe route is uncertain, do not make the opening.

Capture images that belong in a report

1. Photograph the elevation or room and mark the access point before drilling.
2. Create a file prefix such as “north-elevation_AP03”.
3. Record an orientation frame at the opening, then advance in measured stages.
4. Use the forward lens for depth and the side lens for the nearby leaf, tie or insulation edge.
5. Keep original files and put selected copies into the report with location, direction and limitation.

The current SanyipBores unit records to MicroSD and offers forward and side views without rotating the full cable. That supports a one-hole workflow, but it does not guarantee that a particular tie or damp path will fall within view.

Interpretation belongs beside other evidence

A still can show visible debris, a gap in insulation, surface staining or a corroded-looking component. It cannot establish the full extent, cause or structural significance by itself. Relate it to construction, exposure, moisture readings, thermal patterns and the agreed inspection question.

Use observational wording: “brown surface corrosion visible on the tie at AP03” is stronger than “all wall ties have failed”. State the number and position of access points so a client understands the sample size.

Tool-fit limits for a building survey

The probe is listed at 8.0 mm, while the cable is 5 m and semi-rigid. The access opening, cavity width, mortar debris and insulation can still block movement. The head is not articulating, and a side view is not the same as steering.

Keep the display dry; IP67 is published for the probe only. Withdraw if the sheath could snag, if resistance increases or if a hidden service risk cannot be excluded. A failed access attempt should be recorded as a limitation, not concealed.

Frequently asked questions