Establishing the Build Up and Condition

Carrying out core sampling provides information on the material construction of the roof waterproofing, insulation incorporated and deck type whilst also providing evidence where water ingress may have occurred. Core samples are taken at strategic locations on the roof to increase the chance of establishing the exact build up, whether there is tapered insulation present, to find entrapped water in the system and to establish consistency of the build-up on the entire roof area. This usually includes multiple core samples.

Core Sample Analysis

Although water ingress usually accumulates at the low points on a flat roof, it can also be found on the other areas, for example, when an existing roof area is found to contain tapered insulation, then the falls that are visible on the surface of the waterproofing are different to the falls under the tapered boards. This can lead to water accumulation in unexpected locations. Our trained technical mangers will give guidance on this during the survey.

Photographic records of each core sample are taken and used within the finished report for visual evidence and clarification of the located.



The process for the sample taking is:

• The locations to be sampled are identified. Samples will be taken at high and low points of the roof area.
• Each core sample is taken by removing an area of the waterproofing, typically 10x10cm to reveal the layers of the build-up down to the deck.
• Roof layers are recorded for the report and the deck type noted, along other noticeable conditions.
• The presence of any water within the roof layers is detailed and photographed, and the moisture levels within the insulation measured with a moisture meter.
• Once the build-up has been photographed and recorded the materials are repositioned and covered with a self-adhesive, liquid applied or heat applied patch to fully seal the trial space.