Concrete footer and floor pour...

[Overhaulin63]

Okay I first want to ask that you excuse my ignorance because I am in uncharted territory when it comes to building a garage or pouring concrete.

So, what if we dug the footer as wide and deep as needed and poured the footer and the floor at the sametime and then blocked it up a couple of courses from there. I haven't figured out the diffference in laying block (block and labor) vs. pouring the footer and the floor at one time.

Any thoughts or suggestions?

Thanks

 

[cj7jeep81]

Okay I first want to ask that you excuse my ignorance because I am in uncharted territory when it comes to building a garage or pouring concrete.

So, what if we dug the footer as wide and deep as needed and poured the footer and the floor at the sametime and then blocked it up a couple of courses from there. I haven't figured out the diffference in laying block (block and labor) vs. pouring the footer and the floor at one time.

Any thoughts or suggestions?

Thanks

Not sure with where you live, but here, it would most likely have to be separate. They building inspector would want to inspect the footers to make sure they meet code before covering them up with the floor.

 

[12ozd]

So, what if we dug the footer as wide and deep as needed and poured the footer and the floor at the sametime and then blocked it up a couple of courses from there.

It's called a monolithic slab.

Not sure with where you live, but here, it would most likely have to be separate. They building inspector would want to inspect the footers to make sure they meet code before covering them up with the floor.

Can't have monolithic slabs in Indiana?

 

[cj7jeep81]

It's called a monolithic slab.


Can't have monolithic slabs in Indiana?

I was thinking of the more traditional footer and slab (like they did for my basement), so yeah, I could be wrong.

 

[Jackfre]

We poured the footer and short walls to extend 6" above finish floor elevation. Installed 1/2" homasote expansion strips Inside that and poured the floor. Cut 1" expansion joints the next morning. 4 weeks later, no cracks...so far. This was a good manageable method. There is a lot going on when doing concrete and I kinda like it in stages.

 

[joes169]

Location, and is this an attached or detached garage?

 

[Overhaulin63]

Good info!

I live in Ohio and yes it is a detached garage.

 

[icenfire01]

I did a mono slab for my attached garage. The nice part was it was all done in one pour. The only thing I dislike is the fact that my walls sit directly on top of the floor so I get some water intrusion with really hard driving winds. Not a big deal but something to consider. I did use greentreat for the wall footer for this reason.

 

[diver165]

Lurking here... going to build a 16x20 garage and have been given 2 ways to pour the floor.

 

[tlmartin84]

It's done everyday.......

 

[diver165]

It's done everyday.......

What is done everyday?

 

[12ozd]

Put waterstop around/in the slab when you pour.
Pour wall on top, will be completely watertight !

 

[tlmartin84]

What is done everyday?

Pouring monolithic slabs.......

 

[joes169]

Good info!

I live in Ohio and yes it is a detached garage.

What you're most likely looking to build for a slab is a monolithic, as mentioned above. This style of slab is also referred to as a floating slab, turned-down slab, or grade beam slab in other area. Generally speaking, the slab has a thickened edge (around here, it's usually 12" thick or more, and 10" wide or more) that tapers up at a sharp angle to the middle of the garage, generally 4-5" thick. At least 2 rows of rebar are placed around the outside perimeter, near the bottom, for re-enforcement. The idea behind this type of slab/foundation is that it gives adequate strength to the slab where it needs it, at the perimeter where all the static wall weight bears. These slabs are susceptable to frost heave though, but it's generally not an issue, and un-noticable in most situations.

From your original description, it sounds like you're attempting to design a foundation that has frost protection. I wouldn't attempt to do that with a monolithic pour. I realize there are areas where it's done, but IMPO, it is far from best practice, and has a myriad of potential issues...........

