Nice way to screw up a metal roof!

[Scott Patterson]

This roof was put on about a month ago according to the owner....

It has a total of 4 vent stacks and 9 attic static vent cans!

[Garry Sorrells]

Creative if nothing else.

Funny you posted this, Had a installation discussion just the other day. Topic was where to pace screws and why.

For the interested, some installation manuals:

Master Rib Roof Panel, Union Corrugating Co.
http://www.unioncorrugating.com/documents/MasterRib_InstallationManual.pdf

Look at pages 4 and 27

Best Buy Metals – Tuf Rib Roofing
http://www.bestbuymetals.com/pdf/tuff-rib-installation-guide.pdf

Fabral
http://www.fabral.com/wp-content/uploads/2013/02/bluebook.pdf

[Jerry Peck]

Garry,

Some require side lap tape and screws, some only require side lap tape, as shown by the three examples you posted.

Each manufacturer (to some extent) has their own fastening method, thus the manufacturer needs to be known before the fastening method can be deemed as incorrect.

Sure would be nice if they all came up with the same fastening method, wouldn't it?

[Garry Sorrells]

With only some very minor differences the installation method , for the same profile, is the same from my experience.

I can appreciate the concept that if you don't know the manufacture then you can not be sure of the installation that is acceptable. Though in the world of metal roofing and the flat rib profile the methods do not vary with a noticeable difference.

Please if you, anyone, can show a manufacture that specifies a different method please show me. I would love to see the variation from the majority.

Just for hoots a few more manufacture installation guides:

Metal Sales - Classic Rib
Resources Residential - Install Guides | Metal Sales Manufacturing Corporation (http://www.metalsales.us.com/residential/resources/install-guides)

McElroy Metal / Max-Rib
http://www.mcelroymetal.com/elements/files/MaxRibMesaInstallManual5-13.pdf

MBCI
http://www.mbci.com/pdf/design_tech_manuals/PBR-PBU%20Manual_February%202014_web.pdf

Central States Manufacturing
http://www.centralstatesmfg.com/wp-content/uploads/PanelLocGuide.pdf

[Jerry Peck]

The main difference you will find is at the lap.

Some require sealant tape, some recommend sealant tape, some require fasteners down through the lap to secure the top panel to the panel below, etc.

The ones which require the fasteners through the laps to hold the panels together can be installed from either end of the roof (no concern for which direction the prevailing wind is from), the ones which do not require the lap fasteners typically require "Panels should be installed with the sidelap facing away from the prevailing wind."

While the above may seem like a small difference, it really is a huge difference on correct installation and keeping the metal panels on during high winds (not even referring to what I usually refer to as high wind events - hurricanes ... just high winds).

If you see fasteners down through the laps, basically nothing to check, however, if you don't see fasteners down through the laps you should start considering which direction the prevailing wind is from.

If in doubt about the direction of the prevailing wind, you can either check the local airport (the runways face the direction of the prevailing wind, airports with crossing runways have the longer runway facing the prevailing wind) or check with your local weatherman as they should know which direction the prevailing wind is from.

This map may also help: Wind Map (http://hint.fm/wind/)

[Garry Sorrells]

Missed the point a little. What I was referring to was that the fasteners in the OP were in the tall ridge/lap and not on the flat of the panel. That tall ridge can be 5/8", 3/4, 1 1/4" typically. You see installations where screws were used in the tall ridge as apposed to the lowest flat section next to the tall ridge. When using screws all of the manufactures specify placement on the lowest flat next to the ridge. By example I refer to Union/MasterRib page #4

[Jerry Peck]

Missed the point a little. What I was referring to was that the fasteners in the OP were in the tall ridge/lap and not on the flat of the panel.

You missed the point a little. What I was referring to was that the fasteners in the top of the overlapping rib might not be wrong ... when in addition to the fasteners you are pointing out.

I was also expanding on your point by pointing out that not all manufacturers call for fasteners in the top of the overlapping, so not having fasteners in that rib is not always a defect, and that having fasteners in that rib is also not always a defect, and that when there are no fasteners in that rib --- the inspector needs to understand about prevailing winds.

You said "With only some very minor differences the installation method , for the same profile, is the same from my experience." and I was pointing out some of those minor differences. :)

You also said "Please if you, anyone, can show a manufacture that specifies a different method please show me. I would love to see the variation from the majority." so I was doing as you asked. :)

[Garry Sorrells]

You missed the point a little. What I was referring to was that the fasteners in the top of the overlapping rib might not be wrong ... when in addition to the fasteners you are pointing out............:)


Not every rib is overlapping. All screws in photo are in the top top of the rib and none on the flat next to ridge. Sorry I guess I should have been more explicit. Thought most would pick up on the differences between the OP picts and the manuals provided.

