Need advice on Corrugated Roof

I've never done much roofing, and need some advice.

I'm having to replace the corrugated tin roof on my tractor shed and need to know the correct way to secure it. I was told to use either screws or nails with the rubber washers, and use them in the valleys of the corrugated tin. I had always thought they were supposed to go along the ridges for a good seal. He said that with the rubber washers, they will seal just fine in the valleys.

Using screws in the valleys of the corrugated tin would be the easiest way to do it. I just wonder if its commonly done that way.

What are the ways you all use to secure corrugated iron roofing?
Do you use screws or nails, and do you use the valleys or ridges?

I appreciate your suggestions.
Ronnie

We used screws in the valley's on strongpanel, 39" wide pole barn steel. only screwed it on top at the lap where it's double so it wouldn't compress. I you screw it on top the sheets will spread and it can gain or get crooked, you have to watch it!

Can you get some installation instructions from the manufacture?

I have seen it done both ways... nails in the "peaks", where they tend to spread the sheets or in the "valleys" where they will cause leaks as soon as there is ANY loosening of the nails or screws. NEITHER is without problems.

If you use nails, go through the rib. Screws go in the valleys. Nails w/ washers don't seal as well as the screws, so you need to keep them high (ribs).

Spend the extra money and buy the screws. Nicer look and friendlier to your thumb and forefinger of you nail holdin hand.

Tim K in NW Ohio ~ Who has a steel siding job this weekend.

Screws are better.

Both ways have been done, depends on the manufacturer.

The nails might not seal so well in the valley over time, I'd probably nail on the peaks.

Screws might compress & deform your peaks, I might place them in the valleys....

Pluses & minuses to both ways, I'd go with what the manufaturer of the tin says most of the time.

--->Paul

I usually put the nail with the rubber on the ridges just don't put the nail in too far. I would suggest using a drill to make a hole first. If the screws are sharp they may screw into the tin better. Stan

[color=darkred:501bb4479f]A decade ago the manufacturer's instructions were to attach through the ridges ... and then they all seemed to change to the flat or valley scenario for better longevity. Screws are definitely the way to go. I've used both.[/color:501bb4479f]

Use screws on the bottom. The nails will work themselves loose and sometime down the line they will have to be replaced with screws. Once the nails get loose you can pound them down and they won't stay. Just as well do it right the first time.
I have painted a lot of roofs that the paint has worn off and the tin that was nailed usually was loose where the screws were still tight.

I just finished an addition to my machine shed.I saved over 50%
by doing it myself.I'm old fashioned so used nails and nailed the
tin thru the ridges.

The builders do it both ways around here but most use screws.

Hex head screws with neoprene washers is the right way to do it. They hold six times better. I don't know where I read that. But they for sure hold a LOT better than nails. Tighten the screw just until the neoprene washer starts to bulge under the metal washer. Don't smush it down flat.

Roof screws in the flats. Just tight enough to slightly compress the neoprene washer.

Call the metal manufacturer - they'll be happy to give you advice. They'll also tell you about the warrantee - how to cut the metal (no electric saws) - purlin spacing - screw spacing - insulation board recommendations - the works.

The metal cutting - if you use an electric saw, it will sling hot particals out on the new metal and damage the paint, and also wreck the warrantee, not to mention your hearing. I didn't believe it (always the fool) but in about 10 years the damage shows up (rust).

Paul

Also - use a chalk line to keep your screws straight. Will make a neat job that you'll be proud of.

Paul

We"re not roofing pros, but we have always used the screws and always in the ridges not the valleys.

We pre-drill the hole and use the hex-head screws with the neoprene washers.

If you decide to use nails use double hot dipped galvanized ring shank nails w/neoprene washers. If you use screws use solid stainless steel screws, internal drive preferred, but they should be solid stainless steel, not stainless capped. With a stainless capped nail you'll eventually end up with a lot of the screws rusted with caps just sitting on them. You don't always get what you pay for but it's better to get the best. "Pay now or pay later."

sarge how did your get your message to print in red? bill m.

Like some others have said, we used screws with the gaskets and also put them in on the peaks (steel roof). The place we purchased it from said the instructions tell to place in the valleys, but over time any loss of seal will cause problems with leaks since all of the water for the whole roof is running down those valleys. It does not take much water at all to cause problems (one small hole can lead to trouble). We have had no problems with this method. Like others have said, using a line of some sort is a good idea to keep the screws in a straight line and looking good. Spend some time on your first piece so that you dont start straying one way or another as you work across! I am certainly not an expert roofer, but it worked well for us - good luck!

My 2 cents. Screws. Color coded for your tin with a drill point unless you predrill. Hex head with washers are the best. Get the right length depending upon going into the ridge or flat. Depending upon the underlayment, you probably want at least 3/4" or more of screw into your wood plus the height of your ridge. If screwing into 2 bys then why not screw 1 1/2" into the wood. Get a cheap electric impact wrench at harbor freight or use a good 18v driver/drill. Screws bought at Fastenal or whereever.

Depends on if the old style narrow spaced or new style wider spaced corrugations. Narrow stuff probably don't give you room to screw into the valley and have the washer seal it plus the narrow stuff had stronger ridges than the newer wide stuff(although a screw with washer into the ridge may not seal a heavy rain that fills the corrugations). Narrow stuff, I'd screw the ridges. Probably still do it for the wide stuff. It is also easier to lay a hand full of sheets upside down and predrill your holes into the ridge from the bottom. When predrilling, use two sheets layed out as a jig so you get all your lap holes to line up(easier said than done but start with a couple till you get it all lined up). Then use regular tip screws and your cordless drill and you don't have to fight making the screw hole and the screw slipping off to the side.

