What is roof flashing?

One question the team at JN Roofing is asked quite a bit is what the metal sheeting that is often seen along upright walls and chimneys. This is called roof flashing.

The next question the homeowners invariably ask is usually what is the purpose or need for roof flashing? A quick explanation is that flashing helps reduce the chances of water leaks along your chimney, vertical roof walls or other areas where shingles butt up against upright objects.

Flashing helps keep water from getting underneath your shingles.

When you have proper flashing in place it moves water away from potential problem areas. When done right, flashing that is properly installed can help protect your roof for decades. Roof flashing can be made from many different materials.

Copper flashing – If you are looking for the most durable flashing option, it would probably be copper. Not only is it basically maintenance free, as it ages it takes on a dramatic green patina which can be very striking particularly if you take the time to properly select a complimentary shingle color.

Lead flashing – Much like copper, lead is an extremely durable flashing material. Lead flashing, if installed properly, can last as long as you own your home or even longer. Leads durability and long lifespan is partially due to it being a softer metal, which allows it to expand and contract better with different seasonal temperatures (something homeowners from Barrie, Simcoe County and surrounding area know a great deal about). Lead flashing also tends to resist water damage better than some of the other flashing options.

Steel flashing – Steel flashing will more often than not be galvanized and have a zinc coating which can help protect against the elements.

Aluminum flashing – Inexpensive and while it is relatively durable, it will be the least durable of the options. As a softer material, aluminum flashing is easier to bend, manipulate and work with, which makes it an excellent choice for complicated applications spots.

While there are several types of roof flashing application options, here are a few.

Step flashing – This is a single piece of metal applied along a roof and sidewall with the goal of preventing leaks. This is not as an effective method of flashing when compared to other options as heavy rains can in some cases penetrate past it.

Drip edge flashing – found along the edge or eaves of your roof. Helps reduce the likelihood of rotting fascia.

Step flashing – Step edge flashing is probably what most people think of when you explain flashing to them. Exposed rectangular metal pieces that run along the length of chimneys and abutting walls. A great application that helps reduce waters ability to get underneath the shingles.