The 2 vents are wacked but the assumption was all would realize that. Many see screws in the ridge and think that is is how the manufacture instructs to install. Which was why I was asking for a manufacture link/reference from you. And I know, you have stated in the past that you have passed off on that installation method based on what was provided to you by someone on site so it must have been OK. Yet I have not been able to find such an installation guide to support that installation method. I can make an argument for screws in ridge and not on the flat next to the ridge, a discussion for a another day, but not supported by documentation. Which all seem to love/require documentation.

[John Williams]

The screws on the ribs are a holdover from the days when the roofing was attached with washered nails. The expansion and contraction of the roof caused the nails to loosen up and by placing them on the ribs they were less likely to leak.

[Jerry Peck]

Not every rib is overlapping. All screws in photo are in the top top of the rib and none on the flat next to ridge. Sorry I guess I should have been more explicit.

I, and I am sure that all others, are well aware that not every rib is overlapping, and that the photo shows fasteners into the top of each rib.

Seems that you are still missing my point - that not all are the same, and that one major difference is at the overlapping rib (which I keep pointing out "overlapping rib", not every rib, but you seem to have missed that to as you keep going back to every rib).

[Vern Heiler]

This roof was put on about a month ago according to the owner....

It has a total of 4 vent stacks and 9 attic static vent cans!
Interesting that none of the installation instructions have anything about roof vents (caps) and the plumbing boots are installed on flat roofs:confused:.

[Nate Bratton]

The screws on the ribs are a holdover from the days when the roofing was attached with washered nails. The expansion and contraction of the roof caused the nails to loosen up and by placing them on the ribs they were less likely to leak.

They are still installed with rubber washered screws and those washers eventually dry out and leak. My wife has been roofing for 25 years and only screws the metal down in the ribs. Nothing like having a 50+ year roofing material that leaks in 3-5 years because of sloppy (but approved) installation.

[melli macmillian]

They are still installed with rubber washered screws and those washers eventually dry out and leak. My wife has been roofing for 25 years and only screws the metal down in the ribs. Nothing like having a 50+ year roofing material that leaks in 3-5 years because of sloppy (but approved) installation.

Just curious, but are hidden fastener metal roofs not allowed down south? Up here, most everybody has moved away from exposed rib fasteners. Although we don't get the wind deep south folks get, we get our rainforest rain.
Has me wondering if hidden fastener roof are robust enough for high winds. Have to research that...
30537

[Rick Cantrell]

Just curious, but are hidden fastener metal roofs not allowed down south?

Allowed, at least around my area.

[Jerry Peck]

Allowed, but those roofs typically cost more to install ... so not as common on everyday buildings.

Is that photo an optical illusion or is that roof flat (low slope)?

[Jimmy Cope]

If you put them on the rib and over tighten you can strectch the panel and then have alignment problems. I always put the screws in the field (flat) and stitch the overlap by drilling a hole and puting in a special screw that is shorter and larger that the other. They make special rubber boots for metal panels (very pricey) but well worth it.

[Vern Heiler]

Allowed, but those roofs typically cost more to install ... so not as common on everyday buildings.

Is that photo an optical illusion or is that roof flat (low slope)?
I thought you would have computed the slope by the time of day and the length of the shadows:).

[Jerry Peck]

I thought you would have computed the slope by the time of day and the length of the shadows:).

It didn't calculate out to be a 3/12 or greater, more like a 1/12 of so ... so I had to ask for verification. :)

[Garry Sorrells]

Interesting that none of the installation instructions have anything about roof vents (caps) and the plumbing boots are installed on flat roofs:confused:.

Check out page # 27
Master Rib Roof Panel, Union Corrugating Co.
http://www.unioncorrugating.com/documents/MasterRib_InstallationManual.pdf

Page # 19
Fabral
http://www.fabral.com/wp-content/upl...2/bluebook.pdf (http://www.fabral.com/wp-content/uploads/2013/02/bluebook.pdf)

[Vern Heiler]

Check out page # 27
Master Rib Roof Panel, Union Corrugating Co.
http://www.unioncorrugating.com/documents/MasterRib_InstallationManual.pdf

Page # 19
Fabral
http://www.fabral.com/wp-content/upl...2/bluebook.pdf (http://www.fabral.com/wp-content/uploads/2013/02/bluebook.pdf)
I did not see anything about roof vent installation and the plumbing vent boots appear to be on a flat roof:confused:.

[Jerry Peck]

Check out page # 27
Master Rib Roof Panel, Union Corrugating Co.
http://www.unioncorrugating.com/documents/MasterRib_InstallationManual.pdf

Slope of roof is not indicated for this one.



Page # 19
Fabral
http://www.fabral.com/wp-content/upl...2/bluebook.pdf (http://www.fabral.com/wp-content/uploads/2013/02/bluebook.pdf)

See page 46 in this one.

