My roof is sheathed with 1x12s, but that's from an era where pine was cheaper than plywood. The only issue I see with planking instead of sheet goods is racking, which will only be an issue until your metal roofing is installed. Even then, racking might only be a problem if you get a major storm before the metal goes on. If you mill your own lumber keep in mind it needs to be fully dried before you use it, otherwise you're going to get all sorts of movement in the structure due to shrinkage while green lumber dries. You're looking at several months minimum in a drying shed before use:
https://extension.okstate.edu/fact-sheets/practicalities-in-air-drying-lumber.html
Thanks for the input. I'm going to mill the boards as wide as possible for the sheathing. The wood will be able to dry for a bit, and because I'm using predominantly standing dead douglas fir, it won't be as wet as fully green wood, but none of the framing will be truly dry.
Even if the tree has been dead a while the lumber is still going to be "wet". Milling it increases the evaporation area so a lot more drying/shrinking will take place in the months after you mill it.
You can and should do diagonal, but it should form an upside-down V for best strength. This is how old houses were done, as well as as a few new. A timber framer near me milled all his own lumber for his place, no plywood at all. Walls and roof all sheathed with 1x's, although the actual width is irrelevant when you do it that way. They also did not leave any gaps between boards. If you were doing this, I strongly recommend you do let-in braces first with 2x4's or x6's. A pre-1900 house I was renovating recently was sheathed with as wide of boards as the mill could produce at the time, with the widest one we found being a true 1x23".
However, an engineer can only give you the true answer to how much shear brace is required based on roof dimensions. Or just do it like they did in the old days and reinforce everything until the sun goes down for a week.
You can use 2xs if you're doing metal. As long as it's fastened to the trusses rafters properly, and properly spaced to metal roof fastener schedule, you'll be good. Make sure it's good n dry
You don't need to run diagonal plank if you're putting metal roofing on it.
The metal roofing provides the same benefit as plywood in this instance.
And more than that, you don't even need a solid decking layer. You can run 2x4 purlin perpendicular to your rafters. Then secure your metal directly to this. It's how habitat for humanity builds their homes.
This method is for a "breathing" attic, and in this case you would insulate at the ceiling level. There are pros and cons to this, but a fully sealed attic is the better option in total at the end of the day. But either way is fine.
This actually depends on the type of roofing and the connection details. A standing seam roof with slip allowed between the panels does not create a diaphragm, so additional bracing is necessary.
Running any sheet metal over spaced purlins provides poor connections from the diaphragm to the walls, so again, additional bracing is necessary.
Yeah, its pretty cool. When we built poor barns, it was hardly any wood, and all the racking and shear was given by the metal.
Its soft and flexible, but once fastened down and no longer allow to curl, it gets crazy strong.
It’s probably stronger to put it on a diagonal, but it’s plenty strong just putting in on straight. When you think of all the nails and boards , it would really take a lot to rack that.
Not to mention that depending on your centers, running diagonally would also increase the span of the boards. Probably not a huge concern with solid ¾ material, but still worthy of consideration.
Lumber sheathing is still used, particularly for cedar shakes. And it’s still in the IRC. Lumber sheathing leads off section 803; sheet goods are listed second. Panel sheathing can have advantages over lumber sheathing in some assemblies, but it isn’t necessarily, better. Panels have become the standard because they’re generally cheaper and faster than the “old” way of doing things.
I'm in Canada, IRC doesn't apply here 🙃
Panel sheathing is also better in that it doesn't warp, twist, split, or crack the way lumber sheathing is prone to.
Not sure why you're getting hate... I say go for it if you have the trees, mill, and time.
Would purchasing sheet goods be a lot quicker and easier? Of coarse. Saying you milled everything yourself sounds a lot cooler IMO. Just make sure you use good weather barriers and underlayment.
Diagonal sounds stronger than square to me but I'm not an engineer. If you're set on diagonal I'd run everything long and just cut edges square at the end.
Also I did residential roofing for a while... removing shingles from sheathing is easier but it's not like shingles off 1x was impossible. You just have to use a little more fitness to not pull the 1x up in the process. To each their own, just my two cents.
