Concrete foundation for shed

[Alan L.]

15x20 or 16x20 doesn't matter to me. I need to measure the bricks and work from there. I will be dry stacking them so I need to figure what would fit with the least cutting. I want the two rows of bricks to keep the wood off the ground. So if I go 16x20 the shed will only be 16x16 and the extra concrete will be a porch with roof over top. I want to use that area to hoist up Elk for skinning and it will keep them out of the sun/weather as well. I have a reason for everything and it will all work out in the end.

BTW just to prove my point I work on computers for a living and I built a pergola for my house and never had any of the plans on paper. My wife went nuts wanting to know if it was going to work or not. I had never did anything like that before and I think it turned out well. Look for your self.

I don't understand the need for bricks if you are using a slab. I'd pour the slab where its higher than grade (I'd use 2 x 12s so it would be 11.5 inches tall). Put down a treated lumber bottom plate and it won't be making contact with the ground at all. I'd also dig a trench around the perimeter and maybe a couple across the width, put rebar in the trenches and tie to rebar on horizontal part.

 

[crazyal]

Around here a shed of that size I would just go with a floating slab. Like others said, put down some sand that can be leveled and compacted easily. Buy some straight 2x6 from your lumber store and pick up some stakes (lowes sells them) and simply make and level the form. Just make sure that the form can't shift as it will have some weight pushing on it when the cement is wet. If you don't want to buy stakes another way is to use a 2x4 screwed to the outside of the form and drill a hole in it and use rebar. I would just plan on buying plenty of rebar, a 4' x 4' grid would be overkill but it's not going to add much money starting about 6" in from the edges.

You can rent a float and a straight bar (at least around here) so most of your work will be done from the sides of the form so you'll not have to worry too much about stepping on the rebar so rocks would work but the chairs are handy. Also put plastic down under the slab and after you pour you'll want to cover the cement with plastic to keep it from drying out.

I would try to have at least 3 people to help me. You'll need two on the straight bar and at least two moving the cement around as it's poured from the truck. Start at one end and start filling in. As soon as you can start with the straight bar the better, cement sets faster than you think. Just slide it back and forth by about a foot keeping it tight to the top of the wood form. Make sure no cement gets between the bar and the wood. If the cement is too thin then stop, throw a little on the spot tha needs it then go over it again. You're looking to make the cement level more than smooth. You'll want to have someone with a rake either pulling/ pushing cement to the bar when thin and pulling it away when it gets too thick. Working the bar is hard if the cement is too thick.

After you get it level you just stand on the side and use the float to smooth out the cement. You can take a shop brush and rough it up if you would like. I would stay away from a power float, for a shed it's not needed but if you want to learn then it's a great place because you're not going to care if you get a few mistakes.

It's really not too hard and if you have someone who's done it before it helps. I learned by helping a coworker do a garage slab and then to repay me for my help he came and helped me do mine. I went a lot further and actually made 2' x 8" poured walls with home made forms. I never did it before and it was real easy. I have a thread about my garage I can find if you would like to see it.

 

[UpToNoGood]

The wood walls and roof will be anchored to the concrete in the blocks as if it was attached to the concrete pad it self. Rebar will be placed in the pad when wet for the blocks to go over and the blocks get filled with concrete locking the blocks to the pad gripping to the rebar. J bolts are also added the concrete in the blocks to mount the wood to.

As for critters getting in I doubt that due to the concrete filled blocks and the exterior will be finished off to look adobe.

I do have a 100 ft tape measure I just need to remember to bring it. I will also use the 3-4-5 rule to keep it Sq.

 

[mjncad]

By the way this is going in New Mexico. It is considered high desert at 7400ft.

Now that sounds quite nice. Dry climate, hopefully relatively cool in summer and not too bitter cold in winter.

BTW just to prove my point I work on computers for a living and I built a pergola for my house and never had any of the plans on paper. My wife went nuts wanting to know if it was going to work or not. I had never did anything like that before and I think it turned out well. Look for your self.

It looks nice to me and you'll like having a backyard on your 40-acres where you have more than spitting/pissing distance between your patio and the property line.

"fubar" - I haven't heard that term for a long time. It's bringing a chuckle or two. Thanks for making my day. :thumbsup:

Fubar is Private Snafu's commanding officer.

 

[UpToNoGood]

It looks nice to me and you'll like having a backyard on your 40-acres where you have more than spitting/pissing distance between your patio and the property line.

Funny thing about my small back yard. When my younger brother first came to see my house I was in the back yard with my Dad. My younger brother opens the back door and says "When one of you guys come back in making room for me out there let me know so I can get a tour"

 

[mjncad]

I've seen even smaller backyards here, and I almost bought a place with such a yard many years ago that makes your current one look spacious.

 

[stub]

2nd the suggestion on getting help. Due a combination of factors, including my impatience, I once poured a 18x18 slab for a room addition by myself. It was cold, so I had them add calcium. I gave the driver a few bucks and he helped me strike it. Then with about 2 feet to go, we ran out of concrete. By the time he came back with another 1/2 yard, the 1st part was hard and the interface part was impossible to get smooth. Set up before I could even float it. I ended up plastering it with thinset to get the finished floor somewhat smooth. Came out ok but more work than needed. I'm an expert now.

Lessons learned: Never pour by yourself, always get help from somebody experienced (reading on the internet is not experience), always order a little more than you think you need and have a place ready to put it, don't add a setting agent if you want to get it smooth.

 

[Egon]

Just build up the pad with good crushed gravel. Set up the outside forms, dig in a perimeter grade beam, line it with poly and have a mono pour. Three fellows should be all that is required if you have centre guides for screeding.

After the finishing damp it and cover with plastic.

Drill holes in the concrete and use screws or expanding bolts to hold the grade beam in place.

Probably don't even need rebar or wire.

 

[KennyG]

Drill holes in the concrete and use screws or expanding bolts to hold the grade beam in place.

Probably don't even need rebar or wire.

Just my personal experience and opinions, but I would never drill and insert if there is any way possible to embed bolts or rebar in the pour. It's much easier and much stronger.

Also, you can always get lucky but I wouldn't go without reinforcement on anything larger/heavier than a sidewalk. Unless you don't mind cracking, of course.