Enameled Steel Roofing Redux

[Jim Baird]

Enameled steel roof panels are popular in our area for residential.

Most apply them to lumber furring strips, usually over OSB deck.

Have just seen it applied directly to 1/2" OSB(thru felt) for the first time.

Have been told the panels won't hold screws.

Any comments or experience with this?

[Brian G]

That's the first I've heard of it. They sometimes apply the stuff right over shingles here (if only 1 layer). Mine was put down directly over the decking, but I did use plywood myself.

Brian G.

[Jim Baird]

To answer my own question, I just talked to the manufacturer's dealer/installer about the installation.

The key to the method lies in the screw's design, which he says was developed for application of the product (Fabral) to plywood and OSB.

Problems associated with fastening he has seen derive from the use of too fine a thread screw thread.

[Jim Katen]

Originally posted by Jim Baird

To answer my own question, I just talked to the manufacturer's dealer/installer about the installation.

The key to the method lies in the screw's design, which he says was developed for application of the product (Fabral) to plywood and OSB.

Problems associated with fastening he has seen derive from the use of too fine a thread screw thread.

So, if you've got a plywood deck that remains relatively stable and a steel roof panel 20 feet long that expands and contracts with changes in temperature, how exactly do the screws deal with that movement? In my area, they rock back & forth working themselves loose and elongating the holes in the metal roof.

It isn't as much of a problem on pole buildings where the panels are attached to the narrow edges of purlins that can rock back & forth with the metal.

How does the thread design make a difference?

- Jim Katen, Oregon

[Brian G]

Originally posted by Jim Katen

So, if you've got a plywood deck that remains relatively stable and a steel roof panel 20 feet long that expands and contracts with changes in temperature, how exactly do the screws deal with that movement? In my area, they rock back & forth working themselves loose and elongating the holes in the metal roof.

I can't say I've seen that, but I haven't looked at very many metal roofs in inspections either. How much is a 20 foot panel likely to "grow" on a hot day? When I had to replace part of my roof from storm damage after about 1 year of use, the holes were still round. Climate differences perhaps?

How does the thread design make a difference?

The manufacturer is probably just referring to the finer thread being easier to strip out during installation (trigger-happy overtorqueing yahoos).

Personally I still have a pronounced preference for plywood anyway, unless you're talking about the higher-end OSB like Advantech (lots & lots-o-resin).

Brian G.