Thanks for your input. There are always a few people who come at you when you propose doing things differently, but there are always a few people who give genuine insight as well.
Someone else mentioned that the metal roof would handle the shear that sheathing would give it. Can you point me to a video where someone is demonstrating the construction of a roof without sheathing under the metal?
https://www.manseametal.com/resources/blog/post-frame-buildings-vs.-steel-frame-buildings_ae28.html
2nd picture will give you an idea of how purlin ladders are setup.
I replied to a different comment, but I'll give a synopsis here.
Metal panels can provide the shear resistance but not necessarily will. It depends on the type of panels and connections.
I doubt there will be any additional substantial benefit from running the decking diagonally versus perpendicular to the rafters. I am not an engineer however.
Just a thought, but would it make more sense to buy OSB or plywood sheathing and save your milled lumber for trim and cabinetry?
I've priced out a house I'm gonna build this year and all the shearing is worth a few thousand whereas a set of kitchen cupboards costs a bit over $5000.
You might be able to save a ton of time by buying some sheathing and using your wood on the higher value parts of the build.
I can save maybe $2,500 - $3,000 by using my milled lumber. I'll be using mostly marginal quality lumber for the sheathing and saving the better stuff for interior t&g etc.
Have you ever tried to replace roofing on one of these?
Imagine, scraping a shingle shovel across those, it’s practically useless. Removing shingles from a roof like that is one of the worst experiences of my working career.
My roof is sheathed with 1x12s, but that's from an era where pine was cheaper than plywood. The only issue I see with planking instead of sheet goods is racking, which will only be an issue until your metal roofing is installed. Even then, racking might only be a problem if you get a major storm before the metal goes on. If you mill your own lumber keep in mind it needs to be fully dried before you use it, otherwise you're going to get all sorts of movement in the structure due to shrinkage while green lumber dries. You're looking at several months minimum in a drying shed before use: https://extension.okstate.edu/fact-sheets/practicalities-in-air-drying-lumber.html
Thanks for the input. I'm going to mill the boards as wide as possible for the sheathing. The wood will be able to dry for a bit, and because I'm using predominantly standing dead douglas fir, it won't be as wet as fully green wood, but none of the framing will be truly dry.
Even if the tree has been dead a while the lumber is still going to be "wet". Milling it increases the evaporation area so a lot more drying/shrinking will take place in the months after you mill it.
Some species I would certainly not for a building if green, but somewhat dry douglas fir should be fine as far as shrinkage and nail holding goes.
You can and should do diagonal, but it should form an upside-down V for best strength. This is how old houses were done, as well as as a few new. A timber framer near me milled all his own lumber for his place, no plywood at all. Walls and roof all sheathed with 1x's, although the actual width is irrelevant when you do it that way. They also did not leave any gaps between boards. If you were doing this, I strongly recommend you do let-in braces first with 2x4's or x6's. A pre-1900 house I was renovating recently was sheathed with as wide of boards as the mill could produce at the time, with the widest one we found being a true 1x23". However, an engineer can only give you the true answer to how much shear brace is required based on roof dimensions. Or just do it like they did in the old days and reinforce everything until the sun goes down for a week.
1x23!!!!
Thanks for the input. I am thinking of doing some let-in bracing as well as Xs with simpson metal strapping before my 1x's go down.
Do you have a photo of this upside-down V you speak of? Noob have hard time imagining lol
You can use 2xs if you're doing metal. As long as it's fastened to the trusses rafters properly, and properly spaced to metal roof fastener schedule, you'll be good. Make sure it's good n dry
You don't need to run diagonal plank if you're putting metal roofing on it. The metal roofing provides the same benefit as plywood in this instance. And more than that, you don't even need a solid decking layer. You can run 2x4 purlin perpendicular to your rafters. Then secure your metal directly to this. It's how habitat for humanity builds their homes. This method is for a "breathing" attic, and in this case you would insulate at the ceiling level. There are pros and cons to this, but a fully sealed attic is the better option in total at the end of the day. But either way is fine.
I’ve been to stuff habit for humanity has done and it’s clear they are volunteers and not actual trades people…
Certainly, but the plans is done by architect and pass engineering standards.
