# Wood shed roof pitch.



## Haywire Haywood (Aug 2, 2009)

Is a 2' drop on 18' of roof enough? The splitter is just about done, now it's time to get that wood shed built before deer season. A lot of my help will disappear as soon as archery season opens.

Ian


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## Metals406 (Aug 2, 2009)

Haywire Haywood said:


> Is a 2' drop on 18' of roof enough? The splitter is just about done, now it's time to get that wood shed built before deer season. A lot of my help will disappear as soon as archery season opens.
> 
> Ian



Ian, thats pretty dang shallow, almost flat LOL. . . It equals a 1 5/16":12" pitch.


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## husky362 (Aug 2, 2009)

*what kind of roof*

If it's metal it should be ok , shingels or roll would need more pitch 

what kind of snow do you get, may have to add some supports if you receive a lot of snow just a thought


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## johninky (Aug 2, 2009)

How much snow do you get? Nearly flat roof+lots of snow=problems.


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## Haywire Haywood (Aug 2, 2009)

Metals406 said:


> Ian, thats pretty dang shallow, almost flat LOL. . . It equals a 1 5/16":12" pitch.



I take that as a no... LOL.

I'm going to be building one similar to the one you drew here but I want the short height in the back to be 7' and it's going to be 16 deep x 18 long. Long side open. 2 dividing walls for 3 compartments so I can be burning out of one, cutting green into one and have one full and seasoning for the next winter. My buddy has one that would have enough room for 2 seasons worth, but he's constantly having to either stack green in front of seasoned or constantly be moving wood around.

Ian


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## Haywire Haywood (Aug 2, 2009)

johninky said:


> How much snow do you get? Nearly flat roof+lots of snow=problems.



I'm in Kentucky with you... south of Lexington about 30 minutes. 

Metal roof.

Ian


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## MNGuns (Aug 2, 2009)

How about a gable roof with a 4/12 pitch.? Should be able to get premade trusses fairly cheap in this market.


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## Haywire Haywood (Aug 2, 2009)

While we're on the wood shed building subject.. 

4x4s in ground or anchored on top of concrete pads?

Ian


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## slinger (Aug 2, 2009)

If you are using ag -metal (29 gauge 3' wide) anything less than 2/12 is a no-no especially if there are valleys etc...

That said for a wood shed 1/12 will work as long as your structure will support loads (snow ice wind) and you can tolerate a few drips if you get a snow that melts slowly ...

You may want to use sealent at the overlaps - you can buy it from metal roll forming companies. It comes in rolls or caulking tubes - not silicone.

If you are concerned with leaks and will have a flat or low slope roof, use steel decking (like the roofs of Wal-mart/ Home Depot) it is generally 26 gauge or less and has flat and deeper ribs and also uses sealent for low slope apps.


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## slinger (Aug 2, 2009)

Haywire Haywood said:


> While we're on the wood shed building subject..
> 
> 4x4s in ground or anchored on top of concrete pads?
> 
> Ian



I don't like any wood in the ground. I like to mount decks and small outdoor buildings to sonotubes buried at least 36" or below frost in your area ( excluding the Great White North )

Usually for 4x4 anchorage to the sonotube I use a baseplate and connect to a galv. J bolt place in the concrete.


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## BlueRidgeMark (Aug 2, 2009)

TreeCo said:


> Mine are in cement 36 inches deep.



Why so deep, Dan? Do you really think there is frost that deep in your area? Or is this just the "belts AND suspenders" overkill that most of us love so much.


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## clearance (Aug 2, 2009)

slinger said:


> I don't like any wood in the ground. I like to mount decks and small outdoor buildings to sonotubes buried at least 36" or below frost in your area ( excluding the Great White North )
> 
> Usually for 4x4 anchorage to the sonotube I use a baseplate and connect to a galv. J bolt place in the concrete.



This is good advice.
How about the rafters Haywire? Less pitch, more load on them, there are span tables available, check it out.


