Adding a lean-to

[Bourbon-Legend]

I’d like to add a 12’x40’ lean to to the back of a detached 20x40 garage. If I were to use 6x6 or even 8x8 posts and double up 2x10’s or 2x12’s what is the farthest span between posts I could go?

 

[Hot Rod Grampa]

You have to build to the code for your location. Snow load and up lift are only two of the considerations. Your local AHJ will be able to give you the correct numbers, as they will be the ones inspecting it. You can go longer with LVL's but all depends on what you are storing. 6' wide jeep or 22' wide combine. Build it to what you need for opening and size the headers for the span.

 

[GMCGarage]

I’d like to add a 12’x40’ lean to to the back of a detached 20x40 garage. If I were to use 6x6 or even 8x8 posts and double up 2x10’s or 2x12’s what is the farthest span between posts I could go?

I came up with 8'-0". Snow load and wind uplift are controlling. This is based on #2 SYP Lumber. IF you want to spend more, you could span more.

 

[Bourbon-Legend]

Thank you for the replies.

As for what I’m storing. A zero turn mower, UTV and my forge during the summer. During winter it will probably be empty for something temporary while working in out of the cold.

Could you elaborate on spend more? 5% or 200%? I am looking for minimal number of front support columns. I was hoping 10’ spacing but again not sure if it’s feasible vs cost of 8’ span

 

[joey1320]

Thank you for the replies.

As for what I’m storing. A zero turn mower, UTV and my forge during the summer. During winter it will probably be empty for something temporary while working in out of the cold.

Could you elaborate on spend more? 5% or 200%? I am looking for minimal number of front support columns. I was hoping 10’ spacing but again not sure if it’s feasible vs cost of 8’ span

I would contact your city/county building department and ask them what the minimum specs should be.

 

[86turbodsl]

i was able to go 16' span on my leanto with fabricated members. It's on my shop thread if you want to search.

 

[Bourbon-Legend]

Oh I’ll have to check that out as that could be a possibility. Thanks

 

[kylemac]

Using 2x10 or 12 LVLs you should be able to get a lot more span, have to spend a little more but will get you your span you need depending on which width you go with

 

[bad_idea]

The LVLs for (2)9x9 doors on my garage were $230 IIRC last summer. They are a 9"x1.75". LVLs cost a good bit more than 2x material. Call a lumber yard and get some prices. I do believe you can find span charts online. My building department would not give details on how to build, they said to look at the code and discuss with an engineer.

 

[Hot Rod Grampa]

The old rule of thumb for a span using double 2x was 1" in height for every foot span. So a 10' opening should have a minimum double 2x10 header. But snow load, if any, can change that. For peace of mind, an LVL can span more as a single, so in the long run is more cost effective. At 10' wide you could get anything in there that can legally go down the road.

 

[Bourbon-Legend]

Thanks for the info everyone. I will find out about building codes.


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[dreamingmuscle]

My pole barn has a 12'x40' lean-to. The poles are 6"x 6" on 10' spacing with a 2"x10" nailed to either side of the 6"x 6"

It's not supporting any real weight unless there is a snow load to worry about.

Glen

 

[Bourbon-Legend]

Thanks for the replies. I’m looking to build this in the fall and I am looking at something close to the one in the link below. I am thinking of going with 6x6 posts and then 2x12’s.

https://www.barntoolbox.com/pdffiles/12-lean-to-addition.pdf


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[JPinSTL]

I'm in MO. Not sure on codes. I added a leanto similar sized across the back of my pole barn. It was part of a roof tear off and raise, expansion, rebuild, mission creep project that is still not complete BUT I'm glad I did it!! I had a 24Dx40Lx8T and now have a 36Dx40Lx12T plus 10Dx40L leanto.

The existing building had trusses set on 10ft centers with 2x4 purlins on edge and was standing for 15yrs before I redid it.

I used 8x8 posts on 10ft centers
Doubled 2x10? or 2x12? band boards notched at the top of the post
2x10 rafters on 5ft centers using joist hangers
2x4 purlins laid flat on 2ft centers holding up the metal roofing

Warning!! A leanto across the back is handy but if you suffer from the horizontal surface affliction that I do it will soon be cluttered up. I do manage to keep one end clear for parking the tractor under.

 

[Bourbon-Legend]

I'm in MO. Not sure on codes. I added a leanto similar sized across the back of my pole barn. It was part of a roof tear off and raise, expansion, rebuild, mission creep project that is still not complete BUT I'm glad I did it!! I had a 24Dx40Lx8T and now have a 36Dx40Lx12T plus 10Dx40L leanto.



The existing building had trusses set on 10ft centers with 2x4 purlins on edge and was standing for 15yrs before I redid it.



I used 8x8 posts on 10ft centers

Doubled 2x10? or 2x12? band boards notched at the top of the post

2x10 rafters on 5ft centers using joist hangers

2x4 purlins laid flat on 2ft centers holding up the metal roofing



Warning!! A leanto across the back is handy but if you suffer from the horizontal surface affliction that I do it will soon be cluttered up. I do manage to keep one end clear for parking the tractor under.

Since that sounds very similar to what I am doing would you mind sharing a picture or two?
Thank you for the info!


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[Bourbon-Legend]

I was thinking something similar to this.


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[rsanter]

How about using steel posts and then a steel I beam. You could easily go the 10’ span you want and even go 20’ if you wanted.
Plus then you could put a trolly and chain hoist for unloading stuff

 

[Bourbon-Legend]

How about using steel posts and then a steel I beam. You could easily go the 10’ span you want and even go 20’ if you wanted.
Plus then you could put a trolly and chain hoist for unloading stuff

I priced it,unless you know something I don’t the, the price cost was 4 times the cost of wood.


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