# Building a shed - 30' x 20'



## Kung (Jan 19, 2004)

First DIY thread! 

Ok, about 9 months ago my wife came into a job that allows her to work at home full time and make a pretty decent buck. Long before that, I'd been searching for a way to create more storage space in our house, or at least near it. I had two options:

1. Enclose the 25' x 28' carport attached to our house. The advantage of that would be that our house would instantly gain 750 or so sq ft, and be considered as an actual part of our house. The disadvantage is that not all of it would be storage, and it would cost quite a bit more than the second option, which is to....

2. Build a shed. So that's the option I went with.

Initially I was thinking small - maybe 12' x 14'. I really only 'needed' a place to put some garden tools and lawn mowers; but as time went by, I realized that given my wife's job and our newfound ability to pay things off more quickly, I would be seriously remiss if I didn't consider enlarging it to at least handle some storage space (on the floor, on shelves and in the overhead).

I settled on a shed 30' x 20'. That'll be more than enough to handle some storage space for household items, for garden tools, AND for some woodworking stuff.

After drawing up plans and sourcing materials I realized very quickly that either myself or friends of mine had more than enough skill to build the entire thing, with the exception of the concrete base; and not even a week after deciding to build it, I literally ran into a guy who spent his entire Army career designing buildings and pouring the concrete bases and such. While I may end up having a small part of it (possibly the roof) done for me, the vast majority will be done by myself and with friends.

And with that, I'll end the posting here tonight, and will start in tomorrow on what's been done so far, with (some) pics.

And that's where I end the posting tonight


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## Kung (Jan 19, 2004)

Ok...I'll state right now that while I'm no idiot, I'm not a concrete specialist; so this will be explained as best I can. I say this because I can just see someone who's poured concrete his entire life step up and tell me how I've gotten these 432 things wrong, or what have you. LOL I may not do the best job, but that's why it's a DIY job. 

So obviously the first step was to figure out where the site was. Ideally I'd think you'd want to place it (probably) where it requires the least amount of leveling. This is entirely dependent upon where you live. In Missouri it's not exactly the Rockies, although it has enough rocks. LOL

It so happened that one of the most level places in my back yard was about 40 feet away from the power pole in our back yard. This made things quite easy - not only would I have a level surface, but I'd have an easy time running electrical to the site.

Once the site was identified, if you plan on pouring a concrete pad (and I did), you'll most likely want to level the pad. The site I picked was pretty close to level, but 'far' enough away that it required a bit of work, maybe 2 hours or so. The local guy charged $270 for 4 hours - being as I had stuff elsewhere on my property that needed scraped, we went ahead and hired someone to level the pad. (Yes, I recognize that I could have rented machinery to do this myself; but the simple fact is that where I live, unless you know someone who owns the machinery, it costs 2x as much to do certain things yourself. Case in point: 4 hours of leveling the site cost me $270 when I had someone do it. Had I tried to rent the same machinery it would have cost me *$875.* That was ridiculous. I decided to save some money and do no work in the process. LOL)

Once the site was leveled, given the fact that I wanted a concrete pad, the real work began. I'd decided quite a while ago that if I had a shed, it would have a permanent (concrete) foundation. That means a gravel base, with rebar, metal fabric, then a vapor barrier on top of that before pouring the concrete.

The guy leveling it somewhat 'screwed' up - he ended up digging down too much at the front right hand corner. Ironically, that's the corner that we based the leveling off of (more on that later). As such, we had to build it up quite a bit, so that it was at least level with the ground there. (We want the concrete pad to be at least a few inches above the ground, so rain/wind/etc. don't inhibit drainage or cause backwash into the shed.)

This meant dumping one hell of a lot of gravel. So far I think we have about 5 dump trucks full of gravel - mostly 'chat' with some larger stuff. We dumped a load or two, roughly leveled it out by eye, then dumped another load or two. 

