Nails vs. Screws

The final nail in the "Nails v. Screws" coffin...

The debate about what to use to fasten your new steel roof onto your old asphalt roof, nails or screws, seems to never go away. Let's nail down this coffin and bury it once and for all.

First, the back story...

Metal expands and contracts with heating and cooling, a physical phenomenon. Metal, if held stationary, like on your roof, and exposed to heat and cold, like during summer and winter (and even during daytime and nighttime), will fight to move during expansion and contraction. This fight occurs at the points where it's fastened, on the fasteners. That puts stress on the nails or screws over time and ultimately loosens them. Under enough repeated stress the fasteners can tear through the roofing material. Ultimately the fastener heads can break off. Each of these effects creates a roofing system failure and potential water leaks.

Roofing failures occur unless the steel roofing system is designed with the natural and normal expansion and contraction process in mind. So it is with Hy-Grade's steel roofing system with its unique shake design, including fastening socket and fasteners: nails. The design of this socket allows steel expansion and contraction out, up, and away from the fasteners (nails) never to stress or loosen them. An additional benefit of this design: water never flows over the nails, always around them, never to leak.

Since 1988 Hy-Grade Steel Roofing System has designed and tested many different shakes and ways to fasten steel roofs over existing asphalt roofs including screws. The main problem with screws is they're most often over-tightened causing dimples indicating their threads will bind the shake preventing any movement during expansion and contraction…unwanted stress.

Every steel shake, fastening system, and fastener designed and tested has failed to live up to Hy-Grade's high standards and specifications except one, its current steel roofing system. Hy-Grade manufactures, sells and installs one ideal shake profile (in seven perfect colours), with its unique fastening socket and fastener (2" hot dipped galvanized nails inserted at a precise 30°angle), into the spruce wood strapping system attached to the old asphalt shingled roof. This ingenious roofing system remains the best system to stand up to Ontario's harsh temperature extremes for at least 50 years. With all this in mind, from where is the debate about nails and screws coming? It comes from companies that either can't or don't use nails. And experts will agree, along with most with common sense...

...the best fastener is the one designed for the product being fastened, in this case:
NAILS as the fastener in Hy-Grade's steel roofing system.