Roof flashing is a lightweight material, often made of steel, used by professional roofers to direct water flow away from main areas of the roof. Flashing is primarily installed at joints in a roof or as part of a larger waterproofing system. In many modern buildings, you are most likely to notice flashing around objects such as vent pipes, wall, window and door openings, skylights, and chimneys.
If the flashing is correctly installed, it allows water to run down its side and flow towards the shingles instead of pooling on the roof or dripping between small crevices and potentially into the house itself.
In fact, improperly installed roof flashing is one of the most common reasons for roof-related leaking. Leaking of this kind can also lead to wood root and deck collapse among a range of other highly damaging problems.
In the article below we will be covering some basic information about different types of roof flashing as well as how you can best maintain it and repair it if required.
Types of Roof Flashing
Roof flashing comes in a variety of different types, depending on the exact function it needs to perform. Below are the most common types as well as the most common areas on a roof where you are likely to find them:
- Step Flashing – ideal for areas where the roof meets a wall, step flashing involves cutting, bending, and sealing individual pieces of flashing as required by the roof
- Continuous flashing – unlike step flashing, this involves a single piece of flashing being used behind the exterior cladding and the weatherproof barrier on the wall
- Saddle flashing – this is a curved type of flashing, generally found at the edge of roofs or around chimneys and skylights
- Valley flashing – the valleys of a roof are the straight lines that form when two different planes of a roof meet, and they handle a very large amount of water run-off. Thus, whether closed or open, they require adequate and durable flashing. Valleys are referred to as open if they are visible or closed if they are not.
- Chimney flashing – as one of the main penetrations in the roof, chimneys require special flashing along the bottom, around the sides and even at the top to keep them completely waterproof.
- Skylight flashing – like chimneys, skylights may often benefit from their own central flashing, or may alternatively be treated to a combination of continuous, step and saddle flashing to ensure complete coverage.
- Drip Edge flashing – found at the rake and eave edges of the roof and applied mostly under the roofing felt, drip edges are very important in preventing water from pooling and seeping under the roof.
Roof Flashing Materials
There are a number of different materials used for roof flashing, each with their particular pros and cons:
- Steel roof flashing – this is the most popular choice of roof flashing material. It is corrosion resistant, as well as malleable and easy to install. It can however be very shiny when first installed.
- Lead roof flashing – this is by far the most durable type of flashing you can have installed and the least likely to crack or melt under the pressure of varying temperatures or weather patterns. However, it requires highly qualified specialists for installation, and it can be very costly.
- Aluminium roof flashing – the most lightweight type of flashing, aluminium is easy to form and instal but does need to be specially coated if it comes in contact with masonry.
- Copper roof flashing – mostly used around chimneys, copper flashing is durable and takes soldering very well, but can show signs of discolouration much sooner than the other materials mentioned.
Does flat roof flashing exist?
It does, and it is equally as important as sloped roof flashing with the crucial role of creating and maintaining a waterproof barrier for your building. Damage caused by storms or heavy rain can wreak just as much havoc on a flat roof as they can on a sloped roof, making it imperative that you invest in flashing.
Flat roof flashing can be made of metal or rubber, although the best type usually utilises a combination of the two. This is because the rubber components can act as a fail-safe in case the flashing fails at any point, protecting the building for longer while you wait for a replacement.
How to maintain roof flashing?
In order to ensure you get the most out of your flashing, it is important to consider how best to maintain and care for it in order to ensure any short-term damage or wear and tear.
One of the easiest ways to ensure your flashing will last longer is to make sure that there are no loose nails or holes around the edges of the flashing. You can also regularly check in on the state of the sealing around the edges and top up or cover any cracked or crumbles cement or caulking as appropriate.
Additionally, rust inhibiting metal paint can also assist in keeping galvanized metal from rusting for longer, thus lengthening the life span of your flashing.
If in doubt, however, never hesitate to call a roofing specialist for assistance.
How to repair roof flashing?
In general, repairing roof flashing only requires a four-step process. This involves prying up the roof tiles around the damaged flashing and potentially removing some undamaged pieces of flashing as well. Next, any left-over sealant or cement will need to be removed. The third step is to check if any damage has made it past or under the flashing to the lower parts of the roof. If it has, this will need to be repaired before flashing can be reinstalled. Finally, new flashing and tiles can be installed in the required areas.
While there are DIY kits and guides that can help you through removing and replacing flashing yourself, flashing is a crucial part of any roof and so it is always the best practice to consult a professional.
At RoofServe LTD, we as a roofing expert have a wealth of experience in dealing with roof flashing among a range of other roofing problems.
If you’re worried about a leaky roof or you think your flashing may be worn or damaged, give us a call on 01274 974575 for a no-obligation survey!