sorry I need advice on leanto build!

[JB4310]

If I went under 4/12 I'd treat it as a flat roof and cover it with EPDM.

That's what I did on my very low pitch truck port. The overall is aprx 20' x 35' long. Glued it right to the plywood, got 1 seam in a 700 sq ft roof, Done!

 

[Couple of Achers]

I would have to say that the majority of the ag storage buildings are 4/12 pitch. Certain areas of the states may be less if they are not concerned with snow load. But up in the snow belt, 4/12 is common for ag buildings. But like others have suggested, make sure you are taking into consideration what the local code calls for min. snow load. Whether you get it inspected or not, you don't want the roof to crashing down on what you have just spend money to protect.

 

[Pops15]

4/12 pitch is plenty steep.
Have you thought about making the lean to narrower than the barn? That way you could make the lean to taller and still maintain your roof pitch.
10 foot centers are fine as long as you use a strong enough headers. Two 2 X12's with 1/2" plywood sandwiched between them are more than adequate for 10' spans. If you're worried about the snow load you could add another layer of plywood and a 3rd 2X12. You could also use LVL's or glue-lam beams and go 16' on center. That would give you better access.
6X6 posts are ok. If it was mine, I'd build laminated posts out of 2X6's.

 

[BryanM]

I think the gamble roof will be more expensive than adding on to the barn, so far as my figuring goes.

I was wondering if anyone has delt with menards on their manufactured beams? I have seen this in their adds that they have manufactured wood in different widths and lengths.

I think I will stick too the leanto plan but am going to have to talk too a lumber yard too see if I can find a width suitable for my needs. Then again I may have too be a little flexible in what I want in this situation.

 

[BryanM]

Actually, I can go higher on my gable walls I will have too put in some support posts instead of a ledger board and move the width in a bit. Just an idea.

 

[Pops15]

Actually, I can go higher on my gable walls I will have too put in some support posts instead of a ledger board and move the width in a bit. Just an idea.

If you use trusses you can actually support them on the bottom where they connect to the barn. The cost of trusses may end up being more than rafters & joists plus the extra support posts. Pick your poison.

 

[Pops15]

I was wondering if anyone has delt with menards on their manufactured beams? I have seen this in their adds that they have manufactured wood in different widths and lengths.

I've used manufactured beams but not from Menards. There are several types that would work for your application. I prefer dealing with lumber yards rather than box stores like Menards, but both will contact the manufacturer's engineering department so they can spec the right size beam for your application.
You can also use I joists for your rafters and go with a flatter pitch and a rubber roof. You'd need to split the span with a beam though. You could even go deeper than 18' with a set up like that. Years ago I built an addition that used 32' I joists sitting on a 6X16 laminated beam, and had another 6X16 laminated beam in the center of the addition to split the span. I used 3/4" T&G OSB with a rubber roof. The pitch was around 2 1/2-12.

 

[BungeeII]

I guess the rule is; "where there's a will there's a way".

Just keep pricing your options. Even with Pops helpful advice, I have to wonder if just simply extending the current roof-line isn't a more economical choice.

I went on the cheap with mine, but the 3.5/12 pitch limited our length.
10' high 20+ year old pole barn.
We completely stripped the gable end and nailed up osb.
Added a ledger from eave to eave.
Extension is about 9' out, with 2x8's on top of 4x6 posts 8' apart. (I'm pretty sure the spans are 2x6, 16" oc.
The siding on the sides is recycled from the end.
The siding on the end is scraps from vinyl that went on another barn, as well as old siding from a dairy barn that came down.

 

[JB4310]

That's a great looking shed Bungee,

But why is everyone fretting over the roof pitch, letting this minimum roof pitch criteria dictate the project? Is it just because that everyone is married to asphalt shingles or is it more for looks?

I made mine very low pitch ~1 ft in 20ft, 2x10 @ 16o/c ~18ft from ledger to header beam, triple 2x10 header, 6x6 posts at ~9 ft space.
Single ply rubber roof adds only ounces per sq ft, 1 seam, no leaks, not pretty but you can't see it anyway.

I needed to park truck with ladder rack under it, went as high as I could on existing structure (cottage used as shop) and my height requirement is what dictated the pitch.

Not saying go by my specs, but I've seen similar sized structures in my area built with 2x6 rafters and beams.

 

[Pops15]

But why is everyone fretting over the roof pitch, letting this minimum roof pitch criteria dictate the project? Is it just because that everyone is married to asphalt shingles or is it more for looks?

Aesthetics often come into play, but snow load is why we're concerned about pitch. You can often go with a much flatter pitch if your framing is beefy enough like I described a few posts ago.