Roofs Flashcards
What are the common defects associated with flat roofs?
Crazing, Ponding, Thermal Movement, Blistering, Flashings and Falls Around Copings, Person damage, cracks adjacent to joists.
Name me some methods of assessing flat roofs for defects?
Electronic leak detection.
Thermal imaging.
How does electronic leak detection work?
A weak electrical field is created on the dampened surface and any current that ‘earths’ into the building changes the nature of the field locally. This should pinpoint the penetration or just as importantly show when water penetration is not caused by a roof leak.
- What are the remedial measures for flat roof defects?
I’ve attended a CPD session regarding a liquid applied membrane. The manufacturers recommend the roof covering is stripped, a base coat then new insulation is laid with a final cold applied top membrane. The use of grass-fibre reinforcement allows the system to be applied to upstands with no join in the membrane covering.
What should you take into account when deciding whether to repair or replace a flat roof?
Age, previous repairs, cost, when does it leak, is there ponding, what is below the roof, proportion of roof damaged.
