Asphalt Shingles - roofing materials and manufacturers

This is part 2 of our Roofing Shingles Installation Guide. In first part we discussed first steps that you need to take, when installing a new roof, such as planning, measuring a roof, choosing roofing materials, and the actual roofing shingles installation process.

In this article we will look in depth into installation of roofing shingles, and discuss proper roof nailing patterns and techniques to ensure best wind up-lift and blow-off prevention. We will also show you the right way of installing shingles in filed, and why you should avoid racking the shingles (staggered vertical formation).

Let’s look at how shingles should be nailed down:

PROPER ROOFING SHINGLE NAILING

If four nails are required, the preferred order to apply nails is one, three, two, four. But one, two, three, four is also acceptable. When the nails are placed in or above the self sealing strip or a nail guideline we call it high nailing. High nailing can reduce the strength of the seal, resulting in lack of adhesion which can make the roof more vulnerable to blow offs.

Video of how to properly nail roofing shingles:

Follow the application instructions on each shingle wrapper to ensure proper nailing. Proper nailing is required on all Manufacturer’s Warranty installations.

If the deck is plywood or OSB, the nail should penetrate through the back of the deck to meet most local codes. If the deck is solid wood then the nails should be long enough to penetrate at least three fourths of an inch into the wood deck.

Remember that there may be a number of shingle layers at the hip and ridge that may require longer nails for proper installation. Use only zinc coated steel or aluminum, ten to twelve gauge barbed or smooth shank roofing nails with heads three-eighths to seven-sixteenths inch in diameter. Don’t use common nails since they are not designed for roofing and can rust or corrode. Nails should be driven straight, so the head does not cut into the shingle. Heads should be driven flush and not sunk into the surface of the shingle. Make sure to follow the individual roofing shingle manufacturer’s nailing instructions for proper nailing location. This will help prevent moisture from getting into the roofing system and could prevent premature failure and blistering.

As you go along remember to correct any nailing errors. High nailing is probably the number one installation mistake made on roofing shingles. It’s one of the biggest causes of blow offs. Angled or under-driven nails are a problem too.

See this angled nail – it can poke a hole in the shingle above it. And like an open-door rain will flow right through it into the building. Under driven nails can actually worm up due to deck movement and like an angled nail poke through the shingles, making another hole on the roof. Be certain to take your time install nails properly – flat to the shingle, not angled, and in the correct location. It really just takes a couple seconds longer.

PROBLEM WITH RACKING SHINGLES

Before we go further I want to make a quick comment about shingle racking.

Racking is the straight up application of shingles, and although some contractors use it on three tab installations we do not recommend it for any type of shingles – whether laminated or three tab. Racking of the shingles most often occurs on hip roof types, but is also common on on gable roofs. Most roofing contractors use shingles racking to speed up the roof installation process, but it can result in improper roof installation.

Racking often makes color variations more noticeable and can lead to shingle damage. It can also result in missing fasteners, which increases the risk of blow offs.

Another problem with racking, especially in cold weather is that when you bend a shingle to slip it under another, you may damage or break it. This may not be visible at the time of installation.

Roofing Shingles installation – Part 3: Roof preparation – tearing off old roof and installing roofing underlayment.