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## MRNDAD (Aug 2, 2009)

I just posted some pics of a woodshed I just built in the "Pictures" forum. It might give ya some ideas to use as you build yours. Very basic construction. 4 pressure treated posts sunk in the ground...lattice for sidewalls...and a basic roof. 1 foot pitch in 8 feet of run. If you have any questions after ya look at the pictures...just let me know. oh yeah..I live in snowy New Hampshire and I am not the least bit concerned with snow loads on the roof.


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## Metals406 (Aug 2, 2009)

Haywire Haywood said:


> I take that as a no... LOL.
> 
> I'm going to be building one similar to the one you drew here but I want the short height in the back to be 7' and it's going to be 16 deep x 18 long. Long side open. 2 dividing walls for 3 compartments so I can be burning out of one, cutting green into one and have one full and seasoning for the next winter. My buddy has one that would have enough room for 2 seasons worth, but he's constantly having to either stack green in front of seasoned or constantly be moving wood around.
> 
> Ian



Ian, if you do 7' in the back, I'd do at least 10'-11' in the front. . . That will give you enough slope, and 11' isn't as high as you think. . . Imagine a basketball rim, or a tweed higher.

I would do concrete piers (Sonotube) or make your own square forms out of scrap wood. . . Leave 1' of tube out of the ground. When you finish the tops of your piers, taper the concrete sloped slightly to the edges (1/4" rise, per foot of run), so water/snow can't collect at the base of your posts. So on an 6"-8" pier, make the center 1/8"-3/16" higher.


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## 7sleeper (Aug 2, 2009)

TreeCo said:


> Mine are in cement 36 inches deep. Roof pitch is 2.25/12. Each bay is 8x8.
> 
> 8x40 wood shed with 30 inch eyebrow. Photo from two days ago.



Is that dog just taking a p€€?



7


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## Straightgrain (Aug 2, 2009)

If you sink the 4x4s into the ground, make sure they are .40 pressure treated or have a "GC" stamp.

I concur with all of what I seen in replies; If you have a snow-load of 25psi or more or a wind zone of +94MPH I would make 2x6s the smallest structural element, especially with the low pitch. 

Uplift, shear and snow load factors increase with low pitch open walled structures. No notching or boring the joists/rafters in the middle 1/3d of the span.

If you send me your "specs" I would be happy to run them on my struc calc program to check your spans (no strings haywaire). Safe spans for beams and knee braces can also be checked using my engineering references.

I dono about Kentucky; most states allow a homeowner to build "ag" buildings or "patios" under 200 Sqft (actual) without a structural permit.


Going to have lights or a slab in the structure?


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## Haywire Haywood (Aug 2, 2009)

It's going to be about 6.5' between uprights on the 18' side and 8' between uprights on the 16' side if I build it like I envision. I think I'll go 3' of drop over the 16' instead of just 2. If I build it like another I saw here, it'll have a 2x6 or 8 on each side of the uprights to put the rafters on.

Ian


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## Straightgrain (Aug 3, 2009)

Looks like 288 ft/2. (Thats 7,200 lbs of snow at 25lbs per square foot) Depending on how high your columns are (looks like they should be 6X6), the minimum angle/knee brace I would use on a structure that this size is 24". You should consider the roof assembly a diaphram and use diagonal "rat-runs" below the rafters to minimize the sheer. 
If you sink the footings or posts, consider going at least 12" below your frost depth. Ice can push up at 25,000lbs psi so I always double the size and depth of the footing. 
My "give-freely" offer (still stands)to check your loads, footings and general design still stand. PM me a sketch or at least a list of your specs.

Do you know your sizemic, snow and wind catagories? I ask because if you are spanning 16 or 18 feet between the front and back, you will need some serious rafters or open web truses with blocking the full depth to keep everythng from buckling under pressure..You using metal plate fasteners?


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## Haywire Haywood (Aug 3, 2009)

Heck, I don't know... most of what you said in that last post was Greek to me.. 

It's not going to be a 16' span though. Picture a grid of 12 uprights in a 4x3 pattern... There's going to be 2 supporting walls dividing the 18' length into 3 compartments, each measuring 6x16. The rafters would be supported in the middle, so the span between supports would be 8' on the 16' dimension and 6' on the 18' dimension.

