Screw spacing on metal panels

[green.bubbly]

Probably by next weekend I will begin installing the PBR steel panels on my garage. What is the normal spacing/placement of the screws? I will have a top purlin and a bottom base plate. In between that, I will have three purlins for a total of five lines of screws.

This is my garage...

 

[Possum]

One next to each rib, and on the ends of the sheet one on either side of the rib. Check the manufacturers recommendations.

 

[mark52621]

One beside each rib. Not through the rib, beside the rib.

Not that you asked, but here are my steps to put on a metal roof:

1 Pull sheet of tin up to the roof.

I stand at the peak of the roof and pull the sheet up to me using a vise grip tied to a rope. Place scaffolding at the edge of the building to support the sheet as it comes up the roof. The scaffolding also gives you a place to stand when screwing down the bottom edge of the sheet.

Spend extra time getting the first sheet square with the roof and double check the fit of the trim for the corner

Also, the ribs can be overlapped incorrectly. Make sure you have the proper one on top and bottom.

2 Screw the top of the sheet to the peak of the roof

3 Use a straight edge and mark where the screws go.

If the tin is thin enough you can feel where the furring strip is, but it is much easier to put a screw through a dot. Especially after a few hours of work.

3b Optional: caulk where the sheets overlap.

Screw down the sheet as normal, but don't put screws next to the rib where the sheets overlap. Instead move on to the next piece. After all of the sheets are on the roof then caulk between the ribs and put in the finale screws.

The easiest way to do this is to use a couple of blocks of wood to hold the ribs apart while running a thick bead of caulk between the ribs. Pull out the blocks of wood and put in your finale screws.

4 Check for extra holes.

Go inside the building shut the doors and look up. Any holes in the tin will be easy to see. Use white caulk to plug the holes.

If you use clear the light will keep shining through.

Anyways, good luck.

I forgot the most important rule, don't fall off!

 

[Deltarat]

Here's a trick for the side to keep all the screws in a straight line. Stack all the side panels with the ends even. Measure the purlins on the side wall and transfer the measurements to the panels. the drill 1/8" holes beside the ribs through all the panels. When you install the sides the screws will be in a perfect line. You can do the top that way, but they are not as noticeable as the sides.

 

[green.bubbly]

Thanks for the answers and suggestions. This is one of those things that I fail to think about until it is time to start doing it. Then I realize I do not know where to put the screws and have to waste time researching instead of working.

My building came with rolls of butyl tape to seal the sheets.

Thanks again.

 

[NUTTSGT]

What I love about the GJ, always people offering great advice.

 

[Nighttrain]

Deltarat has the best idea!. Check my build link, I just finished a 24x32 barn using Mueller metal. I also pre-drilled the sheets while they were stacked up. The Butyl tape was only used for the roof. See no need for the wall panels. Also I placed a screw every 30" on every rib (roof and walls.) These were the screws that were only 1" long. Also as possum stated asked the manufacture for their screw placement plan. Mueller has one and it is an engineered plan to ensure that the panel is attached correctly. Good luck on your garage.

 

[nehog]

Uh, the building manufacturer should have specified that, and I'd strongly recommend you contact them and get their advice.

 

[SARG]

Just for information sake......... My nephew is a union carpenter and has done a multitude of buildings with metal roofs and siding. He advised that they usually pre-drill the sheets while they are on the ground bundled.

 

[5lima30]

+1 on stacking the panels on the ground and pre-drilling holes. It makes it SOOO much easier screwing them down when on a pitched roof! YMMV.

 

[Possum]

When you pre-drill make sure you have pressure on the sheets so the drill chips cant get between them and scratch the paint. With a 1:12 roof pitch I am sure you must need some kind of sealant between the overlapping sheets. I have seen more than a few manufacturers that recommend that for anything 3:12 and flatter. Mark52621 gave you some great advice.

 

[green.bubbly]

Great advice from everyone. I was looking at the building plans that came with the building and I did not see anything on screw placement. i will give them a call on Monday to verify what the specifications call for especially since this is a wind rated building in hurricane prone country.

I ordered 20 rolls of butyl tape not realizing that the building came with tape already. I should have enough to do the walls as well. I agree with drilling the holes through a stack of sheets as I hate uneven screws on metal buildings. I read in a few places about making sure all the metal shavings are swept off the sheets because they will quickly rust if left on the sheets.

If I keep getting great advice like this, I might even tackle erecting my 38x46 steel home as well. Actually, that ain't gonna happen as that building has some seriously thick and heavy beams. I like a good challenge but I am no fool.

 

[sdetweil]

just finished my 30x40 Muller.. the side walls were one screw between ribs, base, girt, top, and three in the overlapping rib.

so, that is 12 screws per sheet. (this over batt insulation).

on the roof there were screws on each side of the rib, base, 2 pulins, so 6 x 3 = 18 screws per sheet. then the peak sheets, with 6 screws each side.

Sam

 

[slip knot]

I've used the pre-drill method on new construction but wont use it again on an existing building re-roof. on a new square building it will work great but on an unsquare building it kinda ***** to get 2/3rds across the roof when the purlins run out and the screws dont hit anything!
on older construction I'll normally sticky tape 3 sheet together on the roof eave and line it up with the eave line. usually only put a screw or two in for each sheet. When all the sheets are up I'll go back and chalkline the purlins and run the screws out then. has worked OK for me so far.

 

[nehog]

I've used the pre-drill method on new construction but wont use it again on an existing building re-roof. on a new square building it will work great but on an unsquare building it kinda ***** to get 2/3rds across the roof when the purlins run out and the screws dont hit anything! ...

I was going to say the same thing, one must be absolutely sure they pre-drilled holes will hit what they need to (the purlins.)

With steel buildings, the drill tip screws make pre-drilling rather unnecessary anyway, the amount of work going through the sheet is nothing compared to the purlin.