The recommendations for installing roof-mounted plant and M&E equipment on a single ply flat roof vary depending on the size of the equipment and the way it needs to be supported. In selecting an appropriate solution, consideration should be given to future access to the membrane beneath the plant for remedial works and inspections, without the need to decommission the equipment.

Large items of plant should be mounted on a steel frame, supported on stub columns that penetrate the single ply flat roofing system. The columns should be circular or square section to make waterproofing them as easy as possible. Cowls should be fitted at least 150mm above the finished roof level to provide full waterproofing protection to the detail.

Smaller items can be mounted on paving slabs with a sacrificial layer of membrane beneath them to protect the primary waterproofing layer, or specifically designed plant support systems. Any rubber feet should have a separating membrane/layer between the base of the foot and the waterproofing membrane to avoid any chemical compatibility issues. Consideration to the loading applied on to the roof system should be taken in to account to avoid crushing of thermal insulation or waterproof covering.

Cables and pipes that need to return into the building through the roof system should be routed through a swan neck pipe detail, finished in accordance with the manufacturer’s standard detail. If cables and pipes need to penetrate an upstand, the penetration should occur a minimum of 150mm above the finished roof level to allow for waterproofing with an appropriate cowl. Contact the IKO Polymeric technical services team for advice on correct detailing for your project.

For more information, please contact IKO Polymeric’s technical team.