Intrusive Flat Roof Surveys – What to Expect

Last week we took a look at intrusive flat roof surveys and when they should be used.  With so many commercial and industrial premises in the UK featuring a flat roof, there is often plant or machinery installed on flat roofs which means that regular roof access for repairs and maintenance is a must.  One of the best ways to ensure the safety of personnel accessing a flat roof is to provide a demarcation barrier system to ensure that the route to plant and machinery is safe.  It’s also the case that domestic extensions will often be completed with a flat roof, so today, we’re going to take a look at what you can expect in an intrusive flat roof survey.

Firstly, you’ll need to make sure that a fully qualified professional carries out the flat roof survey.  The initial step will be to carry out a risk assessment – this will be done by the contractor you hire who is responsible for providing safe access to the roof.

After a thorough examination, the contractor will determine whether an intrusive survey is necessary and which part of the roof to use for this purpose.  If an intrusive survey is considered necessary, then core samples of the roof will be taken.  This involves cutting out a small section of the roof to expose the different layers back to the deck.  However, an intrusive survey of this type should not be carried out if the roof is still under warranty as this may render the warranty invalid.

The core samples will be taken from several areas across your flat roof to allow comprehensive inspection of the roof build up and condition.  The core samples taken are able to:

• Identify the roof build up and the type of deck installed
• Gain insight into the current condition of the materials and identify which (if any) need replacing
• Test for moisture in the roof, thereby identifying leaks and any potential interstitial condensation – this is where moisture vapour condenses inside the fabric of the roof and leaks back into the building.

Several core samples will be taken from your roof in areas which, in the contractor’s experience, will give a good idea of the condition of the roof as a whole structure.  For example, core samples will be taken at the highest and lowest points of the roof to determine if the installation in use is flat or tapered. 

Core samples are cut avoiding any potential ponding areas, or areas which appear to contain damaged or weakened materials.  The core sample areas are then sealed effectively to ensure that your roof is returned to its pre-survey condition.

Following the survey, you will be provided with a detailed report that will enable you to make an informed decision on your flat roof in future.