Opinions on expanding this building.

[dougf]

Hi everyone!

Long time lurker here, I really appreciate the knowledge and advice given on this forum. I did some searching and didn't really see what I'm looking to do with this cheaper prefab tube style building, so I thought I would post and get some advice from the knowledge base here. I have almost no idea what I'm doing, fyi, and will try and give some background first!

I did the classic mistake of buying something too small. I had a specific budget in mind, instead of waiting for more funds I ended up getting a 20x30 with 10' walls prefab square tube style from Alan's Factory Outlet. I made some mistakes for sure, such as following the directions on their website about making the slab 1' wider and longer for some reason (probably so the installers don't blow out the concrete as easy when anchoring) but overall happy with it. My slab is a monolithic slab with about 10" on the outer edges and 6" thickness inside, with a vapor barrier and rebar. To include to gravel I paid $7,500 for that, then $9,600 for the building.

I collect antique machinery and gas engines, weld inside, and collect anything antique and cast iron. I found out quite quick that the 20' depth is killing me. So, I have an idea to kick out the back side 10' in sort of an enclosed lean-to method. I am in Missouri in Waynesville, and think I can get away with a 1/12 pitch which would drop the end wall height to just above 9' which would be fine to line machines with (I think).

Ideas on the best method? I think its going to be relatively simple. I think my method of attack will be to get a 10x30 slab poured onto the backside, remove the back panels, remove the back wall vertical supports, span the 30' with something beefy along with the end vertical supports (perhaps a center beam also?), attach the lean-to as high as I can using either stick or metal tube frame, and enclose it with hopefully the same color Slate Blue panels.

With all the vast experience here, does anyone see any pitfalls that I haven't thought of, such as the new slab moving, inadequate supports with the added lean-to, inadequate pitch for the metal roof, this just looking goofy and not being usable, etc... This is really one of the only flat-ish spots on my land, and I really did think of just selling it and starting over now that I have more funds available. Thank you all for your time!

 

[Maxcustody]

Watching this. Sounds like a good plan. Much better off to add on than start over. Prices for everything is kinda crazy but it is what it is. Looks like a good foundation to start with. How about some inside pics.

 

[K'ledgeBldr]

Anything is possible! It’s just a matter of how much money are you willing to throw at it- and would it get you what you want.

 

[Old Man Roger]

My first thought was to extend it length wise, to keep the pitch of the roof and the height of the ceiling the same.

 

[ycgoat]

I agree with adding to the side, assuming you have land there. Depending on my budget and space I might try to make it taller in the middle for a lift or loft (Monitor Barn)

 

[Old Man Roger]

Maybe just add another shed from the same manufacturer to the side?

 

[WNYflyer]

First question would be does the construction needed to be permitted by your municipality?
Assuming retaining the existing building the easiest solution would probably be to add on to the side with a new structure from the manufacturer of the original building. Would probably need to make the new building self supporting so that it doesn't throw any additional load into the existing building. Changing roof heights may also be a problem if drifting roof snow needs to be addressed in your area. Also the common wall between new and existing might have to be retained in some way because it maybe a shear wall? Who knows, thus the reason to perhaps deal with the manufacturer of the existing building since they should have the info on the existing building.

 

[dougf]

Thank you all for the replies. I'll post some inside photos when I get off work. No permits needed outside city limits here for something hobby size like this, and maybe a separate building 90 degrees to form an L, with a concrete pad area to work would be smart too. I could also place a garage door on the back side of the existing that opens up to the pad and would in essence increase my area to work on projects in decent weather. .. Thanks for the ideas!

 

[readhead]

I am doing a 12x30 leanto addition on a building right now. The original building company was no help for the owner. He called me and I am waiting on a permit so we can get it done.
As WNYflyer mentioned above the addition will be self supported and not connected to the existing building. Two of the bays next to the existing building will have X braces and it works out that I can transfer the roof diaphragm into the opposite wall for shear. Your plan is sound. Is there a permit involved?

 

[dougf]

Thank you for the reply, no permit involved. I am also worried about what you WNYflyer said, which is transferring additional load to a cheap square tube frame building. I would appreciate knowing how you will tie a self supporting structure into an existing structure whenever you have the time.

 

[larry_g]

My first thought on your original idea is only remove 10-15' of the back wall for a pass through That gives you some wall on each side to back machines/storage up too. It also reduces the size of the beam to support the opening.

That said, I agree with the above ideas of extending the end wall out. You can extend the end wall some distance 10-15' and make it 25 or 30' deep. Then choose to align the front wall, align the peaks, or align the back wall. The roof height on the addition can be higher than the original building. That is what did on my first shop, had a raised roof on one section to give room for a second floor in part of the building.

lg
no neat sig line

 

[readhead]

The frame is not attached but the roof and wall sheeting can be continued as needed.

