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My husband built a toolshed 12 x 24 ft with a gable roof which has a 3 ft. rise. He's using the regular brown metal roofing sheets 3 x 8 ft, available from building stores. We have a problem - he says, I have it --- :-)
I hope the heck he's right..............

He read somewhere that there should be 2 inches left open next to the ridgeboard for ventilation and accordingly he made the rafters 8' 2".
I got all uptight and concerned and wanted the OSB to go all the way to the top - meeting the ridge board, and he complied because he didn't want to cut the rafters after they were put in place. He says if he STARTS the metal sheets 2 " below the ridge board everything will work out. I understand that but I'm concerned about the very minor overlap.

Our ridge board is a 2 x 6, so are the rafters. They are 24 " O.C.
How many inches MUST or SHOULD the metal ridge cap OVERLAP the roofing sheets?
We are in an area that gets quite a bit of snow ? Would 2 inches be enough?

ANYONE reading this tonight, early Saturday morning, please let us know, as he will put the metal sheets on tomorrow and I want to be sure it will be correct!
Thank you, Kate.
This is Kate. I posed the questions in this thread. For clarification purposes Saturday will be the day the metal sheets/roof goes on. It's Friday night where I live and that's why I called Saturday 'tomorrow'

I hope that neither you nor your husband have a problem!

What he originally read was probably related to installing a ridge vent along with the roof. Ridge venting, combined with soffit (overhang) vents for air intake, can be a very effective way to make sure that the structure or attic space does not have any extreme heat or moisture build up. (Please realize that this is nothing peculiar to metal roofing -- ridge venting is used with all types of roofing materials.

It sounds at this point like your ridge cover is not a vented system so you're not interested in the ventilation. If you are interested in the ventilation, then the OSB would have to be cut back the 2" at the ridge and we'll need to work on a slightly different ridge detail for you.

Now, if we're not worried about ridge venting, install one last layer of underlayment over the ridge -- laying half of the total width over each side of the ridge. Go ahead, then, and install the panels where they need to be so that they fall properly at the eave.

Ideally, I'd like to see about 3 - 4" of overlap with the ridge cover. (In other words, I'd like to see it extend 3 - 4" over the panels on both sides. From what you're saying,m you will just have 2"/

I assume you're using some sort of sealant or sealant tape between the ridge cover and the panels. Since we have only 2" of overlap, make sure that that sealant is well-installed and in full contact both with the roof panels and the ridge cover. It is also possible to install "Z-channel flashings" between the ribs on the metal panels to also help act as a waterbreak. These channels are used on hips also.

If you go to www.mtlsales.com and download their Product Specifications for 5V Crimp, you can see some pretty good drawings and details.

Now, as another option, you could always eventually change out your ridge cover for a wider cover. You'd probably have to buy some matching steel flat stock and have a sheet metal shop bend it for you.

I will be in my office Saturday morning until about 10 a.m. EST if you need to call me -- 1-800-543-8938 ext 201

Good luck. Regardless, install the panels where they need to be in relation to the eave. We can always change out the ridge cover for a wider cover later if that seems necessary.

I apologize for any typos in this. It's late (or early).
Hello Message Board Readers,

A great thank you to you, Todd, for answering on a Saturday Morning. We had not even known of a sealant and because of your reply we got some foam sections to fit between the roof cap and the panels and purchased some sealant. We also bought drip edges.

Well, if you are that helpful to a non-customer, your company must really treat its customers in a very personal and reliable fashion. That's hard to find nowadays. I think I found you on the net (www.classicroof.com ??)
I'll keep you updated to see how it all works out.

Again, my gratitude,
Thanks for the kind words. I hope that I was of some help. Please do not hesitate to contact me again.
Hello Todd and Others,

After your encouraging words the roof on the 24 x 12' toolshed/workshop was put on with GREAT :-) confidence yesterday, except for the ridge cap. Unfortunately there is a 70 % chance of rain today and the clouds are hanging over us already. My husband would prefer not to get started on the ridge cap at all and wait for a good day. If it would rain, could it be very damaging because of eventual moisture under the metal panels or is it nothing to worry about and how long after a rain must we wait before the ridge cap could be installed. Are there other considerations when one continues after a rain?

Presently there are 2 layers of 30# asphalt/roofing paper over the ridge. The metal panels come up to within 2 inches on each side.

By the way, we have metal roofing on our house since it was brand new in 1984. We just love it. Our subdivision neighbors have had much repair and some had their shingle roofs replaced completely. We just love the maintenance freedom of our roof.
Thanks again for any help.

Hi Kate,

Thanks for the update. Glad to hear that all went well with applying the panels.

Not sure whether both layers of 30# at the ridge are below or perhaps on top of the roof panels. It might not hurt to throw a layer over the top for now (secure it with some bricks or something) to help keep water from getting under the panels.

However, if water does get under the panels, one rain won't hurt anything and the 30# that is down will protect your decking so I would not worry about it. It will dry out -- you don't need to wait any length of time for that.

Glad to hear that the metal roof on the house is doing well.

Take care.


Hi All,

Well, the ridge cover was put on Monday Afternoon. The overlap was exactly 2 inches as predicted. Caulking was used as sealant between the ribs of the metal panels and the Z-channel flashing and then the cover was screwed on with 1 inch metal roof screws. I thought it should be larger screws to make contact with the OSB board underneath - but what do I know. Maybe, one morning I'll be going outside and find a piece of metal ridge cover on the ground. That's when I re-consider being married to an 'office guy'. But then who cares :-) ? - the roof on the house was done by an experienced builder. The tool shed qualifies as "masterpiece" - commonly called "custom build" - ha,ha, ha !!!

Thanks a lot for your assistance, Mr. Todd Miller,

How do I install ridge and valley caps for metal roofing?
How do I install ridge and valley caps for metal roofing?
This depends heavily upon the particular metal roof system you are installing. For the most part, though, the valley pan goes down first. It should extend out beyond your drip edge / starter. Depending upon the system and the accessory design, the ridge would either be installed next or after the panels are down.

Please feel free to contact me direct at tmiller@classicroof.com If you can give me details as to the type of system you're installing, then I can give you a better answer.
We are interested in knowing the distance and number of screws used to secure each 4x16" panel.

In addition, how much should each vertical panel overlap the next panel.
Can you provide more information as to the type of panel you're installing? I am not sure what 4x16" is referring to.


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