Flashing is an important part of keeping your roof waterproof and thereby weatherproofing your home. Flashing is both a physical barrier and a method to keep water from entering the roof and subsequently causing damage to your internal structure including your beams, ceiling, and walls. Flashing is a covering over the seams of your roof, including any section wherein your roof meets a vertical surface such as a chimney, valleys, skylights, or a section of roof with a different pitch. Roof flashing protects your roof from moisture as well as vermin and pests from entering and setting up shop on your roof. Weatherproof your home by installing and maintaining adequate flashing on your roof. There are many kinds of flashing including roof, chimney, and wall flashing, in this article, we will look specifically at roof flashing. Roof flashing is applied in any area of the roof where water would run off and the flashing provides a way to guide the run-off water away from the roof and into the gutters. The below image illustrates the anatomy of a roof and shows the areas of a roof that would require flashing including the valley, chimney, vent pipes, and around a skylight.
What is roof flashing?
It might sound foreign to you, but roof flashing is an additional important element of a roof that is secured to your roof and weatherproofs your home. Roof flashing is a thin material made of metal sheeting that is installed underneath your shingles to redirect water away from the joints, holes, and seams of your roof, protecting your roof from any unwanted moisture and subsequent deterioration. The sheets of flashing overlap with each other to create a protective barrier for your home in areas of your roof that are most vulnerable. Since the roof is installed on an angle for pitch and drainage purposes, it is vulnerable to water pooling in areas, making it an easy target for water penetration and trapping moisture in the crevices of your roof such as in your valleys. Areas like chimneys, skylights, and vents are areas where flashing needs to be installed to guide water to its proper drainage point. Flashing is available in a variety of materials, with galvanised steel being the most common in Australia. Copper is second in line in terms of the best materials historically for flashing, however, it is on the pricier side. Other materials on the market include lead (durable, but could be a health hazard through polluting the water that goes down your pipelines) and aluminium (very malleable, but needs an additional layer of coating because bare aluminium would not suffice). Because there are many variations in types and styles of roofing, there are also loads of flashing varieties that are available to suit every roof.
Types of Roof Flashing
- Base (for vulnerable areas like chimneys)
- Valley (for open valleys on your roof)
- Skylight (for glazed openings)
- Step (bent in 90 degrees, installed as layers)
- Drip Edges (edge of the roof)
- Counter (opposite of base flashing)
- Kickout (bridging the gap between the step and the gutter)
What does flashing do?
Imagine the shape of a valley. The purpose of the flashing on your roof is to prevent water from being trapped and pooling in the valleys, edges and corners on your roof. The pooling of water after heavy rain can lead to a multitude of problems. The ongoing exposure to moisture can lead to rust, but it could also pose a health hazard: a mosquito’s breeding ground as well as other creepy crawlies that could use that moist area for their inhabitation. If left unattended, this could also be the starting point of leaking on your roof and ceiling due to rust or rot as result of moisture penetrating the materials on your roof. If you don’t address this initial problem with your flashing, it could eventually lead to whole destruction of your roof.
What material is flashing made up of?
Roof flashings are available in a variety of materials and styles to choose from. Roof flashings are usually sourced from elements like copper, zinc, aluminium, lead, steel (galvanised and stainless), plastic and composite. Out of all the mentioned materials, most homes go for galvanised steel due to its durability, affordability, and anti-corrosive properties. For environments that are exposed to harsh conditions such as salt spray, steel is a front runner due to its resilience to acidic conditions. Copper is historically a popular flashing material choice, however, it is more expensive than steel. Trusted for its amazing durability, flexibility, and aesthetic, copper flashing is also easy to maintain, because it needs little to no maintenance at all. The general idea is to have a similar material to the rest of your roof for the flashing, therefore if your roof is a steel roof, you would get steel flashing.
How do you know when you need to replace the flashing?
Roof flashings are designed to last for a long time, even outliving the roof material itself in some cases. It is an underrated hero, doing most of the effort in keeping your roof intact and weatherproofing your roof. But in the eventuality that you start to notice leaks or the presence of mould on your ceiling or walls, go ahead and talk to your roof contractor as one of the most common causes for roof leaks is damaged flashings. A comprehensive inspection with a close examination of the roof will tell if your flashing needs to be replaced or repaired. Oftentimes, when there is a leak, there is something wrong with your flashing.
- Broken, curling shingles, tiles or metal sheets
Who replaces flashing?
A roof tiler will replace flashing. Most companies that advertise roofing repairs and roofing restorations will be able to fix or replace roof flashing. The first step is to contact your local roofer, get an onsite comprehensive roof inspection and find out exactly what needs to be done to keep the health of your roof and ensure your home stays weatherproofed. Contact us today for your free onsite quote.