 

[CraigStu]

My main concern is as WNYflyer says about that rear wall. I think it is pretty certain that it is a shear wall. Would a standard 36inch man door through that wall to your addition work for you? Thinking that a man door could retain the shear strength. You might be able to go w/ 2 man doors. Also I'd make the new back wall shorter. Bring it down to maybe 6ft so you have good slope on the roof. Arrange things in the shop so you have machines, shelfs, etc against that wall.

 

[firebirdparts]

Thank you for the reply, no permit involved. I am also worried about what you WNYflyer said, which is transferring additional load to a cheap square tube frame building. I would appreciate knowing how you will tie a self supporting structure into an existing structure whenever you have the time.

I would have just assumed that you can't. If you remove the back wall, then you have no choice but to support both buildings off the new "thing". With a lean-to, no argument is possible. The new metal thing is holding up both buildings, and they're light, but whatever load exists is transferred back to a point on each end of the new beam. You may not have footers for that, but again, the buildings are light.

 

[dougf]

Thank you all. Each decision I analyze and draw out has its own set of issues i'm seeing.

1.) Attempt to **** another building up against the end that's deeper, the company wont install if there isn't 3' of space around each new addition so I would have to do it myself, which I'm not capable of. If I put another one next to it 3' away it will look odd.

2.) Just send it and do a lean to attached to the cheap tube frame and attempt to properly transfer the load to the earth, gravel it and park my mowing stuff under it.

3.) Kick out a lean to like above and attempt to enclose it and hope I can track down the correct color metal siding.

4.) Slap myself in the face and start over because I knew better than to settle for something I knew was ultimately too small but I had the "do it now or it will never happen" mentality.

5.) Gravel and slap a carport behind it completely separate to park the stuff under.

6.) Have a larger building built over the top of this, disassemble the small one and sell it, then pour a slab inside (lol)

I know I'm over thinking this.

 

[readhead]

Both buildings can have their own headers for the opening. Depending on the concrete that is already there you may have to cut and install a couple of new footings to support the new header.

 

[readhead]

I think you may be dealing with the wrong people for this. Most carport companies can’t think beyond very simple designs. Contact Versatube and they should be able to design what you need.
I am a Versatube dealer and they have designed several difficult solutions. It doesn’t hurt that I have been a structural steel fabricator for twenty two years also.
PM me and I might be able to give you some suggestions.

 

[dougf]

readhead (and everyone else), thank you so much for the suggestions and taking the time to reply and provide suggestions. I'll keep you in mind and send you a message if this is the way I go, still undecided and currently looking to just throw another building up right behind it for the yard/storage/mowing/garden stuff and be grateful for the dedicated 20x30 "play house" as my wife calls it.

 

[CraigStu]

Another building is going to be the easiest answer. You just need to decide on it's size. I think I'd let the company build it like they say w/ that 3ft gap between buildings and then I'd come in after they are gone and put an extra wide man door in both and a short breezeway to connect them.

 

[finn]

Keep your existing low investment building for the lawn and garden equipment storage and bite the bullet and build a proper shop with quality construction elsewhere on your property.

Keeping yard tools, kids bikes, etc separate from the shop makes life easier.

Adding on to what is, in effect, a temporary building makes little sense.

 

[dougf]

Well... with over a YEAR of contemplating this I have finally started. 14x30, 6" slab with 8" thickened edge to match existing, pinned to existing mono slab with epoxied rebar. Excited as heck to have more room to fart, drink beer, pick my nose, and lose stuff.

I'm also a little nervous, after researching beam sizes required to spam my 30' while supporting the additions rafters I may have to rethink my open span plan. I wanted to 1/12 down to my 8' end wall from the 10' existing, but it wont be so bad to have a smaller opening into my machine room I suppose... with whichever way I go i'll update this thread.

 

[dougf]

I have ordered most of the materials from Menards, I should be getting a call shortly for delivery of my 2x10 rafters and 16' black pbr panels. I ordered everything 16' to give myself some room to work with but the addition will be 14'.

Still completely on the fence about making this a lean-to or enclosing it in. It would be a great place to keep my bigger hit and miss engines, tractors, and I could maybe fit my 1950 chevy truck out there which would give me a good sized area for projects inside the 20x30. I'm thinking this is PROBABLY the better and smarter option, since can finish the 20x30 and heat it easier (and maybe cool it if I get a mini split).

