The asphalt composition manufacturers have made matters simple with a nail line. On the wrappers are instructions that explain if four or six nails are needed, depending on the size and weight of the roofing, and for exceptions such as steep slopes, which can require more nails. Mansard roofs require more nails.
On the rake edges there should be two nails instead of one. Wind is the obvious reason but when the roofer trims his shingle there is a pull or stress on the piece that makes the tab want to pivot. This weakens the nail torque. Plus, did I mention wind. As in previous blogs I mentioned the use of professional starter shingles as opposed to the twenty year three tab put on upside down and backwards.
The nail should penetrate at least past the tapered part of the nail so that the fat part of the nail shaft should pass through the deck, not leaving the barb partially submerged, even though this is upside down.
Ridge nails should be longer than the field nails because they need to pass through more layers: the roofing itselt and the ridges beneath them Ridge is like a reroof or second layer. Decorative and enhanced ridges need even longer nails. Nails for ridge over vent ridge need to be even longer. Enhanced ridge over vent ridge need huge nails, up to three inches. Read the directions. Read, read, read...The info is there and the manufacturers have tested and tested their products and have seen what happens over time. Think of the roofer as the criminal and the manufacturer as the cops. The police have amassed data over time and school their people. Criminal become convicts because they committed crimes but the criminals that study crime books are going to make it longer. At least on Judgment Day our sins will be brought out. Plus the manufacturers have their deputies: the certified roofing contractor.That be me. We are at the top of the food chain.
Staples and pneumatic nails are allowed but I'd never allow them on my home, or yours either. Only stone coated steel roofs like Gerard and Decra may be applied with air nailers. Those nails should not be some cheap nail off the shelf at Lowes or Home Depot, but a long life nail tested in the salt mist or spray manner.
Again, long life roof and cheap nails make for a bad combination.
"Why did that convict roofer use $50.00 a box nails on our Gerard roof instead of $100.00 a box nails on our $35,000.00 roof? He only needed three boxes. I would have paid the difference. Now the whole roof is stained and about to fall off."
Coulda, woulda, shoulda.... didn't check the ethical/moral quotient on your roofer did you?
These thinner but stronger composition asphalt roofs are flimsy when warm and brittle when cold, with a texture that changes with expose to sunlight. Nail gun regulators, if the roofer has one at all, are not adjusted with every shingle. Plus, a roofing hatchet will only drive a nail flush because the hatchet is larger than the nail whereas the nail gun's driver blade is the same size as the nail head. Despite the bad reputation of the roofing staple gun, the conundrum is that the stapler is superior to the air driven nail gun. Enough said.
The nails today are cheap, made in China, and are so shiny that I believe the labeling of "galvanized nails" is a deceptive trade practice. There is an earlier post in this forum about Maze Nails, the last American nail manufacturer. Their nails look like the nails of my youth, gray. They claim to have seven times as much zinc on their nails but zero to whatever Maze has is an infinitesimal amount.
We've all seen the nails rust away before the service life of the roof is over. The teeth are fine but the gums have to go. The weakest link determines the strength of the chain.
Slate roofs require copper or stainless steel nails. Period.
Lifetime roofs should use the Maze nail.
Exposed nails on stone coated steel roofs should be coated and have a rating in accordance with the salt mist test.
I shot the sheriff, but I did not shoot the deputy...
Jon Alan Wright
Jon Wright Roofing, Siding, and Windows
1915 Peters Rd., Suite 310
Irving, TX 75061
Master Elite Roofer: (Scroll to the bottom)