Damp test

A damp test is a moisture-meter reading of the walls, roof, floor, and bottom corners of a motorhome or caravan habitation area. It is the core element of a habitation check and reveals hidden water ingress long before it rots the timber frame or delaminates sandwich panels.

Readings: under 15 % is healthy; 15–20 % is watch-and-recheck in six months; 20–25 % means seals need re-doing; over 25 % is serious water ingress with likely structural damage. The UK CRiS scheme and European builders classify zones as A/B/C risk. Trouble spots: lower corners near wheel arches, window frames, perimeter roof seams, and the surrounds of roof lights. Most manufacturers maintain their water-ingress warranty only with an annual damp test on record.