metal building screws

[DJ54]

They make a butyl rubber caulking for gutters that roofers use around here. Run the screw in, then put a dollop on the entire top, and seal them that way.

 

[Cord]

The screws should be run in so the washer bulges and is flush with the edge of the washer. This is enough compression to seal the washer, but not split the washer. Screws set like this should seal.

I would not recommend trying to seal the roof using spray foam. The leak will still be there, but the foam will conceal the mosture. Eventually the water will travel until it finds lumber causing rot.

 

[DJ54]

I've found using the cordless impact drivers much easier to drive screws, then a cordless drill. Much easier to get it stopped when you want it to, instead of the drill running a bit more to stop. I got in the habit of almost getting there, then bump the switch to the proper set of the screw.

 

[Billrog]

From experience you don't put caulking on a metal roof unless your filling a hole where the bolt miss the perling
any other advice is bad advice. You should post a pic. of where the screws are placed on the roofing. Are you sure it's not just condensation. Caulking is used between snow stops and the roofing under where the screw goes through. I've use 1/2 doz. different types of roofing screws and never had one leak yet but the ones with neoprene washers are the best.

 

[gwstang]

I have used the white cool seal product from Lowes store. It is made for roofing coating and will seal the screw/head/washer up tight. Just dab a little on/around and be done with it. You have a white roof so it would be excellent for your usage and would last forever....since you are like me and don't want to get on a roof anymore than you have too.

 

[Handloader109]

First, the advice to not screw down too tight is spot on. If you have bent metal where the screws are, then it is too tight and will leak. I had a shop in MS and it never leaked due to the screws. If it is dripping when it isn't raining, it might be condensation. Insulate when true leaks are fixed. Silicone is the worst thing you can use. Get the Henry's or other urethane sealant. And stay off the roof as much as you can. You will create more leaks.

 

[Greenland South]

Having done and inspected several metal roofs, I've learned a few things.
Carefully laying out the strapping, pre drilling all the panels to the root diameter of the screw, not driving them to tight and make sure they go in straight. If for some reason you miss the strapping with a screw, it's best to put a piece of strapping under the hole and re drive the screw.
If you do develop a leak around a screw head, make sure the metal is flat and barb free around the hole before putting a new screw in.

 

[Billrog]

Putting a piece of strapping under the hole and driving a new fastener is good advice.

 

[JSanders10]

I used the Lexel clear silicone to make some repairs on my barn roof, and it's worked great.
We replaced some screws as well, but on any small pinholes in the room, a squirt of the Lexel worked great.

 

[/pine]

FWIW...
I did not see it mentioned and it likely does not apply to typical metal roofs (leaks)...
...But on a quality metal building there are several different types of screws used just on the sheet metal exterior...they all may look the same at a first glance (all have sealant washers, and all may be self tapping etc.) but they are meant for different purposes...i.e., stitch screws, seam screws etc., etc...