Damp diagnosis case studies This information is only available to paying isurv subscribers. Stage 1, 2 and 3 Damp zone survey duration: 90 minutes. Property details... To continue reading, start your free trial here. Please note your trial does not include access to downloads. To explore our subscription options and access downloads, please click here. Or sign up to the isurv newsletter, your monthly round up of the latest isurv updates. For further questions, don't hesitate to call: +44(0)247 686 8555.