Detach 48x28 Garage - Footings

[ponytug]

It's always been a mystery to me how a pour crew can elevate mesh to the middle of the wet slab while they are walking around on it?

Yes, well the answer is that they don't generally do a good job as there is no way to control the rebar height accurately. Lots of testing has shown that it just doesn't reproducibly get the rebar into optimal position. I cringe every time I see someone do it.

Using dobies, or chairs, or stone/bricks are much to be preferred.

All the best,

Peter

 

[ovrszd]

Yes, well the answer is that they don't generally do a good job as there is no way to control the rebar height accurately. Lots of testing has shown that it just doesn't reproducibly get the rebar into optimal position. I cringe every time I see someone do it.

Using dobies, or chairs, or stone/bricks are much to be preferred.

All the best,

Peter

I think I agree. Although you are quoting "rebar" rather than wire mesh. Rebar is usually set on plastic chairs. You can step on them and they will rebound and put the rebar back in the middle of the slab. "Wire mesh" is simply laid on the pad.

I've saw local DIYs use bricks as chairs. I really like that idea.

I've never heard them called "dobies". Why I love Internet forums.

 

[m1garand762]

We dug the footings as a complete rectangle so there will be a footing under the doors. We will run horiztonal rebar (three #4 bars in a 24" wide footing). We won't run any vertical bars under the door area but will of course have verticals at 32" and 16" oc depending on the wall area that was called out for.

I'm doing a 5" slab on grade pour after the ICF stem wall is done. Entire garage walls will be ICF (6" concrete core with 3" foam on each side).

All the footings and slabs will be 4,500 psi hydramix mix (water resistant). $168 per yard for that mix.

What brand of ICF block are you using

 

[etpm]

Yes, well the answer is that they don't generally do a good job as there is no way to control the rebar height accurately. Lots of testing has shown that it just doesn't reproducibly get the rebar into optimal position. I cringe every time I see someone do it.

Using dobies, or chairs, or stone/bricks are much to be preferred.

All the best,

Peter

When I had the slab poured for my shop I had rebar and wire in the slab. I had grade beams too. Like you said I was dubious about the ability of the workers to pull the wire and rebar to the proper position. I ended up positioning it myself using stone. When the guys came to do the work they were surprised I did all that "extra work" that they said was me just wasting my time. As I watched them sloppily work I was so glad I did the extra work. They did not make the slab flat nor did they slope it. Instead they put a big dip in the slab. 1 inch dip over 15 feet. Since I was building a machine shop the floor was thicker than normal, 7 inches minimum. It's a good thing I went so thick after discovering the large dip.
Eric

 

[Pettrix]

What brand of ICF block are you using

Nudura with a 6" concrete core

 

[Pettrix]

I've always been told 24".

2 post or 4 post lift?

Both, a 2 post and 4 post

 

[Pettrix]

Guys sorry for the dumb question, why do you use block instead of just forming and pouring the concrete to the desired height?

Thanks,

ed

You mean the ICF stemwall?

 

[ponytug]

I think I agree. Although you are quoting "rebar" rather than wire mesh. Rebar is usually set on plastic chairs. You can step on them and they will rebound and put the rebar back in the middle of the slab. "Wire mesh" is simply laid on the pad.

I've saw local DIYs use bricks as chairs. I really like that idea.

I've never heard them called "dobies". Why I love Internet forums.

I figure to do concrete pours once. If it cracks on me, or has some other defect, I know myself and it would annoy me every time I walked past it.

I use chairs or dobies when using mesh as well. The sweet spot for steel reinforcement is about a third of the way up the slab, regardless of whether it is rebar or mesh. I would say if the bricks are the right height for your pour, run with it!

All the best,

Peter

 

[m1garand762]

Nudura with a 6" concrete core

Ok thanks, that’s what we are use for the house

 

[ovrszd]

Both, a 2 post and 4 post

For the 4 post, no big deal. They stress the concrete very little.

For the 2 post you need to thicken the concrete at the post locations. Easiest way is to simply create a bowl at the post locations to thicken the concrete. 10-12". Sometimes sonotube is used.

When drilling the concrete for the wedge bolts, drill all the way thru if you can.