Shed project: slab reinforcement

[usenet-659f31de7f953aeb]

I'm building a shed. Part one is complete, preparing the site for a slab; it's leveled, graveled and framed. We're thinking to do the pour later this week.

A friend of mine, who does concrete for a living, is helping with this part. I'm afraid that he might not be a professional, just one of those amateurs who gets paid, because he's telling me that we don't need any reinforcing steel in a shed slab. Except that at 12x20, the slab is big enough for a garage. Although I'm not building a garage (a garage needs a permit, and a shed does not), far down the road it's possible that someone will try to use it as an RV parking pad or something.

Am I right to think that we should lay in some steel before pouring? The expense would be minor, and I can't think of any other downside.

[gfretwell]

The most important part is having a solid base under the slab. If you disturbed the natural soil did you compact it?

If I was building on a slab I would make it 8" to a foot deep on the perimeter 12" wide with 2 rings of continuous rebar and wire mesh across the slab. bend up a short 90 several inches above the slab from a full length rebar that is tied to the ring, for a ground electrode.

[aemeijers]

Flat slab, or stem walls to set the shed on? I hate sheds (even metal ones) on a flat slab- the floor is always wet. At a minimum, I'd set J-bolts in the slab to hook a row of block on, or at least tie down the sill plate with.

And yes, you need at least a monolithic (thick slab edge) footer with rebar, and 4" fabric across the field of the pour. Don't forget to set it up on rocks or chunks of brick or something, so it is in middle 3rd of slab cross section. (They sell fancy little notched blocks of concrete to wire them in place, but about anything that won't rot will work.) If you think you or next owner may actually use this shed for heavy stuff, best to put a proper footer down past frostline. It isn't a patio- it has a building sitting on it.

-- aem sends...

[RobertPatrick]

[e-mail] wrote in news:4a10bf5c.434427632@localhost:

If you live where the ground freezes you need to take special precautions. I don't know what they are, but it only makes sense.

[RicodJour]

You should double check the permit information. Typically it's the size of the structure that determines if it is a shed or not. Building departments aren't usually fooled by someone calling something by another name to wriggle out of securing a permit, and they get kind of touchy when they have to prove it to you.

As far as the steel, if you have poor soil conditions and drainage, and aren't going to do proper subgrade preparation, the rebar will help a bit if the rebar is of sufficient size and the slab is of sufficient thickness. If you take care preparing the subgrade the rebar doesn't really do much and won't prevent cracking.

Google newsgroups for: bob + morrison + slab if you want to read up on it. Bob passed away a while back and his depth of knowledge is sorely missed. If your contractor friend disagrees with anything Bob wrote, well, your friend is wrong. Simple as that.

That's the third silliest thing I've read today.

R

[benick]

He doesn't know what he's talking about..I'd put in wire mesh and rebar...If in a cold climate , I'd add 2 inch styofoam under it as well...JMHO....

[Ed Pawlowski]

I'd use wire mesh, same as I did in my patio about 7 years ago.

[John Grabowski]

*I concur. I would add steel, a moisture barrier and insulation. If you are planning to bring power to the shed I would stub up a pvc conduit to the interior wall. As someone else suggested stub up a piece of rebar for bonding or run a solid #6 copper into the slab and connect it to the rebar.

[ransley]

You are lucky on one count , my county requires a permit for "sheds" bigger than maybe 8`x8` How about your tax increase for that mini shed you are building that is not a garage, I bet it will happen. For that size reinforcing the concrete is a good idea.

[gfretwell]

Make that a #4, tied to the rebar

[John Grabowski]

*You're right. I was thinking to a ground rod, but to a concrete encased electrode it must be #4 copper.

[Anonymous]

I watched a neighbor use chain-link fence as "reinforcement" when he poured his patio.

Looked pretty good.... Any reason why it'd be better/worse than rebar ?