Slope of roof is not indicated for this one either.

[Garry Sorrells]

Jerry,
Pitch is earlier in PDF


Fabral
Page. 8

Roof Pitch
The metal roofing panels shown in this manual require a minimum slope of 2½” per foot to ensure proper drainage. Refer to the rain-carrying table in this booklet for the maximum allowable panel length per slope that will provide adequate drainage. For longer slopes and lower roof pitches, contact FABRAL for other suitable profile


MasterRib
Page. 5

Roofing
Slopes of less than 3” on 12” are not recommended.
For slopes less than 3:12, apply 3/8“

Page. 8 See PDF for picts
Pipe Boot MF3 (Various sizes, heat treated & retro fit also available)


Page. 27 See PDF for picts
Pipe Flashing
Cut pipe flashing along the pipe diameter marking. Apply tube sealant to the underside of the pipe flashing.

Slide pipe flashing down over the pipe.
Press the pipe flashing into contours of panel configuration and fasten to the MasterRib® panel with self-sealing stitch screws. Apply additional sealant around base if desired.


Page 21
Vented Ridge

[Garry Sorrells]

I did not see anything about roof vent installation and the plumbing vent boots appear to be on a flat roof:confused:.

Can you rephrase the question. Roof vent installation, meaning attic air or plumbing pipe?

Did the my previous post answer question?

[Vern Heiler]

Can you rephrase the question. Roof vent installation, meaning attic air or plumbing pipe?

Did the my previous post answer question?
Roof vents are for attic air, plumbing vent boots are for plumbing. There is nothing about how to install a roof (attic) vent, the hole in the roof with a cap, and the vent boot installation diagrams are pictured on flat or low slop roofs.

[Garry Sorrells]

Roof vents are for attic air, plumbing vent boots are for plumbing. There is nothing about how to install a roof (attic) vent, the hole in the roof with a cap, and the vent boot installation diagrams are pictured on flat or low slop roofs.

Sorry, Installation for other than Ridge vent and Plumbing Boot flashing is not in the instructions for the roof panels.

The roof vent like this is not in the roof install PDF. You have to go to the vents manufacture to get install instructions.
http://www.faqs.org/patents/img/20120073239_01.png

As far as the vent boot installation diagram being shown on flat or low slope, I think it is just how it may appears in the diagram but not as they intended it. You don't use metal roofing on flat or really low slope roofs. You can get by on some low slope situations but you are going against manufacture suggestions and you have to be a little adaptive/creative with the installation for it to work.

[Vern Heiler]

Sorry, Installation for other than Ridge vent and Plumbing Boot flashing is not in the instructions for the roof panels.

The roof vent like this is not in the roof install PDF. You have to go to the vents manufacture to get install instructions.
http://www.faqs.org/patents/img/20120073239_01.png

As far as the vent boot installation diagram being shown on flat or low slope, I think it is just how it may appears in the diagram but not as they intended it. You don't use metal roofing on flat or really low slope roofs. You can get by on some low slope situations but you are going against manufacture suggestions and you have to be a little adaptive/creative with the installation for it to work.
Thanks for the research Gary.

[Garry Sorrells]

Vern,
Your welcome.
Sometimes it is difficult to find answers unless you have had a background/experience in an area. It just makes understand which rock to turn over easier.

It is a little strange that metal roof manufactures don't have more detailed specifications in their manuals. But there is a lot of materials that are used with the roofing and many ways to make it work.

[Jim Luttrall]

If in doubt about the direction of the prevailing wind, you can either check the local airport (the runways face the direction of the prevailing wind, airports with crossing runways have the longer runway facing the prevailing wind) or check with your local weatherman as they should know which direction the prevailing wind is from.

This map may also help: Wind Map (http://hint.fm/wind/)

Prevailing wind and wind with rain are two totally separate directions here, and I assume in other locations also. While we get much of our prevailing wind from the south along with lots of the humidity and clouds out of the Gulf of Mexico, most of our violent wind and rain events originate out of the north west. So we get little rain or even high winds that impact the south face of a house, lots of water penetration around unprotected doors and wind damage to roofs are common on the north to west faces. So for our area installing the laps for the prevailing wind would be counter productive when considering the prevailing rain and high wind events.
Of course I know Jerry knows this but for the rest of the forum out there, take your own weather patterns into account for the finer points of roof construction.

[Jerry Peck]

Jim L.,

The prevailing wind is not relevant to wind driven rain as metal roofs are without sealed seams (think soldered seams) are not considered watertight (that's why they have weep channels, etc) - the prevailing wind is considered with regard to the direction of the lap to reduce the likelihood of the metal panels getting higher pressure wind under them and lifting the panel edges ... lift one panel edge and the entire roof can peel off like opening a can.