For some reason the advanced search is giving me no results. Anyway, can anyone give me a few pointers on installing metal roofing? I’ve got 29 gauge, 3 foot panels that I’m installing over skip sheathing, with rubber gasketed screws. I’m mainly wondering where and how often I put the screws- one row each edge and down the middle of the panel, every foot of the length?
I also need to know how often to screw down the ridge cap.
Thanks.
zak
“so it goes”
Replies
Just use common sense. A screw in every flat part in rows. Make the rows separated maybe three feet. Some would screw the screws in the raised part to minimize elongated holes caused by the expansion of the metal as it heats and cools. Here I have seen them screwed in the flat parts with good success, on jobs that are 7-8 years old. This is in Tulsa, OK.
Really, I think you need felt under the metal roofing. It is up to you to lay a deck over the skip sheathing. I would (an am) put down a deck over the skip sheathing and put two layers of felt down and maybe a layer of asphalt roofing that comes in the rolls, then put the metal roof on. Don't forget to renail the skip sheathing :)USe common sense, it will work as the day goes on.
Handyman, painter, wood floor refinisher, property maintenance in Tulsa, OK
I actually reframed and put the skip sheathing back up- it's just a little garage (12' x 20').
I'm curious about the usefulness of felt- it seems like it would sag between the sheathing if any water got back there. It also seems like I would run a very high risk of putting my leg through the felt when I stepped in the wrong spot. zak
"so it goes"
That is true. The felt would obscure the view of the skip sheathing too so it would be hard to tell where the screws should go to avoid the gaps.Handyman, painter, wood floor refinisher, property maintenance in Tulsa, OK
I looked into this myself. I would contact the manufacturer for install specs if I were you. And many I spoke to said the rubber gaskets fail over time and need to be replaced. Was told the standing seam with hidden fasteners was better.
good luck
kevin
None on the ribs, the gasketed screws are designed to be placed in the field.
Google Metal Sales. They have bountiful instruction guides. Be sure to payu attention to whih is the male and which is the female side of the lap. I CAN'T BELIEVE HOW MANY PEOPLE HAVE ASKED ME TO HELP THEM FIGURE WHY A ROOF IS LEAKING WHEN THEY HAVE INSTALLLED THE LAPS BACASSWARDS
I use vice grips to hold the lap in alignment while screwing.
I also predrill several pieces at once while on the ground. This presumes that you have neatly aligned your skip sheathing though.
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I looked at the metal sales site- it answered most of my questions. It showed where to fasten between ribs, but not how often along the length of the panel. I think coonass answered that question though.
Thankszak
"so it goes"
OK, I,m in hurricane area so mine is different. I got 5/8 plywood on trusses. 30 lb felt. then metal roof, screwed on flat every two feet. screwed on each side and one in middle. Of those that lost they roof during the last couple winds storms, they had metal roof on skip sheating or purlins so, if you got any chance of a wind storm, you going lose your roof.
Edited 5/3/2006 9:25 pm by brownbagg
You are assuming that there is an equal mix of plywood and purlined roofs.
Probably 90% are on purlins so you saw more of those.KK
One thing I might add, as you are putting the metal down pull a measurement from the far end of the building every so often just to keep the top and bottom tracking the same. Most people tend to put their foot down beside where they are screwing.If two people are screwing and applying different amounts of pressure with their foot on a ridge then the metal can flatten just a little more or less causing the top or bottom of the metal to be a touch wider.
Also, don't run the screws down so much that the washers bulge way out from under the heads.UV rays from the sun can deteriorate them then.
Don't know if this helps or if its right, but its how I was taught and I generally have good luck with it.
The fastening schedule is in a chart on the site someplace. It varies according to wind loads. unless your place is pretty sheltered, I would space them closer to 24" on center since you have the skip sheathing instead of ply sheathing.
The chart accually shows fasteners per sq ft which you jhave to scramble around and translate. I usually use a bit more than one per sq ft. I do doubles in each pan flat at the eaves. one more thought, I use the larger diqam screws with the 5/16" head - less likely to snap off under stress . And I dril the holes slightly larger than shank sixe to allow for thermal expansion of the sheets.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
zak,
We put 4 screws per run every other lathe run, one by each rib on SM and PBR panels. Every lathe on the ends gets screwed. Screw down ridge cap every other rib.
Run a string line for your eave overhang. If you figured your rake overhang right you won't have to do any thing special.
I have never seen the 1/4" epdm washers that are covered by steel go bad.
KK
Allright.. I've installed a lot of metal roofs so here's my 2 cents.
Sounds like the garage is a gable roof, so pre drilling is a big time saver and makes a cleaner job. Straight screw lines, no missed purlins--repair holes etc.. I always use an 1/8" bit...... you can drill at least 10 sheets at a time. 24" oc is the norm in my area, but can go as far as 60" using 26 gauge. Assuming your purlins/skip sheathing is square... use the first sheet as a gauge/drill guide for the rest. Use 1 screw on the flat next to each ridge...... that would be 3 or 4 screws per coarse depending on your metal profile.....R-Panel 3 screws... low profile 4 screws
Never pre drill your ridges... you should have some drill points for your stitch screws... careful not to over tighten and strip out... 2' oc for your seams. Use seam tape, it's cheap insurance. Don't use a drill motor to drive the screws or you'll strip out most of them... use a Tek gun or even a drywall screw shooter for your small project... should'nt heat up too much.
29 gauge is pretty flimsy (probably from a big box?) 26Gauge is the norm, so walking on it will dimple the metal pretty easy so use caution. On your bottom coarse (eave) use 1 screw on each side of every ridge to prevent any wind storm from getting its fingers under it. I always screw the ridge flashing at every point....and use closure strips (foam) if your worried about rain blowing in under the flashing.
Good luck.
Thanks. Good advice.
The roofing is 29 gauge (not from a big box, it's from the main roofing supplier in these parts, and it's the standard roofing panel sold around here- maybe because there's negligible hail/windstorms). I'll have to go back and get some stitch screws- I didn't realize I needed those until I looked at the site Piffin recomended. Sounds like I should be able to get'er done tomorrow.zak
"so it goes"
the type roof I have does not take stich screws.
What kind of profile you working with? Standing/ flat seam? interlocking panels?
One thing no one mentioned which is imperative is to use butyl rubber caulk (not silicon or latex!) at the laps between panels. If you don't, capillary action will suck water up into the lap joint and you'll get leaks, especially if the roof develops any ice dams.
Butyl caulk is usually sold by metal roofing suppliers; it comes in 300ml tubes. Best tool to use to apply it is a pneumatic caulking gun. I find squirting the bead into the underside of the upper panel's ridge channel to be the easiest.
As to the skip-sheathing/felt issue: If the option appeals to you, pull up the skip sheathing again and lay a deck of Black Joe on the trusses/rafters, then seal the joints with panel tape or strips of self-stick roofing membrane. Nail the skip sheathing on over the Black Joe and roof dircetly over that.
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
We use seam tape in my area.....1/2" x aprox. 1/8" thick. Goes on fast, less mess then tube prouducts.
With a pneumatic caulking gun, the caulk goes on so fast and easy it's hard to believe anything else could beat it. Stick the nozzle in the groove, pull the trigger, and run-don't-walk to the other end of the panel. Bingo. Done.
My guess is it's probably less expensive than tape, too. A tube of butyl runs me about a buck and a half and will do about 80-100 linear feet. The gun itself is a one-time investment, useful for all sorts of things; mine cost me about 60 bucks seven or eight years ago.
Once you get dialed in as to how big an opening to cut on the tube's nozzle and how much air pressure to run, it's easy as falling off a log.Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....