Metal Roofing

[Dennis H.]

Ok I tried to search for it but no luck so I figured I would start a new one.

What is the best way to put on metal roofing?
Put plywood down on the trusses then flet paper then the metal roofing and do I also put 1x4's on top of the flet paper as an air gap.
Or do I not put the plywood down at all but just use the 1x4's runing perpendicular to the trusses then the metal roofing on top of the 1x4's?

I heard somewhere that if it is just the metal roofing it will be raining inside because of the condensation forming on the under side of the metal roofing.

[tuckermtn]

first time I did strapping (1x4) on top of trusses. Lasted one season. Now have low grade ship-lap pine siding on top of trusses. If you have a white pine sawmill near you you can ask for seconds or my mill calls them "planer outs".

Works great. And its lighter in color so it seems like the place is brighter.

[northwoods_forestry]

You will probably want a full untreated wood deck on your rafters to prevent condensation on the metal roof from raining down on you. I would strongly advise not using plywood, felt, tar paper, OSB, or anything else that could drip nasty stuff down onto your operation and perhaps into your pans!

[Dennis H.]

Didn't really think about drippings from the plywood and tar paper. Thanks for the heads up.
I do like the idea of pine boards over the entire roof first.
Not sure if there is any sawmills around here that does pine, we are a heavy oak and ash around here. I will have to check.

Would poplar work just as good as pine? I have a few really straight tall poplar that I would love to get rid of and a few large white pine.

[lastwoodsman]

I put plywood down over the rafters and then the steel sheeting. I have a 2 x 6 and did not have any drops what so ever. I have read on here they recommend felt between the plywood and steel. I did not do this, time will tell if I should have.
Woodsman

[rookie]

poplar would work fine, just might be a little harder to nail than pine, never handled it green. you might have to predrill your wood.

[Flat Lander Sugaring]

well i hope im not goofing up but im just putting down strapping then metal, there is a metal roof out there with a felt coating on it to supposedly stop the dripping issue, i saw it on a horse barn i wired this summer

[danno]

I've just had metal over strapping for years with no trouble, except for the condensate drip. Not too bad with the full hood, but I'd imagine it would be raining inside of pans weren't covered.

[Gary R]

Dennis,

Up here the Amish are building sheds all day long. Everything is made out of Hemlock. They use 1X8 for purling's. Then they use what they call "double bubble", it is an insulation that is about 1/4" thick. It comes in a roll. Then the metal. I had them cover the entire roof with the 1X's. That way I don't have to look at the insulation. I have full hoods so I don't think there will be any condensation issue. What are you building?

[Dennis H.]

Gary I am working on plans for a bigger home from my evap!!:D

I want to do the outside with boards and battens. Putting a standing seam metal roof will make it stand out nicely.
I just wanted to do the roof right the 1st time. I never have worked with metal roofing before, it doesn't look or sound difficult to do.
My 1st idea was to lay plywood down then a moisture barrier then the roof, but I never thought about the few drippin's that may have some nasties from the plywood and moisture barrier.
So now I am leaning toward using pine boards under the entire metal roof, I have to find someone that will cut the boards for the walls so I might as well check about the boards fro the roof.

Hey Gary, I do want to get a look at your new sugarhouse sometime. I will need to run up to Dave Y's place to pick up a releaser at some point so I may have to swing over your way at the same time.

[SeanD]

Dennis,

You don't need to worry about anything dripping from the felt because it is between the plywood and the metal roof. It is not exposed to the inside. As far as anything dripping from the plywood, I wouldn't worry about it if you have a large enough cupola. I have plywood above a 2x6 and I didn't have anything dripping from the plywood itself. I did have one drip that came down from a rafter right next to the cupola door. There must have been something about the way the cold air hit the steam in that one spot. Of course it came down right where I sat to draw off - a pain in the arse, but nothing to redesign the roof for. Another factor is your wall height and air coming in to get a good updraft. If you use individual boards, you also have to keep in mind that you will have seams for the steam to find its way into, then you have water condensing between your metal roof and the boards (unless you join the seams). So, I think the benefits of using plywood outweigh the negatives.

Sean

[Gary R]

I forgot to mention that a poplar roof would look very nice. Plane the one side and ship lap. You'd have the best looking ceiling:D Boy, I love to spend someone Else's money. Give me a heads up on the visit. It would be great to catch up with you again.

[Father & Son]

Dennis,
I did the strapping (2x4s) over the trusses and the metal roofing. There are only certain places you can stand when boiling and not get dripped on but I didn't have hoods. Put up with this for seven years now and finally decided to order hoods. Hopefully this year I'll be able to stay dry and see inside the sugarhouse:)

[Sunday Rock Maple]

Poplar works great. I used it for the joists between the first and second floor on my garage. It takes a nail easy when green, very hard when dry.

[Maple Hobo]

Only a little sugar shack building experience, but 20 year in the Architecture and building industry as reference...

With metal roofing, If you could moisture and thermal barrier the inside it might prevent a lot of the condensation.
They make a standing seam metal roof system that stands off the mounting surface on clips and the insulation is about 3-6 inches deep under that between the clips. If you taped the seams on the bottom of the insulation with the silver foil duct tape (not grey tape) it would provide a moisture seal.

They have the insulated panels with a melamine layer on the bottom of them too.

MBCI is one of the places that makes an insulated metal panel with the insulation bonded directly to the back on the metal preventing both moisture and thermal problems.

To address the dripping trusses though... Scissor truss or vaulted style truss that slope twards the outside walls instead of flat bottomed like typical trusses might let the drips run to the walls instead of dripping in the pan or on your head.

It all depends on what you want to spend on a roof though.

[Thompson's Tree Farm]

My roof is made of solid one inch boars ( pine, popple, and hemlock....I have my own mill) and is covered with metal roofing. No drips and no issues with condensation.

[Maplewalnut]

Yes, the metal roofing is making the advantages for long years with the stability..... This advantages added this in the party to make the roof for the different industries and home as well.... contact the dealers for best offers and deals....!

What??????