I've noticed the newer corrugated tin is a lighter guage than the old stuff. May be part of the reason why they say not to screw the ridges since they deform so easy then they look bad from the ground. With predrilling and not bearing down on the drill and knowing when to let off the gas, you should be all right.

I've got a barn to add on to. I'm going to go ahead and spend the extra bucks to go with colored metal used on steel buildings nowadays. Then I'll convert the rest as that galvanized tin rusts like it does. The new stuff with a large flat surface, they say to screw into the flats. I'm not convinced about screws into the flats (I think they are thinking about looks more than leakage)but I'd probably go for some overkill like pumping a tube of silicone into a flat pan and dipping the screws or coating the washers with it. I'd also bet that the steel building companies just can't make their crews keep from denting ridges so it's easier to let them screw the flats. (an owner can't complain and ask them to replace sheets if the don't drill into the ridges to begin with)(more of a quality control issue)

Now would be the time to put some roll type insulation down at the roof to stop any condensation from raining down on ya.

As an aside, I'm getting ready to do some vinyl siding and I'm going to use screws for that. Just hold a guage behind the screw and pull the trigger. When I pulled the old steel siding off, those roofing nails holding it popped off like nothing.I noticed the wind blew some corrugated tin off the older side of hte barn and those nails just pulled out.

Good luck.

Use screws.
I did more steel roofing with nails than I care to remember. What I do remember was that on every job you're sure to hit your thumb twice. The first time you take a little nick along side the thumbnail, you say @#!! it. The second time (the next day) you don't say anything, you just bit your tongue, wet you pants and try to stop the bleeding.

In 1978 we put a roof on a large barn for cows.
Panels started coming off in 2008. The neoprene
backed screws were used. The panels started
working loose after 30 years. Replaced roof in
2009 with same type fasteners on the flat part
of panel. I do not know which way is better, but
I won't be around in another 30 years to find out.

The debate on the screws on the ridge or in the valley:

I've done it both ways - couldn't force myself to put them in the valleys (or flats) for a long time. Finally tried it in the flats and liked it much better. No problems with leaks with either method, but I think it goes on quicker if screwed in the flats. The purlin is right under the metal - no flex, no slip off the ridge, and if the screw shooter is set right, no wrinkles in the metal. I set the screw by bumping the back of the shooter with the heel of my hand. Hard to do that on the ridge without the screw skipping off the side. The screw should go into the wood at least 1".

Just my experience - do it like you want to - it'll work either way.

Paul

i found out something new this week...i've built my fair share of pole barns and always used pressure treated wood for everything...some years back they changed the chemicals in the treated wood and it will attack galvanize panels and cold galv nails/screws...word from the roofing crew i talked to is plain southern yellow pine for nailers and hot dip or stainless fasteners.

FWIW i use screws in the valley...ustea use lead headed ring shank nails when they were affordable in the ridge.

Only lasted 30 years!!! What a crock! Seriously though, I would be happy with results like that, sounds like you were satisfied, too.

I've used both the nails and the screws. I have had an occasional problem with the nails working loose, but never a screw. Furthermore, I've gotten purple thumbs while driving the nails, but never the screws. I used to install the fasteners in the valleys, but now I use a punch to make a pilot hole in the ridge and screw there. I don't know if it makes any difference in the seal as I've only used screws in the ridges so far (not nails) and they have stayed tight.

Christopher

Yeah, the ACQ treated stuff caused a electrolysis between dissimilar metals. An area county had all their aluminum road signs screwed into those posts with steel lag screws. Ate a hole in the aluminum around the head of the bolt and their signs began falling down. Need a nylon or rubber separator between them now. Or the old CCA posts didn't seem to have that problem.

[size=24:d9963cfbfa][color=darkred:d9963cfbfa]Hey bill mart >>>>>> When you do a "reply" the font color option box is on the left side. Next to the other options.[/color:d9963cfbfa][/size:d9963cfbfa]

Hi Ronnie,

Always use screws on the ridge to keep leaks down.

Screwed in the valley guarantee's a leaking roof at some point in time.

The neoprene washer is to allow slight movement of the SM without pulling threw the screw head, during high winds.

Never use nails, period.

A standing seam roof is the best type of joint. 100% seal with less screws used but not on a corrugated roof. On a CR you will save approx 25% of screws but increase the labor time for standing seams.

Butyl caulk is your friend. The best caulking around-- bar none.

T_Bone<--- 45yrs Retired SheetMetal Worker

(quoted from post at 17:03:46 11/23/09) Hi Ronnie,

Always use screws on the ridge to keep leaks down.

Screwed in the valley guarantee's a leaking roof at some point in time.

The neoprene washer is to allow slight movement of the SM without pulling threw the screw head, during high winds.

Never use nails, period.

A standing seam roof is the best type of joint. 100% seal with less screws used but not on a corrugated roof. On a CR you will save approx 25% of screws but increase the labor time for standing seams.

Butyl caulk is your friend. The best caulking around-- bar none.

T_Bone<--- 45yrs Retired SheetMetal Worker

Click to expand...

Thanks, T_Bone.
Could you clear up a couple things for me?

What is a standing seam roof?
And are you suggesting to use Butyl caulking where the pieces of CR overlap?

Thanks,
Ronnie