The Typical Cause of a Leaking Flat Roof
Why, oh why, do people design and build flat roofs when, for very little extra cost and effort, the roof could have been given a slight ‘fall’ to shed water efficiently and therefore avoid the all to common problem: a leaking flat roof.
It is a question that must occur to many thousands of people every year when they are faced with leaking flat roofs.
Traditionally, flat roofs were sheeted with roofing felt but other materials such as waterproof paint for flat roofs, combed asphalts, fibreglass (GRP), EPDM, PVC and Butyl coverings are also often used as a waterproofing membrane to weatherproof flat roofs.
What causes a flat roof to leak?
The causes of leaking flat roofs can be as a result of one or more of the following:-
- Cyclical Expansion and Contraction
- Movement within the components of the roof
- Thermal Shock
- Ponding of water in declivities
- Wind driven moisture ingress
- Ultra Violet degradation
- Loss of Elasticity within the Membrane
- Abrasion from foot – traffic
- Failure of seams, overlaps or upstands
- Uplift due to wind shear or intermural vortexes
- Damage to edge fillets and closures.
Any of the above may result in cracks, splits, blisters or loss of adhesion of the existing roof covering.