Mud... it's not usually transparent.. LOL

Ian


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## wkpoor (Aug 3, 2009)

HayDude, about the shallowest pitch thats common in our area is 4/12 and for a shed that should be OK! Plus its easy to construct and work on. Find some shingles cheap and you will save big over steel unless you can find it cheap too.


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## Straightgrain (Aug 4, 2009)

I can look up your loads in my code book, I bought them, I might as well use them. 
With the interior walls supporting the rafters you should be OK. If you want, send me a sketch and I can explain what I mean. I went over your tributary areas, they will be OK with the interior walls. I would like to help with the nailing patterns of the interior walls. I like the 4/12 pitch and shingles idea on the last post. 12 feet high is your max height, I would use it.
2006 International Residential Code (IRC) Appendix "H"
Seizmic: there are 5 catagories in KY so I need to know what town you are in or cardinal location (N, W etc) 
Concrete weatherability is severe. PSI should be 2,500. (the bag stuff aint good enough for concrete exposed to weather). The frost depth is determined by the local jurisdiction.

Do you have powerpoint? I can get a sketch started and email it to you...No pressure, I don't want to elbow my way into your project. Just wanna help.
Your wind speed is 90 MPH. Do you have a lot of trees blocking the wind in your area (surface roughness)?
Ground snow load is 15 lbs per sq ft. Add 10 lbs per sq foot for materials=25 lbs per sq ft.
Termite is moderate to heavy. (the formosa termites nest 50 feet deep).
Interior walls: you should nail a 6/12 pattern, that is 6" spacing on the edges and 12" in the field. The plywood should be 1/2" or thicker. this will make an excelent interior brace panel. It will keep your structure from twisting under the forces. You going to anchor the interior walls to a slab? That would be awesome. If I were nailing the interior walls by hand, I would 8d common. if I was using my 23 degree nailer, I would slam in my 3" galv ringshanks.


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## Metals406 (Aug 4, 2009)

Straightgrain said:


> I can look up your loads in my code book, I bought them, I might as well use them.
> With the interior walls supporting the rafters you should be OK. If you want, send me a sketch and I can explain what I mean. I went over your tributary areas, they will be OK with the interior walls. I would like to help with the nailing patterns of the interior walls. I like the 4/12 pitch and shingles idea on the last post. 12 feet high is your max height, I would use it.
> 2006 International Residential Code (IRC) Appendix "H"
> Seizmic: there are 5 catagories in KY so I need to know what town you are in or cardinal location (N, W etc)
> ...



Great info Straightgrain. . . But it will all be lost (for the most part) on Ian LOL. I've talked "Carpenter speak" to him before, and it's over his head.

I think he's looking for something simple stupid, and if he doesn't have ordinances, or code that would apply to his project, not sure if he'll worry about engineering it. . . Well, nothing beyond "Yup, that looks strong". LOL

Although, it would be fun to mess with his head, and tell him about Exposure1 and Exposure2!


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## Haywire Haywood (Aug 4, 2009)

Boards stuck to other boards with nails and stuff. Waterproof stuff nailed to the high up boards to keep the rain out.

Now that's a plan I can wrap my noggin around...

Ian


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## modn (Aug 4, 2009)

wkpoor said:


> HayDude, about the shallowest pitch thats common in our area is 4/12 and for a shed that should be OK! Plus its easy to construct and work on. Find some shingles cheap and you will save big over steel unless you can find it cheap too.



Actually Steel is cheaper than shingles at this point. If you go unpainted, you should save some bigger coin. Although most metal companies will warranty down to 2/12 pitch, when installed properly with butyl caulk also used on seams, I would agree on the minimum 4/12 pitch. Steel will be there long after the shingles have deteriorated.


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## wkpoor (Aug 4, 2009)

You might be able to get older bundles of shingles off CL. I know where there is bundles upon bundles in black for free or real cheap. Brought home a couple for the coop last fall.


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