Leaky flat roofs seem to cause problems as the seasonal deluge of rain finds its way through small splits in roof membranes and into the building interior.
Water ingress is an annoyance as it is not always obvious where the point of entry is; water has a tendency to track its way through cavities, running along other services, and exiting at the lowest point typically where there is an intersection. The wind at this time of year exacerbates the problem, forcing water in some cases uphill and over, or through barriers which would normally be sufficient to prevent the water from entering the building.
There can be many factors synonymous to each building, which can be either caused by freak weather events or simply the barrier has failed and requires repair to prevent further water ingress. It can take many months to prove whether the repair has been successful as it can take time to simulate the same conditions and for the water to dry out.
We have been involved in a number of roofing projects recently at Derriford Hospital and Plymouth Science Park relocating outdoor air conditioning units to facilitate the roofing repair works. Traditionally concrete paving slabs have been used to mount these air conditioning units onto the roof; however these have quite sharp edges which during the course of time can embed themselves into the roof membrane under the weight of the units and slabs. This in turn can cause the membrane to split. If there is no option but to mount the units on the roof; rubber, composite, ‘Fix-It-Feet’ are a much better alternative to concrete slabs. If there are a number of units then a support framework can be used like the BigFoot or Roofpro modular frame systems.
Here is an example of Bigfoot frames, as listed on the Big Foot Systems website.
In the case of Plymouth Science Park, the decision was taken to remove the units from the roof material and elevate them to the wall directly above. This would solve two problems, the first to allow the roofing contractors access to the whole area to identify where the water had penetrated the membrane and the second would be to prevent this happening again.
Our engineers have spent a week on site at Plymouth Science Park elevating the seven outdoor air conditioning units, lucky for us the weather was decent, our client was delighted our quick turnaround and the end result.
Below are some of the before and after photgraphs from Plymouth Science Park: