Disreputable Roofers
There are so many good roofers in the world—people who have come up through the ranks—they’ve paid their dues and learned the necessary skills. They’ve been in business for years, faced just about every problem imaginable, and are determined to do the best job possible.
Sure, they may not be the least expensive, but if you do your research and get recommendations from previous customers, the odds are that you’ll get someone that is focused on quality. Your roofer will be a businessperson who has a reputation on the line and wants to stay in business.
Terminology
A “square” is a traditional roofing measurement that means 100 square feet; it doesn’t matter if it’s 4 × 25, or 10 × 10, as long as it’s 100 square feet. It can refer to any roofing material, too, such as metal, underlayment, tarpaper, or plain asphalt shingles.
Complex roofs have multiple challenges including valleys, gambrels, dormers, hips, intersecting ridges, standpipes, chimney flashing, skylights, and other roof penetrations requiring special attention. The price will reflect the complexity as well as the choice of material, meaning it could be multiple hundreds of dollars per square.
A small, uncomplicated asphalt gable roof, fitted with standard 3-tab shingles, would likely be less than 10 squares. It’s a simple fast job, and you could probably pay less than $175/square.
The “other” guys
If a deal seems too good to be true, it probably is. Someone who has worked for a roofer during a couple of summer breaks might think that s/he and a buddy can do a few roofs and make enough for next year’s tuition. Three cheers for ambition, but many, many thumbs-down for taking on projects without the appropriate knowledge.
Companies that stick a flyer in your mailbox because they’re “in the area” are suspect. If you can’t find them in a telephone book, online, listed with the Chamber of Commerce and/or the BBB, or just about anywhere tangible showing that they’re a real business, with a real business address, you should probably steer clear.
Look for vehicles with painted-on company information, not some magnetic sticker that can be removed. Look for workers that appear comfortable and self-assured; not those standing around, blankly staring and waiting for someone to tell them what to do.
It’s tempting to try to save money
The problem is twofold when hiring the “wrong guys”. First, they’re in a hurry, racing to finish one job so they can get on to the next one. Second they cut corners in every possible way to maximize their profit. Here are some images about what can go wrong, and why…
The Vanishing Row
Shingles are installed from the bottom edge of the roof, moving upwards. You might start straight, but “eyeballing it” means deviations will creep in, and in order to reach the peak of the roof with straight shingles, one row will be obliged to vanish.
Mis-alignments are easily avoided with simple snap-lines that lay down perfectly straight chalk lines.
When these are in place getting everything straight is not a problem. If the crew installing your shingles isn’t using snap-lines, they have no business on the roof.
Insufficient Material
When someone doesn’t bring enough of a component to complete the job properly, they should just obtain some more. Under-ordering is a way to save money if they can jury-rig a “free” solution. Getting more material takes time, and remember, they are “in a rush”.
In this particular case they didn’t obtain enough ridge cap for the whole job, so they took bits and pieces of shingle trim and “made” ridge cap. 
As you can see this “masterful” job leaves a lot to be desired. Some are almost completely detached, and when you forcibly bend shingles like this they can fracture, allowing moisture to penetrate.
Sometimes the money-saving extends to nails. That’s right, the most important bit that keeps all the shingles in place. A single “square” of asphalt shingles requires 140 nails or 2.5 to 3.5 pounds of nails (weather ranging from normal to strong winds). If you don’t use enough, whole sections of your roof can just lift up and fly away.
Missed it by that much…
Manufacturers provide very specific instructions for how to nail shingles in place. It is right on every single package and you can’t possibly miss it unless you think so highly of your skills you don’t even bother to read it.
In this particular case the person installing this put the nails so high that he missed the previous row of shingles. Instead of each shingle being held in place by eight nails it was held in place by only four. Worse yet, he set the pressure so high on his nail gun that the nails were flying right through the shingles, so they weren’t really doing anything anyway.
Missing the Line
The spot being indicated is called the nailing line. This is a thickened area designed to provide extra strength. As you can see the nail is fully 1½ inches too high. This repeats all over this roof.
Cost Saving
Along the side of this dormer, supposedly “protected” by the overhang of the roof and the eavestroughing (sounds so much nicer than gutters , don’t you think?), is the wall of the dormer where it meets the roof surface. Ordinarily this is covered with bent metal “flashing” which steers water, snow, and whatever back onto the roof so that it can drain away.
When it is missing, water will
get inside, and will
cause significant damage. The installer saved a few dollars, but it could end up costing you thousands in completely unnecessary repairs. Of course these fly-by-nighters don’t care because they’ll be long gone by the time you have problems.
Starting Row
There are two ways to start a row with asphalt shingles, whether 3-tab or fancy architectural. After the drip edge is in place, you can reverse the shingle for the first row, leaving the remainder pointing upslope, or you can remove the “reveal”, which is the portion that you ordinarily see, and just use the remaining strip to create your starter row. The reason for doing this is to allow the sun-activated adhesive tar to hold down the bottom edge of the first real row of shingles. This keeps them from flopping or lifting in the wind.
Whichever method is chosen, it is essential to offset the first row by 6 inches from the starter row. If the tab-edges align, it makes a perfect spot for water to penetrate the roof. This is one of the most common mistakes made by amateur roofers. It’s generally not malicious or stupid; it’s just inexperience or ignorance, both of which can be cured with apprenticeship and time.
Racking vs Stair-casing (or Stepping)
Three-tab shingles, or just about any kind that are “racked” (heading straight up the roof, in straight rows) are almost always unwarranted by the manufacturer. There are gaps when this is done which allow water penetration. 
Some manufacturers have designed
their shingles to be installed in a racked pattern, such as the Owens Corning Berkshire collection, among others, but most require
the Stepped method. Always make sure you (or the crew) follow the instructions on the packaging. The gap between two shingles in the image is supposed to be covered by the tab to the left. This is a case of incorrect alignment.
The Takeaway
Sometimes it’s con-artists and other criminals; sometimes it’s an over-ambitious amateur; usually you will connect with a reputable, qualified roofer who is capable of, and desirous of, doing a top-rate job. If you’re going to look for bargains, you need to keep your wits about you.
Get them to describe exactly what they are going to do, what materials will be used, the length of the warranty period, and the all-in price. Saving money is great as long as it doesn’t end up costing you money in the end! Caveat Emptor!
