How To Install a Drip Edge, and Why It’s Critical For Your Roof Shingle Installation

Roofing materials serve many purposes — structure, insulation, as well as protection from harsh weather elements. One of the key functions of any roofing material is to repel rain water and get it down into the gutters.

Unsurprisingly, this is no different when it comes to asphalt roof shingles.

Asphalt roof shingles are ubiquitous in the USA, but less common in Australia. This is gradually changing, as roof shingles are starting to become a desirable roofing material for builders across the country.

It looks good, it’s tough, and it’s relatively low energy — perfectly suited for the Australian environment.

Now, regardless of whether you use tin or tile or asphalt roof shingles, the result should be the same; water runs off the roof, into the gutter, and out into the drain. Your home stays dry and your yard stays slightly less flooded.

However, how roof shingles transition that water into a gutter is a little different. For roof shingles, a specifically shaped aluminium strip, called the “Drip Edge”, is installed along the edge of the roof before the shingles are put in place.

This is what directs the water into the gutters.

Now there are a number of important considerations you need to understand before attempting to install the drip edge, let alone the shingles.

So now, let’s go take a look and see how to properly install, the drip edge.

Firstly, Why Do You Need a Drip Edge?

Tile and tin don’t require drip edges, but roof shingles do. Why is this?

Unlike tin and tiles, roof shingles are applied to a plywood deck that goes over your roof. This plywood deck forms a stable structure onto which the shingles are fixed.

We’ve discussed this process in another article.

When this plywood deck is installed, a gap is left for air to enter the roof cavity. This gap serves as the roof ventilation air intake, and is very important. It can’t be left completely open — otherwise we’ll expose the inside of our roofs to the elements — and it can’t be completely closed — otherwise it’s hardly a vent.

The drip edge helps to serve as a cover for this roof ventilation air intake. It doesn’t completely block the gap, but it does cover it enough that the elements don’t get in.

Well, that, and it helps the water go into the gutter.

Installing the Drip Edge

After the entire roof is covered in ply, the next step is to install the drip edge. There are a few key features of the drip edge that are important to point out.

The mounting plate extends 120mm back up the roof. This is significantly longer than others and provides that extra bit of protection in case any water tries to back track up under the shingle

The actual drip edge should be carefully shaped on a 45 degree angle to allow clear overhang over the gutter. A pre-bent lip will further ensure water drips directly into the gutter.

Installing the drip edge is actually quite easy to do, so long as you follow a few key principles:

Firstly, although the drip edge must sufficiently overhang over the gutter, it also needs to be straight.

As you set the drip edge in place, make sure there is at least 40 mm overhang over the gutter. You do this by measuring from the fascia to the lip of the drip edge. With help, measure at both ends, and when satisfied you have the correct overhang, drive a nail to hold the drip edge in place.

Then nail along the entire length at 100 – 150 mm spacings. This is to make sure the drip edge remains perfectly straight.

When complete, you’ll end up with a very neat edge that’s ready for the next step of the Asphalt roof shingle installation process.

Finish With GAF Roof Shingles

We’ll have another article about installing the roof shingles themselves.

When considering any roofing material, you obviously want the best. When it comes to asphalt roofing shingles, that’s an easy choice — GAF asphalt roof shingles. There are more homes in America with GAF roof shingles than there are homes in Australia. That should tell you something about their quality.

Final Point

Tin and tile roofs are great and offer distinctly Australian finishes to houses, but they’re not the only options. If you’re after a unique look to your home, or are building a quintessentially American design like a Hamptons, go for asphalt roof shingles.

Your home will stand out amongst the crowd, and have an authentic finish many other Australian-built American-style houses just don’t.