Attaching a lean-to to my shop

twoslo4five0 said:

what slope did you end up with? I think I could have got away with less on mine but better safe than sorry. What will the roofing be attached to (size wood for rafters). How much snow do you get there?

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Slope - Whatever it ends up with
Rafters - 2x6
Snow - very little, very rarely.

good deal

A lot depends on what type of roofing you will be using, how big it will be, and whether you plan on using OSB and tar paper under the tin. I just finished with two pole barns, a 24x48' and a 24x36', and I am adding 8' extensions to the rear of each. Both are sloped around 1.5-2' from front to rear, but I can't remember the exact amount.

I've started on the 8' extension to the 24x36', and I'll have to post a few pics. I didn't go the full 36' width, and ended up adding 8x24' to the rear. I used 2x4s on 16" centers as my rafters, using three 4x4 posts to hold up the addition. I won't be using OSB & tar paper under the tin, have simply run 1x4" furring strips every couple feet to screw the tin to. The roofing I am using is 29ga 5v tin, and the roof will be plenty strong.

I'll post some pics as soon as I can, as it will show you what I am doing much better than me trying to describe it.

My plan was to just use the 1x3 or 1x4 furring strips across the 2x6 joists and skin on top of that.

BTW, posts are 14' from the building, so I should end up with approx. 15x30 worth of covered area to part stuff under.

You could use some ridge cap and turn it upside down and screw it to the wall at the top of the lean to. This will seal the carport roof to the building.

Or if you have a sheet metal brake take a wall panel and cut you some 24 inch tall horizontal panels and break it at 12 inches to your angle of the carport roof angle. Then screw that to the existing wall matching the panel ridges. A little silicon at the top seam and you're set!

Your roof panels will go under the new cut and bent wall sections.

Does that make sense? Just think of it as ridge cap upside down. You can match your wall color and make it look almost seamless!

That's pretty much my plan - thanks!

As you can see in the pic - I have the 4 4x4 posts in place and the concrete is set now (poured Saturday morning).

This evening I had to deal with another issue - running a drainage pipe under the lean-to so I can fill with dirt and then bring some gravel in. Pipe is in, and mostly covered, now I need to work on the dirt a bit back there.

How do you plan to flash that so it doesn't leak?

Gutter Runner said:

How do you plan to flash that so it doesn't leak?

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This ^^^

Even if you don't care about if water runs down between the two you'll still need to do something so it doesn't rot out those 2x6s.

I'd have probably cut the metal along where the lean to roof is starting then tucked flashing back up underneath and finished the rough edge off with some J-channel.

Actually coming off that end of the building it wouldn't have cost but a few hundred dollars more to just continue the trusses out, then down the road you could turn it into another bay easily.

Why do I here banjos? Take the siding off and do it the correct way. You will regret that for years to come.

Gutter Runner said:

How do you plan to flash that so it doesn't leak?

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I'll work something out. Patience, grasshopper.

barnumb said:

Why do I here banjos? Take the siding off and do it the correct way. You will regret that for years to come.

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It's a lean-to, not an addition to the house. Pretty sure I won't cry about it's shortcomings in future years

While I never intended for mine not to leak, I have been in there (trapped) during a hard rain storm and not seen any leaks (from the roof). I was quite surprised. Now I'm sure it does leak somewhere up there but for the most part its good enough for me.

DRM said:

I'll work something out. Patience, grasshopper.



It's a lean-to, not an addition to the house. Pretty sure I won't cry about it's shortcomings in future years

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The header is gonna get soaked, rot out and fail. A day would get the siding off the header installed and flashed with two people. I'm not jabbing at you, just looking at the future and I see trouble where a days work would eliminate for good. Good luck however you do it.

I gotta do it to mine next year down one side and across the back, 78' total. That might take a three day weekend...

barnumb said:

The header is gonna get soaked, rot out and fail. A day would get the siding off the header installed and flashed with two people. I'm not jabbing at you, just looking at the future and I see trouble where a days work would eliminate for good. Good luck however you do it.

I gotta do it to mine next year down one side and across the back, 78' total. That might take a three day weekend........

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I'll work something out to seal it up... it may not be the "right" way, but I'll figure it out :laughing:

I'm used to building things to handle snow loads so I may be overthinking it here, but I'd at least run a 2x6 along the back of those posts with that 10' span to help support the roof.

No pics, but scored a free load of gravel last night from someone at church. I think the Dakota was a wee bit overloaded

I will get some pics tonight.

Got a little more work done today - All that is really left is to get some metal for the roof and figure out the dreaded sealing where it meets the wall

I will update with pics in the morning.