Nailing Tin Roof (Dumb Question)

The Dougster · Nov 13, 2009

Pre-drilling is an excellent idea... wish I had thought of that the last time I installed a metal roof... Good thinking!

20 20 · Nov 13, 2009

jimmyj said:
Pre drilling makes the lines of screws all line up real purty. I did it on a building right by the house that everyone can see and it really is nice and tidy. On other sheds I don't really care so much so I've either done it ad hoc or used a string line. NOTE: You have to make sure the holes will line up with your roof strapping though. If the building is old and not straight it may not work.

Just seemed like a waste of time to me, string line is easier. Also like you said if something doesn't line up, now your stuck with holly roof panels.

tallyho8 · Nov 13, 2009

If you pre-drill, make sure that your drill bit is smaller than the screws. If it is larger there is a greater possibility that it will leak.

When you screw into the metal, the screw pulls the metal up around it making a sort of levee around the hole. Then even if you remove the screw the raised part helps keep water from entering the hole.

A nail does the opposite. When you nail metal it bends the metal down around the hole so that when the nail works it way loose, water is channeled down the hole.

tommu56 · Nov 13, 2009

I usually lay out holes with drywall square and a marker just dotting surface and use self drilling screws

tom

eastexan · Nov 14, 2009

tallyho8 said:
If you pre-drill, make sure that your drill bit is smaller than the screws. If it is larger there is a greater possibility that it will leak.

When you screw into the metal, the screw pulls the metal up around it making a sort of levee around the hole. Then even if you remove the screw the raised part helps keep water from entering the hole.

A nail does the opposite. When you nail metal it bends the metal down around the hole so that when the nail works it way loose, water is channeled down the hole.

Very good point.

randy41 · Nov 14, 2009

without reading all these posts, i looked at my roof and saw that when I installed it I screwed into the flat part and then screwed into the ridges where the steal overlapped. I thought I had only screwed into the ridges like I posted a few days ago.
I also think that predrilling is a waste of time. If you are concerned about screwing in a straight line then just use a straight board to line up the screws.