At that point, my friend brought his leveling equipment (consisting of a tripod with a sensor on a stick). We determined the 'most important' corner - in this case, the front right corner, which was/is the lowest corner - and set the level on the stick equal to that, and then walked to each corner, dipping the stick to the left/right, determining where the same height at each corner lay. We determined that the back had to be built up quite a bit - almost a foot, so that it's not only level with the front, but actually an inch or two above, so that if any condensation/spills occur on the inside, they'll tend to run towards the front of the building and drain out.

That's the point we're at now; the gravel pad is built up such that the gravel is just even with the front. Thus, once the concrete is poured (at a depth of 4 to 5 inches, with a slightly deeper thickened edge), it'll be a few inches above ground level.

Attached are some pictures showing the pad. The first picture shows the 'lowest' point - the corner closest to me. It is slightly above ground level as is. The second shows the same thing, along with metal fabric, rebar, etc. The gravel off to the right is for a small bit of leveling, as well as dressing up the edges of the concrete once it's poured/finished up.



















The third picture shows the back, and how high above ground level we had to get it to ensure that it's an inch or so higher than the front. The dimensions of the shed are about 30' x 20', but as you can see in the picture, the concrete forms stop about a foot or two short. Which is fine - this means that once the shallow ditches are dug around the inside perimeter to form the 'thickened edge' of the concrete, the gravel will extend beyond the back end of the foundation a foot or so, and we can shape it some to neaten up the edge of the back. (Which we'll do all the way around, of course.)










If you stand at the edge in the third picture where I was, and walk forward to the other back edge, and turn right, you're at the corner opposite the first picture. Looking forward, you can see the front edge, with a pipe sticking up, and off in the distance a power pole. The pipe is the stubbed off conduit, inside of which is 10/2 with a ground that we'll tie into my power. (It so happens that my next door neighbor is a lineman for the local power company, so we asked him what was needed, and executed it - a foot deep trench with Schedule 40 conduit sitting on a shallow bed of gravel to give it a base to rest on and NOT flex.) It'll be filled in soon; but we wanted to wait until the foundation was poured to finish it up.










And that's where we're at now. There's a smidge more building up to be done, and then within the next week to week and a half, the concrete will be poured. We'll post more pics then.


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## DaleK (Sep 23, 2004)

Nice start. I would have let the concrete slope a little bit toward your entrance though. Level concrete = wet concrete when it comes to sheds.


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## Dixie Bee Acres (Jul 22, 2013)

> . I'd decided quite a while ago that if I had a shed, it would have a permanent (concrete) foundation. That means a gravel base, with rebar, metal fabric, then a vapor barrier on top of that before pouring the concrete.


If, by metal mesh, you are talking about remesh or rewire, it isn't doing you any good at all if its under the vapor barrier. The point of the wire is to add strength to the cement, help keep it from cracking as much when it expands and contracts.
Put you vapor barrier down, lay your mesh on top of that. Pour the cement, and as you are raking the cement into place to level it, use a rake to lift the wire up into the cement not remaining below it.


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## Muleman (Nov 8, 2013)

Looks like you got a good start going there. I look forward to seeing the progress of the rest of the building. I quit using wire mesh quite a few years ago in favor of the fiber added to the concrete in its place. Many people say you do not get as nice of a finish with the fiber, but I have never found a slick shop floor to be a benefit and in most cases add a small amount of water and it is dangerous. I do use rebar still and have never had any of the slabs I poured crack under weight of vehicles etc. Nothing wrong with using the wire mesh, just for those considering a similar project another choice to consider before hand. Thanks for sharing your build.


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## Kung (Jan 19, 2004)

DaleK said:


> Nice start. I would have let the concrete slope a little bit toward your entrance though. Level concrete = wet concrete when it comes to sheds.



Dale - I mention the back of the gravel base being higher at the back, for that very reason.


