New here-building a 16x20 "mini barn" this summer

IHDiesel73L · May 13, 2010

Hey all-I came across this site looking for information on pole barn construction techniques and I've learned a lot! My attached one car garage is stuffed to the gills and I really need to put up a detached building to hold all of the outdoor power equipment, but I'd also like to incorporate some covered firewood storage via overhangs off of the exterior of the building as well as a stand-up loft for seasonal storage. I don't live on a large lot (1/3 acre) so a "real" pole barn is out of the question. I've arrived at a footprint of 16' x 20' which should do just fine for all of the equipment storage on the main floor along with a workbench and plenty of shelving. I also found a great gambrel truss design for the loft that will give me almost as much headroom as a true second floor.

I'm planning on 4x4x12 posts on 4' centers. I know that some folks frown upon using 4x4s (hopefully my building inspector won't), but I think they should be fine on 4' centers (rather than 6' or 8' as is done with 6x6s/8x8s)-I'd be interested in hearing from anyone who has built a pole barn with 4x4s. The floor will be rock screenings. Maybe one day I'll do concrete, but right now I'm trying to keep costs low, plus once you wet screenings they set up like concrete anyway. The "barn door" will be a 7' x 8' slider on a track, but I'll probably put a man door and some windows in as well. Once the entire building is finished I plan on putting a 6' "lean to" type roof that will run the length of the font(it will look like a "front porch")supported by timbers. This will provide a dry area to stack firewood as well as a covered area just outside the main door to work on things, grill, sit and drink a beer, etc...:licking: I should be able to get 3 full cords under there-if I do a smaller (4') overhang on the back the runs the length of the building I'll have 8 cords total dry storage which is much better than stacking on pallets and covering with plastic which is what I do now. Now for some specific questions:

Poles - Concrete? Gravel? Both? To start off this is New Jersey-I have heavy clay soil that is fairly wet so I was thinking that I would be better off boring the hole (12" diameter-48" for frost depth), pouring 12" of concrete in the bottom, (once its cured) resting the pole on top, backfilling 2' with pea gravel, and then backfilling with 1' of compacted soil. Does that sound right given my conditions?

Trusses - God bless our agricultural extension services! After a lot of searching I found this page courtesy of North Dakota State University's Extension Service:

CONSTRUCTION PLANS

You can find the link to the gambrel truss I'll be using here. They will provide plenty of headroom. The plans called for 24" OC spacing with 2x12x16 joists, but I want to make sure the loft is very sturdy so I'm going with 16" OC spacing.

Girt Boards - As I said before my poles will be 4' on center. The walls will be 8' high-how many girt boards do I need?

I'll probably have lots more questions along the way, but at least these will get me started. I'll also scan some sketches of what it might look like eventually and post them up.

bp fick · May 13, 2010

You got a permit from your township, right?

Seriously, before getting too deep into this, be sure of your local codes and so forth. Get that stuff out of the way first, or you might end up having to do a bunch of re-designing. I am quite interested in this topic and will watch your progress. Best regards.

SPIKER · May 13, 2010

For a MINI barn you might be better off building like other styles, not a pole barn but a mini barn that can be moved, built on skid/floor system. I have one that is almost the same it is 12 by 16 and a 2nd that is 16x20 which was same and I put concrete floor under it later.

Mark

IHDiesel73L · May 13, 2010

bp fick said:
You got a permit from your township, right?

Seriously, before getting too deep into this, be sure of your local codes and so forth. Get that stuff out of the way first, or you might end up having to do a bunch of re-designing. I am quite interested in this topic and will watch your progress. Best regards.

I have yet to have a formal sit down with the building inspector and zoning official, but as far as the basic requirements I think I'm ok. Our town land use ordinance is online and what I want to do is within the maximum height, maximum lot coverage, and maximum square footage for accessory buildings. That being said, it also clearly states that any accessory building over 100 square feet requires a permit. I'm going to go in armed with a complete set of plans-framing details, elevations, etc... If I have to change something so be it, but I want to make it clear to the code officials that I know what I'm doing (or at least look like I do :laughing

-that worked well for me when I got my inspection for my wood furnace. I made sure that I overbuilt everything (heat shields, wall thimble, clearances, etc...) and documented it with detailed drawings, spec sheets for the furnace, vent pipe, and other parts. The inspector basically came over just to give me the sticker and said "After all that I'm not worried about you trying to fudge anything" :thumbsup: Anyway, it will be a slow process but I'll try to post regularly.

Barely Smokin' · May 13, 2010

4x4's on 7 ' centers, diagonally braced in the corners. 2x8 at top of span between the 4x4s. 2x4 near the ground and halfway up each 4x4. 2x6x16 rafters. 2x4 @ 24" spacing for roof.

Holes were @ 36" deep. 4 inches gravel in bottom, fill dirt, compacted. 80lbs bag of quikrete at the top of each hole.

Had about 2.5 feet of snow on that low pitch roof this winter. No problems. Used joist hangers on the top side of the rafters. This particular shed addition required one 2x16x24 for the hip rafter, which got some pretty serious gusseted on each end.

Shelving was very economical use of material. It's just 4x8 sheets ripped in 2' sections that comprise the shelves and vertical end pieces. I erected it all myself. Extremely strong shelving design and connected directly to the 4x4s.

Gravel floor. So far, works great! Let me know if you have questions.

IHDiesel73L · May 13, 2010

SPIKER said:
For a MINI barn you might be better off building like other styles, not a pole barn but a mini barn that can be moved, built on skid/floor system. I have one that is almost the same it is 12 by 16 and a 2nd that is 16x20 which was same and I put concrete floor under it later.

I see your point, but the pole barn works for me for two reasons. First, my town taxes anything over 100 square feet-permanent structure or not, so I might as well have something that is permanent. Next, I have a small piece of property so there aren't many places to move it to :laughing: In fact I'm going to strategically locate it so that it blocks my view of the neighbors behind us-their house is pretty ugly

wedge40 · May 14, 2010

I think it would be worth your while to check on having the Gambrel trusses built by a truss company or building company.

Wedge

peterssj4034 · May 14, 2010

I am building a 20x20 shed, starting tomorrow (the site gets excavated in the morning). I will have a gable roof, but I also will have a loft. I had the trusses made, total cost was just over $1,000. I will build the rest myself, but I am glad I had the trusses made for me.

As for the posts, I am using 6x6 for the corner posts and the front of the shed where I will have the main door. All of the other posts will be 4x6. I'll have a gravel floor as well, to start. For the girts, at the bottom, I am using 3 pieces of 2x8 tongue and groove, treated, then I'll run 2x4's every two feet. My side walls will have 9ft of head room, the loft will have approximately 7 feet in the center.

Hope this helps.

Seth