Slab pour inside frost walls

[Sawlog]

Hey, new here.
I'm just got done digging the footings (by hand) one my to be 26x44 garage.
I dug them 12in wide and 32in deep. I'm going to put 2in foam board on the inside wall and pour this trench full up to ground level. I will add rebar of course.
Then I plan to ether forum up and pour or lay concrete block up to floor level. That will get me 6in above the road.
My question is, have any of you poured the garage floor inside the frost walls and not over the wall where the garage door openings are? My thinking on this is that way the whole floor could move if needed. Typically I see on jobsite that everybody leaves the wall cut out for the man doors and overhead doors. Then when pouring the floor it goes out even with the outside of the concrete wall. Seems to me that would street the floor in those areas.
Also, if you poured the whole floor inside the walls then the whole slab would be insulated by the perimeter 2in foam board that would be cut at a 45 on top.
Thanks

 

[Kevin54]

WOW!!!! Have you ever really done anything like this before? I hate to say but what you are wanting to do sounds like a ramass way of doing things without any real thought at all.

I understand that you have to be down to the frost line for your footers, but what you are doing is not right in my mind. And you are going to be using up a lot more of concrete than need be. Do you even know if your trench is perfectly square? So why not dig it out a little wider to have room to work, pour a proper footer, then lay block up to the desired level, then pour your floor inside? And yes, you need to lay out where the doors are going to go so the block or wall is at the proper width.

Unless I'm really missing something, you need to think this out some more.

 

[ford33]

OP if you are in the Chicago area, you will need city or village inspections for concrete work. Check with your local authority and get their garage handout. Most have handouts now and this will help you.

Second recommendation is to have the concrete work done by a pro. You specify what you need and let the pro do the work.

Good luck

 

[Sawlog]

WOW!!!! Have you ever really done anything like this before? I hate to say but what you are wanting to do sounds like a ramass way of doing things without any real thought at all.

I understand that you have to be down to the frost line for your footers, but what you are doing is not right in my mind. And you are going to be using up a lot more of concrete than need be. Do you even know if your trench is perfectly square? So why not dig it out a little wider to have room to work, pour a proper footer, then lay block up to the desired level, then pour your floor inside? And yes, you need to lay out where the doors are going to go so the block or wall is at the proper width.

Unless I'm really missing something, you need to think this out some more.

if I poured a 8x16 footing then poured a wall just to the ground level that's 12.25 yards of concrete. If I do it my way it's 10.4 yards of concrete and saving probably 750 bucks in wood to build forms. My trench of concrete will be 10in wide, blocks or wall will be 6in or 8in wide. I have plenty of room to square up perfectly before I go on up after the ditch is full. But to answer your question, my ditch is on the money now. A 2 czr garage on our property was built this same way in 1950, it is still looking great. I was asking if any of you ever poured the floor without going over the wall in the door ways.

 

[Sawlog]

OP if you are in the Chicago area, you will need city or village inspections for concrete work. Check with your local authority and get their garage handout. Most have handouts now and this will help you.

Second recommendation is to have the concrete work done by a pro. You specify what you need and let the pro do the work.

Good luck

Way south in a small village, no codes or permits needed here.

 

[Chris705]

Yes on pouring up to a man door. Cut insulation ata 45 as you describe. I did not pour my OH doors that way. I insulated inside of foundation wall up to top of OH door opening ran short width of insulation board on top of wall & formed edge of floor slab right at middle of where the door comes down. Intent is to pour apron and driveway on other portion of foundation wall when the time is right.

 

[ConCretin]

Nothing unusual about earth formed walls in many parts of the country and btw, good call on the insulation. You could do a curb wall and then place the slab within or you could place the slab first and add the curb on top. You are correct that pouring a slab first or even through door openings will restrain the slab from shrinking and could cause cracks but it is pretty typical and control joints will help ensure that any resultant shrinkage cracks aren't visible.

 

[Fatboy148]

Nothing unusual about earth formed walls in many parts of the country and btw, good call on the insulation. You could do a curb wall and then place the slab within or you could place the slab first and add the curb on top. You are correct that pouring a slab first or even through door openings will restrain the slab from shrinking and could cause cracks but it is pretty typical and control joints will help ensure that any resultant shrinkage cracks aren't visible.

I am impressed with the ambition to dig as much as you did OP. The highlighted section would have been a whole lot less digging for you.

 

[spudley]

Make sure your base is firm. A successful slab is only possible with proper prep on the base.

 

[wssix99]

This is OK to do and we can get away with Illinois dirt this time of the year. As long as the rains stay away and the trenches stay good, all is good. If rain comes and they erode, then things go bad and the concrete price can go way up.

My question is, have any of you poured the garage floor inside the frost walls and not over the wall where the garage door openings are?

Yes, this is how I did my home, but many people pour over the walls where the openings are to save money/time.

I had many pours, so I was able to form my slab perfectly rectangular, inside the walls. I then (on a separate day) poured a separate thin threshold, pinned to the foundation wall beneath. My walls are 12" thick, so I also have the benefit of a nice, wide 12" threshold. I also formed my dust lip into this piece. The threshold stops at the outside edge of my wall and I have an expansion joint there, where my driveway starts.

^ This keeps all the movement isolated and also helps me keep everything thermally isolated, as well since I have a heated slab. (I don't want "tongues" of the heated slab sticking out under my garage door into the elements.)