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## Kung (Jan 19, 2004)

Dixie Bee Acres said:


> If, by metal mesh, you are talking about remesh or rewire, it isn't doing you any good at all if its under the vapor barrier. The point of the wire is to add strength to the cement, help keep it from cracking as much when it expands and contracts.
> Put you vapor barrier down, lay your mesh on top of that. Pour the cement, and as you are raking the cement into place to level it, use a rake to lift the wire up into the cement not remaining below it.



*facepalm* You're absolutely right. Wasn't thinking when I typed that. lol


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## Kung (Jan 19, 2004)

Muleman said:


> Looks like you got a good start going there. I look forward to seeing the progress of the rest of the building. I quit using wire mesh quite a few years ago in favor of the fiber added to the concrete in its place. Many people say you do not get as nice of a finish with the fiber, but I have never found a slick shop floor to be a benefit and in most cases add a small amount of water and it is dangerous. I do use rebar still and have never had any of the slabs I poured crack under weight of vehicles etc. Nothing wrong with using the wire mesh, just for those considering a similar project another choice to consider before hand. Thanks for sharing your build.



Good point. We're actually not completely polishing the floor - we're leaving it rough for that very reason.


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## fordy (Sep 13, 2003)

.............If , you haven't poured your cement , look into incorporating some......Weld Plates into the slab ! Make them 6"x6" or 8"x8" and put them in all 4 corners and in the mid points of your slab ! On the bottom weld some 3/4" steel rod , then use a torch to bend (2) rods at 90 degree angles(for each weld plate) so that they are facing opposite directions . You'll incorporate them into the wet cement , then you can weld steel upright posts to them after the cement cures . Even , IF you use wood the steel posts will be much stronger than any kind of wood posts you could have chosen . I would use 3"x3"x1/4" square tubing , Yes it will be pricey but when the 'Big' Wind visits your land , that building will still be there . , fordy


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## Muleman (Nov 8, 2013)

Honestly, Fordy did remind me of 1 regret I have had. I wish I had added some weld plates to my shop floor at the time I poured it. It would make it much easier with some of my fabrication projects to have a weld plate out in the floor I could tack pieces to for support during a build. I know, different reason than Fordy had, but would be handy for various reasons.


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## Kung (Jan 19, 2004)

fordy said:


> .............If , you haven't poured your cement , look into incorporating some......Weld Plates into the slab ! Make them 6"x6" or 8"x8" and put them in all 4 corners and in the mid points of your slab ! On the bottom weld some 3/4" steel rod , then use a torch to bend (2) rods at 90 degree angles(for each weld plate) so that they are facing opposite directions . You'll incorporate them into the wet cement , then you can weld steel upright posts to them after the cement cures . Even , IF you use wood the steel posts will be much stronger than any kind of wood posts you could have chosen . I would use 3"x3"x1/4" square tubing , Yes it will be pricey but when the 'Big' Wind visits your land , that building will still be there . , fordy


Good point, fordy. I'll have to bring that to the attention to the guy helping me.


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## fordy (Sep 13, 2003)

Kung said:


> Good point, fordy. I'll have to bring that to the attention to the guy helping me.


 .............One last thought.......if you plan on running your power under ground in a ditch.............you'll want to install a 'Sweeping' 90 degree 3 or 4 inch PVC in a corner of the slab where you want your electricial panel to be located . You'll install it under the forms where it will stick up above the slab 3 or 4 inches . Use duct tape to seal both ends while pouring your slab . This makes it very easy to 'Pull' your large power cable from outside to inside of your slab . , fordy


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## Kung (Jan 19, 2004)

fordy said:


> .............One last thought.......if you plan on running your power under ground in a ditch.............you'll want to install a 'Sweeping' 90 degree 3 or 4 inch PVC in a corner of the slab where you want your electricial panel to be located . You'll install it under the forms where it will stick up above the slab 3 or 4 inches . Use duct tape to seal both ends while pouring your slab . This makes it very easy to 'Pull' your large power cable from outside to inside of your slab . , fordy


That's already done. If you look at any of the pics except for pic 4, you'll see a pipe that sticks up quite a ways. That's the pipe with the 10/2 w/ground in it.


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