When To Replace Asphalt Shingle Roof
Today we're going to look at the process of looking at a newly installed asphalt shingle roof inspection for proper manufacturers installation instructions. We'll look at what a roof inspector might look for and find, as well as some typical mistakes that are often made when asphalt roofs are installed.
The edge of the roof where the water runs off is called a drip edge. A drip edge typically there's two or three problems with a new installation. One would be the starter course. The starter course is the course of shingles laid down first as a roof installation is put together. On top of that goes the first course, so well you typically see on the drip edge is the first course. The starter courses is actually just below it.
So what's supposed to happen with this kind of roofing system, if the starter course is put down correctly, is that the first course actually adheres to it. The typical case of a starter course not installed correctly is obvious when there's no adhesion of one to the other. The drip edge courses end up not being bound together like the rest of the courses will be.
The other issue is the felt underneath the shingles has no drip edge flashing. The flashing is a metal strip that basically just protects the piece of drip edge molding from water damage over time.
Some of the penetrations on a rooftop or other points of contingency when it comes to new installation, one thing that needs to be looked at is where the flashing is located. What I mean by flashing is basically that you first have "the boot", which is the piece that the items penetrate through, then you have a piece of flashing that are usually nailed down, or stapled. In this case they've sealed over a nail head which is perfect. Over time those tend to leak.
Same thing on furnace vents and water heater vents. We have what's called a storm collar, which basically protects the boot, or the piece below where the vent pipe penetrates through the roof. The storm collar should always be low over the joint and sealed. With a furnace vent, it's same thing; making sure all the nail heads are sealed, and the storm collar is down tight as well.
Now chimneys are probably the one penetration in a roof that are known to leak the most. Something that often is found missing is the cricket. Crickets are required for building code on any chimney that is 30 inches wide or greater. In many cases you'll see that you have a lot of surface area that is above the chimney, up to the ridge, where all the water is going to collect and divert down on top of this area. So a cricket is basically a piece of sheet metal, in most cases, or sometimes a constructed roof, and it diverts the water around the chimney to prevent it from blocking up. It also prevents debris from blocking up behind the chimney, which can cause damage. Another name for a cricket is also a saddle. No matter what you call it, the flashing on these should be nailed down and the nail heads should be sealed up.
The area of the roof where the water does not roll off is called a rake edge. Flashings are recommended, and drip edge flashings, like we discussed earlier, are required.
One of the most susceptible areas for water damage on a chimney is going to be the bottom corners. It's very likely to find some water damage, and you want to be sure that if there is damage, it hasn't just been shingled over and not repaired. In a lot of cases the guys that put these roofs on are in a hurry. They've got more jobs to do and the faster they can get this roof on, the lower the labor cost. The problem is, if you install the shingles in a way that exposes any type of nail head, this becomes a leak point. It usually doesn't happen right away, but it can happen very quickly, depending on how the roof wears. Generally you will have water penetration at an exposed nail head maybe 10 to 12 years down the road.
What you should be looking for is to make sure there are no nail heads exposed around any shingles. Each section of shingles is called a tab. Another very important thing to look at is the way that the tabs are the shingles are fastened. You do that by just lifting up some of the new ones. As as the roof begins to get hot from the sun, the adhesive strip along the edge is going to glue down one tab and make it pretty hard to get up without damaging it. So looking at a roof on a cool day, or looking at a roof right after the installation is the best time.
The edge where the two shingles come together are supposed to be three-quarters over from the edge generally speaking. Something to look out for where these meet is how deep the nails has been driven into the roof. The problem if they get driven in too deep is that if a high wind were to get underneath it, very little of that nail head is left to be compressing down on the shingle, and the shingle can actually incur some damage. So by driving the nail head too deep, there's the possibility of the shingle lifting off and away from the nail more easily, causing damage.
So as you go up looking at how the shingles have been nailed down, you're going to want to look for consistent patterns as well as distances from the butt edge. Also, look for nails that might have been driven at an angle. It's the same issue as before if the wind gets underneath the tab and lifts it, especially if the angle is pointing over toward the point of the shingle, then we do tend to have more wind loss. So checking these some areas at random is the best way to determine whether or not the roofer did a good job.
Something else to be aware of is that it's not unusual to have a couple of different guys on site from the company doing a roofing job. So you might have one guy using nails and the other guy using staples. It's the same issue with the staples - if you have the staple at a bad angle, it can be a problem because as the shingle comes up under the wind, if the staple is at an angle, it can actually tear across the shingle and it could come off real easy. To be right, inspect to make sure the staple should be parallel with this edge of the shingle going across. So we should see those running straight horizontally only. But again, these guys are often in a hurry and the idea is to get out of here as fast as they can without asking any questions, so they can get on to the next one. And often they're not standing in a perfect location that allows them to hit these things straight, because of their wrist angle.
With a plumbing vent, you might see a hybrid rubber / metal flashing for the boot. In hot, sunny areas like Arizona, these aren't the best way to go because they take on an enormous amount of UV radiation from the sun. Anything made of rubber like this is going to really get beat up by the sun. It'll probably last the 20 years the shingles are supposed to last, but it wouldn't be unusual to see them fail prematurely. Also the plumbing vent is supposed to be painted with the latex paint to prevent UV damage as well.
Don't wait to learn that you have a roof leak by finding water on your floor - request that a professional roof inspector, who knows roofs backward and forward and understands how insurance coverage works, come and access your roof and help prevent future damage before it's too late. Roof inspections today can save you a mountain of grief and work tomorrow.
Call around and you may even be able to find a local roofing business with inspectors who are willing to provide a free quote to check the health of your roof and look for needed repairs. Once things are in order, it's a good idea to regularly have your house checked for potential issues through routine inspecting. In every community you'll find professionals more than happy to go up and check the condition of your roof, report back and fix any problems before they turn into a major roof repair project and a potential safety hazard to your home and family.