Contractor Talk - Professional Construction and Remodeling Forum banner
1 - 20 of 55 Posts

·
Registered
Joined
·
30 Posts
Discussion Starter · #1 ·
What is your prefered location to put screws in the rib or fla
Is their a better alternative to 30pd felt as underlayment?
And most imrtantly why dont somebody come up with a better way to tuck a
Ridge cap where two roofs meet
 

·
Registered
Joined
·
2,891 Posts
What is your prefered location to put screws in the rib or fla
Is their a better alternative to 30pd felt as underlayment?
And most imrtantly why dont somebody come up with a better way to tuck a
Ridge cap where two roofs meet
I say do whatever the manufacture recommends, others disagree.

Some guys are using synthetic.
 

·
Registered
Butcher of wood and metal
Joined
·
6,838 Posts
Personally I use synthetic under all my steel roof with Ice and water in the valleys. With the type of steel roof today most all get screwed in the flat up close to the rib. The old lead headed nails , don't know of anyone even using them anymore. As with most things it is all in the flashing that makes or brakes a job.
 

·
Registered
Joined
·
9,883 Posts
Common sense will tell you, water runs in the low areas, hence, we screw the ribs. As I have pointed out before, and some strongly disagree, the manufacturers do not actually test anything....
 

·
We Put Poles In Holes
Joined
·
206 Posts
Synthetic underlayment with screws in the flat and stitch screws in the rib. Both of the steel manufacturers that I use recommend this.
And personally I will never fasten the roof down through the rib. Have seen several jobs where the screw had deteriorated in that 3/4" space to the point where I would snap them off when trying to remove them. Granted these were in agricultural applications with no underlayment and lots of condensation and ammonia buildup.
 

·
diplomat
Joined
·
5,292 Posts
Common sense will tell you, water runs in the low areas, hence, we screw the ribs. As I have pointed out before, and some strongly disagree, the manufacturers do not actually test anything....
If we're talking light gauge ribbed steel, which is my only experience, water attaches itself to the screws and epdm washers and stays there until it dries, whether it's on the ribs or in the flats. We must rely on the epdm seal either way, so I follow the directions and fasten in the flats next to the big ribs.
 

Attachments

·
Registered
Joined
·
9,883 Posts
Do as you wish. I know what my experience has been, and there is strong opposition because the structural testing by Underwriters Labs says otherwise. Uh huh.

We have done many, many roofs where the length of the panels are 30 feet and more, and if screwed down tight on the flats, then the panel cannot expand and contract with temperature variations. The screws can flex a little with a 3/4 inch exposure. We have never experienced a problem, ever, and I have been doing metal roofs for 15 years now.....and it hasn't been many years since there was 20 guys on this forum for every one who installs metal complaining about metal roofs and saying they would never put barn metal on a house.

So if water attaches itself to the screw head, and stays until it dries, I will still stick with conventional thought...and defy the premise that "manufacturers recommend" the screw placement dictated by UL by screwing in the ribs, and no lap screws needed. Only thing you need is a sure touch on the trigger and don't over drive. Positive is there are way fewer tear outs of the sealing washer...but then, who is looking?
 

·
Registered
Joined
·
30 Posts
Discussion Starter · #10 ·
I switched to the ribs a couple years ago after doing a low pitch roof
The water sit around screws. Asked my supplier and they said either way is fine.
Ice and water plus synthetics as stated by others sounds like a really good idea!
Maybe especially around these darn ridge cap intersections. I havent had a leak yet but around cap intrscns seems like a good place for one!
 

·
Registered
Joined
·
301 Posts
Ok so I read all these posts. I have been a metal roofer for 20 years I have installed almost every style of metal panel out there. The answer isn't as simple as everyone here states. We need more information. Is it raised rib, 5V or ......? Most agricultural panels require screws in the flat but their are a few that require it in the rib. As for depending on the washer a light touch on the trigger is very important. I never use tar paper anymore on either metal or shingles. It just doesn't make sense to use a product that will dry out over time. I prefer Titanium UDL for all my roofing projects. It carries it's own warranty when installed properly and you can leave it exposed for extended periods of time without worry. I also recommend plastic cap nails no matter what underlayment you use. Not all synthetics are created equal. For instance Rhino says right on it for use under shingles only.
Pole barns and houses need to be installed differently due to the different types of movement in each structure.

You can make metal roofer a shinglers but you can never make a shinglers a metal roofer.
 

·
Registered
Joined
·
1,934 Posts
We don't install pole barn steel on houses. It is for pole barns. Screws go on the flat. Screws on the rib can dent the steel if the are too tight, making small areas for water to pond on every screw. Not a real good reason, but in time you could have a leak, rust, etc..

We have been replacing steel on pole barns lately because of hail. Not a great alternative to shingles, IMO.
 

·
Registered
Butcher of wood and metal
Joined
·
6,838 Posts
Ok so I read all these posts. I have been a metal roofer for 20 years I have installed almost every style of metal panel out there. The answer isn't as simple as everyone here states. We need more information. Is it raised rib, 5V or ......? Most agricultural panels require screws in the flat but their are a few that require it in the rib. As for depending on the washer a light touch on the trigger is very important. I never use tar paper anymore on either metal or shingles. It just doesn't make sense to use a product that will dry out over time. I prefer Titanium UDL for all my roofing projects. It carries it's own warranty when installed properly and you can leave it exposed for extended periods of time without worry. I also recommend plastic cap nails no matter what underlayment you use. Not all synthetics are created equal. For instance Rhino says right on it for use under shingles only.
Pole barns and houses need to be installed differently due to the different types of movement in each structure.

You can make metal roofer a shinglers but you can never make a shinglers a metal roofer.


In using plastic cap nails do you have any problem with the caps showing through the metal?

I have seen some of the metal roofs shinglers have put on. :rolleyes:
 

·
Registered
Butcher of wood and metal
Joined
·
6,838 Posts
We don't install pole barn steel on houses. It is for pole barns. Screws go on the flat. Screws on the rib can dent the steel if the are too tight, making small areas for water to pond on every screw. Not a real good reason, but in time you could have a leak, rust, etc..

We have been replacing steel on pole barns lately because of hail. Not a great alternative to shingles, IMO.
From what I have seen here , if hail ruins steel roofs then the shingled ones are gone too.
 

·
Registered
Joined
·
1,934 Posts
From what I have seen here , if hail ruins steel roofs then the shingled ones are gone too.
Sometimes ya. Shingles are a little cheaper though and work in transitions much better.

We just replaced a pole barn steel roof twice in one year. The house (on same property) with shingles didn't have damage. CT Landmark's. Some fascia's, soffit, and metal roofs. Anything metal was damaged aside from our steel vents on the house.
 

·
Registered
Joined
·
30 Posts
Discussion Starter · #19 ·
In using plastic cap nails do you have any problem with the caps showing through the metal?

I have seen some of the metal roofs shinglers have put on. :rolleyes:
Yes I have had to start pulling the caps off as I go to keep them from showing through the metal.
 

·
Registered
Joined
·
301 Posts
In using plastic cap nails do you have any problem with the caps showing through the metal?

I have seen some of the metal roofs shinglers have put on. :rolleyes:
I have never had any issues with the caps showing through. It creates a slight air space between the metal and the roof deck. This allows any condensation dissipate.
 
1 - 20 of 55 Posts
Top