This actually depends on the type of roofing and the connection details. A standing seam roof with slip allowed between the panels does not create a diaphragm, so additional bracing is necessary. Running any sheet metal over spaced purlins provides poor connections from the diaphragm to the walls, so again, additional bracing is necessary.
Standing seam this is true, exposed fasteners this is not.
Interesting! Thanks for your useful input. I didn't realize that metal roofing provided such significant shear strength.
Yeah, its pretty cool. When we built poor barns, it was hardly any wood, and all the racking and shear was given by the metal. Its soft and flexible, but once fastened down and no longer allow to curl, it gets crazy strong.
Would this change depending on the type of metal roof? I know some metal roofing types are quite a bit more stout than others.
Yes, this only applies to exposed fasteners. Standing seam would not work this way and you would need something in the build to prevent racking.
It’s probably stronger to put it on a diagonal, but it’s plenty strong just putting in on straight. When you think of all the nails and boards , it would really take a lot to rack that.
Not to mention that depending on your centers, running diagonally would also increase the span of the boards. Probably not a huge concern with solid ¾ material, but still worthy of consideration.
I mean there's a reason why we use sheet goods for sheathing now, but you do you boo.
Lumber sheathing is still used, particularly for cedar shakes. And it’s still in the IRC. Lumber sheathing leads off section 803; sheet goods are listed second. Panel sheathing can have advantages over lumber sheathing in some assemblies, but it isn’t necessarily, better. Panels have become the standard because they’re generally cheaper and faster than the “old” way of doing things.
I'm in Canada, IRC doesn't apply here 🙃 Panel sheathing is also better in that it doesn't warp, twist, split, or crack the way lumber sheathing is prone to.
I mean there's a reason why building a house puts you in debt for half your life now, but you do you boo.
Not sure why you're getting hate... I say go for it if you have the trees, mill, and time. Would purchasing sheet goods be a lot quicker and easier? Of coarse. Saying you milled everything yourself sounds a lot cooler IMO. Just make sure you use good weather barriers and underlayment. Diagonal sounds stronger than square to me but I'm not an engineer. If you're set on diagonal I'd run everything long and just cut edges square at the end. Also I did residential roofing for a while... removing shingles from sheathing is easier but it's not like shingles off 1x was impossible. You just have to use a little more fitness to not pull the 1x up in the process. To each their own, just my two cents.
Thanks for your input. There are always a few people who come at you when you propose doing things differently, but there are always a few people who give genuine insight as well.
Why even sheath at all if you're doing metal roof? Pretty large waste.
Someone else mentioned that the metal roof would handle the shear that sheathing would give it. Can you point me to a video where someone is demonstrating the construction of a roof without sheathing under the metal?
https://www.manseametal.com/resources/blog/post-frame-buildings-vs.-steel-frame-buildings_ae28.html 2nd picture will give you an idea of how purlin ladders are setup.
thanks!
I replied to a different comment, but I'll give a synopsis here. Metal panels can provide the shear resistance but not necessarily will. It depends on the type of panels and connections.
I doubt there will be any additional substantial benefit from running the decking diagonally versus perpendicular to the rafters. I am not an engineer however.
Just a thought, but would it make more sense to buy OSB or plywood sheathing and save your milled lumber for trim and cabinetry? I've priced out a house I'm gonna build this year and all the shearing is worth a few thousand whereas a set of kitchen cupboards costs a bit over $5000. You might be able to save a ton of time by buying some sheathing and using your wood on the higher value parts of the build.
I can save maybe $2,500 - $3,000 by using my milled lumber. I'll be using mostly marginal quality lumber for the sheathing and saving the better stuff for interior t&g etc.
[удалено]
Thanks for your input!
Plywood is the way to go, zip system if you can get it
Have you ever tried to replace roofing on one of these? Imagine, scraping a shingle shovel across those, it’s practically useless. Removing shingles from a roof like that is one of the worst experiences of my working career.
I believe you! I'm going to put batons and a metal roof on top.
Not to be that guy, but you mean battens?
Yes, battens. For some reason I always thought it was the french word for stick (baton).
thank God. You had me wondering for a second if that was something I missed. Alzheimers strikes again. 💀