Asphalt Shingles - roofing materials and manufacturers

This is part 3 of our Roofing Shingles Installation guide. In this article you will learn how to remove (tear-off) old roofing shingles, repair roof deck and install roofing underlayment.

PREPARING THE ROOF DECK – ROOF TEAR-OFF AND DECK REPAIR

Nothing is more critical in roofing than preparing the surface under the shingles.

Think of it this way, when using a band-aid you’re covering up the problem area without knowing what’s underneath – sometimes there can be a wound that becomes severe. By tearing it off you would see that cut and treat it. With the roof tear-off, when the old materials are removed, you will have a cleaned deck that allows you to see more easily any potential problem. If there is reason to believe that there is the damage beneath the shingles, it is generally a good idea to tear them off.

If the old roof is still in place it’s more difficult to know what’s underneath. There may be problems with the old-roof. The deck could have rotted wood or cracked boards. Also if the deck is not sound it may not hold the nails as well.

Any of these could telegraph through the new roof and make the finished job look bad. So it’s not just the look of the roof, it’s the performance that also may be affected.

Remember, cedar shakes, tile and slate roofs must always be torn off before installing asphalt shingles – they are just not the right surfaces.

Now that you know the advantages of tearing off the old roof, let’s talk about how to do it.

Here are some suggestions for removing old asphalt or wood shingles. Professionals would use specially-designed roofing tear off shuttles, a large flat shovel, or a serrated edge shovel to remove the existing roofing materials. It’s better to use good tools because the tear off will go quicker and easier.

Use a pry bar to carefully remove galvanized soil stacks and vent flashing. Remove all debris and waste materials from the deck and then sweep it clean. On most roofs it’s better to start removing the shingles at the ridge or the top of the roofing area. Otherwise the debris may fall through the open sheeting and into the house where it could cause additional cleanup problems. Fill in any empty spaces with new boards to provide a continuous smooth nailing surface for the new asphalt shingles.

Another option is to apply a new approved deck sheeting. If the deck needs replacing, use either high-quality exterior grade plywood, sheeting boards, or the engineer wood association approved exterior grade non veneer structural panels. When installing plywood, be sure to have a one-eighth inch space between the seams over the rafter boards. This space allows for plywood expansion movement over the seams. Sometimes plywood can move enough to create a buckle that would push up roofing materials.

Make sure the decking you install is dry – failure to use dry materials can result in deck movement that will distort the overlying roofing materials.

Note, that same roof preparation techniques should be used when installing a standing seam metal roof, or metal roofing shingles, slate roofs, tile and even cedar shingles/shakes (though often, cedar roofs have no underlayment or even a solid deck, but are rather installed on perlins), and most other type of roofing materials. You should still follow system-specific installation guidelines for installing roof underlayment and the roof itself.

INSTALLING ROOF DECK UNDERLAYMENT

The proper installation of high-quality roof deck protection is the foundation on which a good roof system is built.

Always use high-quality roof deck protection underlayments like deck armor, shingle mate or leather back. Premium breathable deck armor allows moisture to escape while providing the very best protection against wind driven rain. It also lays flatter for a better looking roof

We call them deck protectors because they are critical waterproofing layer over the exposed deck. Never use non believable felts made out of polyethylene or laminated waterproof papers as underlayments over the roof deck. These materials may trap moisture and prevent it from escaping.

Premium roof deck protection is specially designed to allow moisture to escape. This means that moisture is not trapped between it and the roof deck, so it reduces the possibility of water damage, and they can assure a class A fire rated roofing system. A good roofing underlayment is also essential in ice dam prevention.

Deck armor, shingle mate and leather back deck protectors are other components required for the Golden Pledge limited warranty. Here’s what to pay attention to when installing quality roof deck protection. With weather
watch or StormGuard installed at the eaves and penetrations, the next step is to roll out the roof deck protection such deck armor, shingle mate and leather back roof deck protectors. On decks with the slope of four inches or more per foot apply one layer of deck protector.

For low slope applications of two to four inches per foot apply two layers of deck armor, shingle mate and leather back with staggered sheets. This layout is a national code requirement that many roofers do not follow but high-quality contractors like certified roofing contractors have been trained to follow this code requirement.

Install roof deck protection such as Felt / Tar Paper half lapped up the entire roof slope to promote a watertight application.

Think about these the same way you think about shingles – they have to be laid in such a way that the water is shed all the way down the roof. Otherwise, it’s like tucking your pants into your boats when it’s raining- the rain just runs down the legs of yours pants and puddles in your boots. If two or more pieces are required to finish a course, overlap the ends by at least four inches so that the water cannot infiltrate between the ends.

Also, to keep water from infiltrating, keep laps at least six feet away from end laps and adjacent courses. Deck armor, shingle mate and leather back deck should be lapped over hips and ridges at least six inches.

Finally, secure the roof deck protector with enough fasteners to hold it in place so that you keep the work surface safe and prevent the material from blowing off in the wind while you’re continuing the job.

Make certain to follow local codes when fastening deck protectors, especially in high wind areas. In the unlikely event of a shingle blow off, quality roof deck protection can provide short term water resistance until more permanent repairs can be made.

Quality roof deck protectors can also help shield the shingles from resins or other chemicals in the wooden deck that can attack asphalt and damage the shingles.

Since quality roof deck protection resist moisture absorption, it lays flatter than cheap felt. This means singles lay flatter giving property owners a better looking roof and maximum protection from roofing leaks.

Proceed to part 4: Installing roofing shingles in valleys.