How To Find A Leak In A Metal Roof

Table of Contents

1. Common causes of roof leaks
2. Misaligned screws
3. Stack flashings
4. Curb flashings
5. Improperly sealed seams and overlaps
6. Signs your metal roof is leaking
7. Surface corrosion
8. Excessive movement
9. Missing fasteners
10. Damaged panels
11. What to do if your roof is leaking?

Metal roofing screws hold the panel in place and compress a rubber gasket underneath thereby creating a watertight seal. Misaligned or loose screws allow water to run between the panel and the gasket. This type of leak can cause damp spots on ceilings. 

Stack flashings are used to seal around vents or pipes that come out of the top of the roof. Stack flashings are made from rubber which can deteriorate in the sun. Once the rubber becomes brittle it breaks off causing water to run behind the panel.

Curb flashings are used to seal the edges of the roof. Improperly installed curb flashings will cause water to pool in the edges and joints. This will eventually weaken the sealant allowing water to leak inside causing damp ceilings and walls.

Metal roofs are designed to move, so it is vital that seams and overlaps are properly sealed using a special metal roof sealant. Sometimes roofing contractors use silicone which does not create a strong bond with the metal panels and deteriorates over time.

You may think it's obvious you have a leak because water will be streaming down the walls, but if your roof has reached this stage, it’s long past the point of repair. It’s much better to identify leaks before they cause long term damage.

Surface corrosion does not necessarily mean you have a leak, but excessive rust can compromise the roof's ability to shed water, so you should carefully monitor rust patches. Excessive corrosion can be prevented from spreading by applying a rust inhibitor.

Metal roofs are designed to move as the building expands and contracts, but any excessive movement is a sign that something is wrong. Metal roof panels should be securely fixed and not move when light pressure is applied.

Metal fasteners are used to secure the metal roof panels, plywood substrate and insulation to the roof structure. Missing fasteners will cause water to leak through the outer membrane causing damp patches on the ceiling.

Debris falling or even walking on metal roofs can cause the panels to become creased or dented. This puts excess strain on the fasteners and weakens the seams. Ultimately this will allow water to leak through the gaps causing dampness on walls and ceilings.

Most metal roof leaks can be repaired cost-effectively if they are identified early, so if you notice a leak, get your roof checked out by a qualified roofer. We don’t recommend doing this yourself - climbing on roofs is dangerous work, so leave it to the professionals.

Mid Richmond Plumber is one of the Northern Rivers' leading roofing contractors. Our experienced and qualified roofers provide roof repairs to metal roofs of all types and sizes. Get in touch to arrange a FREE inspection of your metal roof today by completing the contact form or calling us on (02) 6683 2281.