Is it Time to Replace Your Vent Pipe Flashing?

Is it Time to Replace Your Vent Pipe Flashing

As part of my day job, I review roof reports frequently. A common defect is the failure of vent pipe flashing, allowing water through the roof.

The weathering and gradual deterioration of the Dektite or rubber boot is often a widespread cause for roof leaks. If you’ve noticed ceiling damage from rainwater, chances are it’s the stink pipe flashing.

What is a stink pipe?

Every house will have a sewer vent pipe penetrating through the roof. It’s sometimes referred to as a ‘stink pipe‘ due to the odours it releases. The vent emits sewer gases to prevent them building up in the home and to balance the air pressure in the sewerage system.

Where is the vent pipe located in my home?

Your vent pipe, is usually located near the bathroom or toilet of the home. The pipe penetration has a pointed end shaped like an airplane nose. The penetration through the roof sheeting requires flashing to ensure water doesn’t seep around the roof opening at the base of the vent when it rains.

Dektite is a popular flashing used to keep the penetration watertight, but like all materials exposed to the sun and weather elements, it can deteriorate and require replacing.

new dektite flashing

When should you check your vent pipe flashing?

If you live in a single storey house with a pitched roof, you can do a visual inspection from the ground to see if your vent pipe flashing looks deteriorated.

A tell-tale sign is if you have water damage to your ceiling. This indicates the water has made its way under or through the flashing.

A yearly check can keep your roof water-tight

A visual inspection of our vent pipe showed it was overdue for replacement. Our home is 17 years old. The rain this year has caused the paint to swell on the toilet ceiling which was located directly under the vent pipe.

vent pipe flashing badly deteriorated
Terribly deteriorated vent pipe flashing

When the original rubber boot flashing was removed, the rubber was cracked. A new Dektite was purchased from Bunnings and it was sealed to the roof.

old vent pipe flashing cracked

Who should replace flashing on your roof?

Roofing is a specialist trade. Ideally, your roof should be inspected yearly by a licensed roof plumber, including the flashings around roof penetrations. Unfortunately, these inspections don’t occur until water stains appear on the ceiling which indicates a roof leak.

Keeping your roof water-tight is a homeowner’s responsibility and is a condition of home insurance.

replaced dektite roof flashing

Roof work, including replacing flashings, should be done by a licensed roof plumber. Safety is paramount when inspecting and repairing roofs. A homeowner may be able to do a perimeter inspection around a single storey house, but for a double storey property, it’s best left to engage with a licensed roof plumber.

Other Roof Articles