 

[Jlbc212]

What you're most likely looking to build for a slab is a monolithic, as mentioned above. This style of slab is also referred to as a floating slab, turned-down slab, or grade beam slab in other area. Generally speaking, the slab has a thickened edge (around here, it's usually 12" thick or more, and 10" wide or more) that tapers up at a sharp angle to the middle of the garage, generally 4-5" thick. At least 2 rows of rebar are placed around the outside perimeter, near the bottom, for re-enforcement. The idea behind this type of slab/foundation is that it gives adequate strength to the slab where it needs it, at the perimeter where all the static wall weight bears. These slabs are susceptable to frost heave though, but it's generally not an issue, and un-noticable in most situations.

From your original description, it sounds like you're attempting to design a foundation that has frost protection. I wouldn't attempt to do that with a monolithic pour. I realize there are areas where it's done, but IMPO, it is far from best practice, and has a myriad of potential issues...........

^^^ I agree. Any wood framing, including pressure treated stuff, should be a minimum of 8" (preferably 24") above the finished grade. This not only gets the frame away from any water and ground moisture, but also the siding. Most of the United States is also plagued by termites and carpenter ants. Damp wood is a magnet for these invaders (rodents too). With the siding and frame near the ground, it becomes difficult at best to see their invasion before extensive damage has occurred. Sadly, foam board insulation placed up against concrete also gives these invaders protection from detection. Where I live in New England I won't build anything without an adequately deep concrete frost wall extended above the surrounding grade. There's lots of old barns here, built in the 1700's and 1800's. They are post and beam structures, very similar to pole buildings. The only ones that have withstood the test of time are those with a good foundation and a maintained roof.

 

[thewatusi]

We poured the footer and short walls to extend 6" above finish floor elevation. Installed 1/2" homasote expansion strips Inside that and poured the floor. Cut 1" expansion joints the next morning. 4 weeks later, no cracks...so far. This was a good manageable method. There is a lot going on when doing concrete and I kinda like it in stages.

Wow. Hope you like mold.

 

[tlmartin84]

Wow. Hope you like mold.

LOL, again monolithic slabs are poured everyday with finished elevations just a few inches above final grade.

As long as drainage is good. There are no issues. You use treated seal plates on the bottom of the walls, and hold the plywood up 1/2" or so. Shouldn't have any issues with mold or moisture.

 

[diver165]

I know that one for sure. My Dad's 18x30 shop is almost 30yrs old. We built it on a mono pad that was only 3in above grade on one of the 30 ft sides. It NEVER got moldy, leaked or anything like that. AND it was never exposed to direct sunlight because of the shops orientation to the house. We did lay slotted pipe down that side and back filled with gravel. The shop had 2ft eaves and no gutters. Nothing ever got on the siding except a few splashes of dirt after a really hard rain. It was sheeted with a hardy board siding that looks a lot like the LP Smart Side panels (but it was before that products time).

Now if we were to do it over again we would have added a ring of block around the building and gutters for added piece of mind. But this was before the days of the internet where you could google block laying and figure out how to do to do it on your own lol.

 

[thewatusi]

LOL, again monolithic slabs are poured everyday with finished elevations just a few inches above final grade.

As long as drainage is good. There are no issues. You use treated seal plates on the bottom of the walls, and hold the plywood up 1/2" or so. Shouldn't have any issues with mold or moisture.

He was talking about using homasote (glorified cardboard) as an expansion strip between a floating floor and poured walls.

 

[Jlbc212]

This http://www.garagejournal.com/forum/showthread.php?t=250138 is an example why wood shouldn't be placed near the ground. Just because lots of builders do it, it doesn't make it a good reason for you to do it too.
You can build something that may last your lifetime, but a well-built structure will be still standing and without need for major overhaul by your great-grand children.

 

[tlmartin84]

This http://www.garagejournal.com/forum/showthread.php?t=250138 is an example why wood shouldn't be placed near the ground. Just because lots of builders do it, it doesn't make it a good reason for you to do it too.
You can build something that may last your lifetime, but a well-built structure will be still standing and without need for major overhaul by your great-grand children.

That is not a fair/good comparison........

The concrete floor was poured above the seal plate....

The seal plate was not treated......