can you join cement

together if you pour footers for walls and later pour a floor? What would you do to make it work?
Making a tractor shed.

Not sure about your situation, but I've seen guys drill the wall and insert short pieces of rebar to connect wall to flooe. It's still going to shrink/crack where the two come together. If it was me, I'd put in expansionmaterial and keep them completely separate, so if one moves, the other one doesn't have to.

This may not work for your application though.

Good luck

Tim

use a wood key way inlaid in the top of fter ,, walls in some applications will use 1/2fiberbd against wall , there is no secure bondin agent thati konw of ..

Unless you live where it does not freeze, the footers should be below the frost line!
If they are on top, freezing will be from outside in on the building floor, and my best input would be to have a floating slab floor. Use open cell urethane foam strips along the footing (sill seal 6 inches wide and maybe 1/2 to 3/4 inch thick.) This prevents movement of either from affecting the other. I use a combination of both Fibercrete, and 4"mesh at 6" for work floors. Jim

Here's what I've done. Pour your footer. In my case I go down at least 3 feet and make a solid footer under my overhead doors. I then later on pour the floor right up to it. No need for any expansion material and you sure don't want it tied in as something is always going to shift. Concrete seems to contract as it dries anyhow leaving a small gap.
This is in my pole buildings. Pour right up to and around the posts too.

I built a block wall for the foundation down to the concrete footer and then when I poured the floor inside I used that fiber-sheathing material that comes in 4x8 sheets as an isolation joint. No problems so far.
Zach

I dont' know about barns, but for houses, the footers and concrete floors are ONE pour...
8)

You can join or should I say, "tie in" concrete using epoxies, deformed metal bars (rebar) on or in existing concrete, but its not "monolithic" (one) in a manner of speaking, as their is a joint, both are not formed and placed at the same time.

You propose to form and place a spread footing for a wall, typically the footing has a key way and vertical rebar to accept the wall, to tie it in to the footing. Not so typical is what you are considering, tying a slab edge to a footing.

Most footing, wall and slab details, (looking in section) will show the wall as described above, with the slab edge on top of footings, independent of the footing and wall, (not tied in). Columns, or posts in this case may have footings, set under the slab, both are also typical to have an isolation joint, using expansion joint material, like asphalt impregnated fiber strips, board, or whatever is the latest material for that purpose. All the structural steel buildings I've worked on had column isolation joints, I believe to eliminate cracks projecting from sharp corners. I don't ever recall seeing a slab edge tied to a footing on any building I've worked on or blue prints with wall/footing/slab details. That is not to say its wrong, but definitely a non typical detail. I would think the slab being independent of the wall would prevent any wall settlement from influencing or imposing forces on the slab edge.

Highway slabs are adjoined to one another, if you have ever seen new concrete highway pavement installed, where they leave off always has the leading edge with epoxy coated rebar protruding, to tie into the next slab when placed. Typically done like this in these areas, NY NJ metro areas as I recall.

Why not let the floor "float", or do as it pleases? I have a couple floors poured inside walls without issue. My concern is where I want to continue to pour more floor- is to tie the floor joints together, so I don't end up with a ridge there.

Do you have to have concrete walls?? If you are building a shed, why not just pour a slab (for machinery prob. 6" thick) and build off of that?

You can do it that way no problem, just leave rebar pins sticking up or pour a keyway in footing so the wall will be attached to the footings. Make sure your footings are at least 16" wide so your floor will set on footing also. mike

O.K. I have now got a good idea of what can and cannot be done. and I will work it out. Thanks a lot.