Roof flashing waterproofs and weatherproofs–these thin strips of waterproof metal flashing prevent water and moisture from invading your home or structure, keeping you dry inside. In short, roof flashing is weatherproofing for your home. It protects the edges of your roof and any walling and vertical surfaces attached to the roof plane.
Without proper roof flashing, water can infiltrate gaps between building materials, eventually finding its way into your home, leading to water and structural damage. Roof flashing also plays an essential role in protecting the structural integrity of your house from wind forces, which could result in falling debris, collapse or a flying roof.
And as Sydney marks 2022 as its wettest year since records began more than 160 years ago, the importance of structural integrity and properly installed roof flashing have never been more crucial.
Speaking to the Sydney Morning Herald, the director of remedial company CJ Duncan, Ben Duncan, who works on large-scale projects, said, “these rains are a real stress test and what it is showing is that [buildings] either need maintenance because they’re old, or they’re new, and they need to be rectified to ensure they can withstand this sort of weather.”
Waterproofing is the most common major issue, followed by fire safety in NSW strata buildings, with 23% experiencing severe defects.
Whether it’s an apartment, a house or a commercial building, roof flashing waterproofs and weatherproofs and is essential for structural integrity.
Roofing professionals must adhere to the Building Code of Australia’s standards, specifically the Installation Code for Metal Roof and Wall Cladding (HB39-1997). Roofing professionals must also comply with AS 1170.2:2011 whenever roof flashing is installed in cyclonic areas.
It is the responsibility of a licensed professional building inspector to evaluate flashing installation to verify compliance with building codes and standards.
Poorly or incorrectly installed roof flashing can lead to structural integrity issues and could see you spending even more on repairs like Jo and Tom Rosenthal.
Weatherproofing Your Home
More than just a top cover for your home, apartment or building, roofs must be specially designed to ensure they are appropriately sealed to prevent structural damage caused by environmental stressors.
Wherever flashing is installed is typically the most prone to water ingress and must be protected. Protruding parts of the roof or wherever the roof connects to a wall – chimneys, skylights, dormers, vents – are particularly vulnerable to water ingress.
Roof flashing is installed once the roof frame is in place and is nailed or stapled into place. Typically installed over roof shingles and other roof materials, roof flashing prevents water from seeping under the roof. Any gaps between the flashing and building materials are sealed.
Roof flashing is installed using a combination of nails and sealants in the following water-prone areas:
- Side walls/ Front walls: Where the roof surface joins a wall.
- Valleys: Any low point where roof slopes join.
- Protrusions: Vents and Skylights.
- Edges: Eaves, gutters, etc.
Although most homes and structures have only one roof, various types of flashing can be installed, depending on the location or application. Lead coated or lead flashing was the most common roof flashing material. Nowadays, builders prefer less harmful materials like aluminium, copper, galvanised steel and bitumen.
Roof Flashing and Wind Forces
Wind forces are a critical consideration for any structure. Much like a storm door provides an extra layer of protection against bad weather, Roof flashing is critical in keeping a roof over your head. Wind forces can wreak havoc on your home if flashing is not installed properly, especially in cyclonic areas.
Wind forces impact the roof’s topside and its underside. These forces are categorised as inward or outward. Inward forces can cause the roof to collapse in on itself, while outward forces can lift the roof completely. These forces can also cause damage from flying debris, falling trees or the collapse of adjacent structures.
Is Your Roof Waterproof?
Roof flashing is a vital part of any structure. Adequately installed roof flashing waterproofs and weatherproofs and is essential for structural integrity. Able to intercept, collect and discharge moisture away from the roof or into the stormwater drainage system, roof flashing prevents water from entering your dwelling and wind from destroying it.
While every building in Australia must adhere to the building codes and regulations, waterproofing and weatherproofing aren’t forever.
If you suspect roof damage or notice an increase in moisture in your home, it may be time to inspect for water ingress in the roof. Call the experts to see if your roof is water and weatherproof.