Defects - Roofs

Question 1

What are common defects typically associated with flat roofs?

Answer 1

Crazing
Ponding
Thermal Movement
Blistering
Flashing Defects
Perforation
UV Degradation

Question 2

How can you identify the extent of leaks in a flat roof?

Answer 2

A visual inspection may be sufficient, but where it is not, an electronic leak detection test or a thermographic examination could be undertaken.

Question 3

What is cut-edge corrosion?

Answer 3

Cut edge corrosion occurs at the edges of sheet panels which are cut to size. When cut, the coating is compromised and allows moisture in, which causes corrosion.

Question 4

What is the remedy for cut-edge corrosion?

Answer 4

Where cut-edge corrosion is identified, it must be noted whether the corrosion has reached the fixings or not. Where it has not reached the fixings, the affected part can be removed and either replaced or treated.

If the corrosion has reached the fixings, then the whole panel will need replacing.

Question 5

What is nail fatigue?

Answer 5

Nail fatigue occurs when a nail loses its strength, commonly due to corrosion, and the elements it is fixing together become separated. This is commonly the case with roof tiles.

Remedy may require simply using new nails, however it is likely that were one nail fails, the surrounding nails will also be susceptible to failure.