 

[CraigStu]

A smaller opening between the two will be no problem. In a previous house I did an add-on workbay on the side of a 2 car garage. Contractor cut out 2 studs in the wall which gave about a 4ft wide opening. that worked out just fine. Our current house has a bearing wall right down the middle of the basement. I didn't like that idea and asked the builder for options. Steel I-beam was best but also most $. He asked what if we put three 6ft openings in the wall? It is not a finished basement so no need for a big room and the 6ft openings have worked out just fine. One portion of the wall has an additional fridge and a freezer against it. Another portion I went crazy w/ screw in hooks and some large nails and now all our luggage, back packs etc hangs there. Another same thing but all the beach chairs, umbrellas, coolers, etc hang there. For you, I'd go w/ a stick built wall w/ one 6ft opening and one 4ft opening and your longest span will be that 6ft.

 

[dougf]

A smaller opening between the two will be no problem. In a previous house I did an add-on workbay on the side of a 2 car garage. Contractor cut out 2 studs in the wall which gave about a 4ft wide opening. that worked out just fine. Our current house has a bearing wall right down the middle of the basement. I didn't like that idea and asked the builder for options. Steel I-beam was best but also most $. He asked what if we put three 6ft openings in the wall? It is not a finished basement so no need for a big room and the 6ft openings have worked out just fine. One portion of the wall has an additional fridge and a freezer against it. Another portion I went crazy w/ screw in hooks and some large nails and now all our luggage, back packs etc hangs there. Another same thing but all the beach chairs, umbrellas, coolers, etc hang there. For you, I'd go w/ a stick built wall w/ one 6ft opening and one 4ft opening and your longest span will be that 6ft.

Thanks for the advice, I think that would work fine for what i'm doing. I appreciate the ideas.

 

[dougf]

Just wanted to provide an update in case anyone is interested in doing the same thing to their metal building. Framed the 14x30 extension with 2x4s 16" OC. Bolted a 2x12 to the metal studs using 1/2 bolts then built up the three ply beam with nails and glue, it's supported at the ends and every 10 feet in the center with a 6x6 secured to the concrete so there's no span issues. I've been hanging to 2x10 rafters after work (pretty time consuming by myself) and hope to get the purlins (though I might sheet it so its easier to walk on later) and metal up by Sunday evening.

Everything's going fine, but I do worry about removing the metal studs and the bottom plate at the bottom. The way these metal buildings are made they sort of have a scissor "truss" and im concerned they may spread under load and push the framed wall out, so that's something i'll have to fully consider before cutting out the 30' portion of studs and sill.

 

[readhead]

The existing "truss" will not spread since you are bearing on the new header. You have the same situation on the other side where the doors are and there is a lot less header on that side. Since you have a pretty shallow pitch break I would suggest that you extend the new flashing at least 18"-24" up under the existing roof and a foot onto the new roof. You don't want water from snow melt to migrate under the existing roof. Cutting out the bottom rails is no issue at all. Everything looks good so far.

 

[dougf]

The existing "truss" will not spread since you are bearing on the new header. You have the same situation on the other side where the doors are and there is a lot less header on that side. Since you have a pretty shallow pitch break I would suggest that you extend the new flashing at least 18"-24" up under the existing roof and a foot onto the new roof. You don't want water from snow melt to migrate under the existing roof. Cutting out the bottom rails is no issue at all. Everything looks good so far.

Thank you for the advice, I appreciate the time you (and everyone else) have taken to provide input!

 

[dougf]

Made quite a bit more progress over the last couple weeks. Everything’s went relatively well and I’m hoping when everything’s buttoned up it will look better. Looks a tad awkward, but oh well I guess! Flashing was a B But after the last rain I just had one small drip every 5 minutes in one spot, so I’ll jump up there tomorrow and recall and check things. It was at the end where I was in the F it stage with the knees and back so I’m sure it’s a simple fix.

Started cutting the inside supports and I’m contacting Carolina carports this upcoming week to try and get some King Blue metal for the back 8’ wall. If they won’t work with me it’ll be Ocean Blue panels from Menards. It’s a close match but not exact.

 

[dougf]

Figure I owe an update. The extension worked out fantastic, I now have "enough" room at 30x34 I can get some projects done like finishing some of my hit and miss engines and other items. If I could do it over I would have just done the 30x40, but finances, getting out the military and finding a job constrained what I could initially spend. Overall I'm grateful and still have to finish insulating.

I made a ton of mistakes that I highlighted earlier in this thread, so if your interesting in a metal square tube building (Carolina Carports) I would suggest reading through it.

 

[no704]

What’s the slope on that roof? What material? U get snow?

 

[dougf]

What’s the slope on that roof? What material? U get snow?

The expansion is right at 1/12 pitch, we do get snow, haven't had an issue yet. Just had 7" sitting on it without leak or issue. The expansion is No. 1. southern yellow pine 2x12's, 16" on center.