# Garage Conversion- Footing/stemwall issue



## GAK_WA (Jan 28, 2014)

I am starting a garage conversion where I will be enclosing the garage by pouring a new footing and stemwall where the garage door used to be. this is so there is a continuous foundation. The approved plans show to match existing footing and stemwall. the footing is 6" x 12" and the stemwall is 6" x 24". I will be installing rebar per the plans and drilling and epoxying them into the existing footings. 
My question is how should I go about and do the pour? it is only 16.5' long and the concrete required is 0.4 yards for the footer and 0.6 yards for the wall.
Should I do a monopour or seperate pours?

I do not want to dig to far into the existing garage because that is just more concrete I am going to have to replace. I would like to use the existing dirt as one side of the forms and just set up a one sided form but I was told that may not be allowed. Then I though about lining the existing dirt with Rigid foam insulation and using the insulation as one side of the concrete form. Has anyone every heard of this.

I see a problem with getting any wood forms out of the inside of the footing/stemwall and don't want to leave it in there to rot.

Attached is the idea I had with the rigid insulation.

Any suggestions would be helpful. thanks


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## Gary Evans (Jan 27, 2014)

I would mono pour it and bite the bullet.......pour the concrete to the dirt, don't put styrofoam in there.......it's got no strength anyways.

Use 1x4 cleats sitting on the 2x6 to support the wall, form the wall, the inside and outside corners, brace & plumb and pour.

Good call by the way....... drilling and epoxying the rebar into the old foundation.


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## joecaption (Nov 30, 2011)

Why would you even need a stem wall added?
Is this a local code?
I personally have never seen anyone do a garage conversion and add a stem wall.


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## GAK_WA (Jan 28, 2014)

The garage floor intersected the driveway in the middle of the foundation so any new in-fill wall would have been half on the smooth surface of the driveway and half on the rough, exposed aggragrate or the driveway. Also code was that when converting garages, you must have a continuous footing/foundation. Since my house did not (the footing and stemwall stopped on either side of the garage door) I had to connect them. Technically I could have poured just a footing (10x12, 8x12,...) where the garage door was but thought it would be better to match the existing so it doesn't look like a conversion.

GE, how would I use cleats to support the wall if I am pouring to the dirt? There would be no 2x6 on the inside. would I leave a PT 2x6 in the ground for the footing, install cleats on top, then build the wall on both sides? I may be able to get the inside wall form off and out but any forms used for the footing would be left in place.


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## Gary Evans (Jan 27, 2014)

It's always better to strip the forms after the pour as much as you can but if one 2x6 for the footing was left on the inside that would be ok, part of those 1x4's that pass through the new wall will have to be left anyways.
Without seeing exactly what your doing it's very difficult to give you advice that's more specific.


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## jomama45 (Nov 13, 2008)

GAK_WA said:


> The garage floor intersected the driveway in the middle of the foundation so any new in-fill wall would have been half on the smooth surface of the driveway and half on the rough, exposed aggragrate or the driveway. Also code was that when converting garages, you must have a continuous footing/foundation. *Since my house did not (the footing and stemwall stopped on either side of the garage door)* I had to connect them. Technically I could have poured just a footing (10x12, 8x12,...) where the garage door was but thought it would be better to match the existing so it doesn't look like a conversion.
> 
> GE, how would I use cleats to support the wall if I am pouring to the dirt? There would be no 2x6 on the inside. would I leave a PT 2x6 in the ground for the footing, install cleats on top, then build the wall on both sides? I may be able to get the inside wall form off and out but any forms used for the footing would be left in place.


In 25+ years in this trade, I can't say I've ever witnessed that in my career. Are you sure the top course wasn't just left off so the floor could run continuous over the top of the foundation? 

It's actually more work to build it originally as your describing, thus why I'm questioning if it really is the case.............


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## Gary in WA (Mar 11, 2009)

The fb would not be feasible, IMO. Have a welder? Use 6" spreader cleats for the legs on the inaccessible side of footing, with the monopour bracket welded to it. Attach other end on the 2x6 form, elevated to the 8" same as weld, remove from 2x later; no wood left in for termites to access your room later at slab/wall joint if fb insulated, Zone 4; http://energycode.pnl.gov/EnergyCodeReqs/index.jsp?state=Texas
First and second pics;
http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_8_par034.htm

Move cursor over map; http://www.termites101.org/termite-basics/termites-by-region

Gary


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## Gary in WA (Mar 11, 2009)

Another option; dig the inside close to wall forms, undercut for footing. Add bottom spreader cleats to inside form with a 6d nail, driven just enough to pull form away later. Lower that into position, add 2x footing form with a flat 2x4 face nailed on top so it forms a 2" footing width, lower outside panel into spreader clips, nail through bottom wall form into edge of flat 2x topper with spreader clip sandwiched. Drop a 2x4/1x4 alongside the inside panel bottom to fill against concrete push up, fasten by adding 2x/1x vertical blocking- flat- on sides of panel= will hold horizontal filler from raising with mud pressure. May require wire at intervals to hold up until mud pushes on lower rail 2x fastened to verticals. No wood left in concrete. Footing at inside is dirt formed. Add flat 4' braces on slab, nailed through inside top form into 2x for support of inside wall form.

Gary


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## Gary Evans (Jan 27, 2014)

Holy cow.........that's getting pretty fancy.
I think that will work.

Or you could build it the easy way and just dig the damn thing out with a shovel and a big crowbar.
It's extra digging........just make sure when you backfill after it's poured you use water and compaction.


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## GAK_WA (Jan 28, 2014)

I attached some photos. I was thinking something like what Gary was mentioning. It would be a one-sided pour. The forms on the outside could be braced against the side of the trench away from the garage and using something liek a 2x8 for the footing form with a 2x4 (or ripped 2x6) flat on the top of the 2x8. I need 3inches of footing sticking out from the wall. the secure the bottom of the wall form to this and use enough bracing along the bottom, middle, and top to the form withstands the lateral pressure. My concern was if a one-sided pour was allowed. Someone mentioned to me it might not be. I sent an email to the building dept to ask. Thanks for all the advice!


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## Gary Evans (Jan 27, 2014)

A picture is worth a thousand words.

3/4" plywood on the outside with pegs on the inside holding it in place ( steel or wood ) spreaders at the top till you place the concrete then take them out and brace the outside of the plywood.
Use a 2x6 "L" nailed at the bottom and outside of the plywood for your footing........give you an extra 4.75" wide x 5.5" high footing ( 2x4 will make it just under 3" wide)

Easy......but remember, concrete is very heavy so pay attention to those outside braces.

And 1.5" - 2.5" Styrofoam SM on the inside if you want a below grade thermal break........and save a bit of concrete.
Keep that up about 5 or 6 inches from the bottom so it allows for a bit of a footing on the inside.
It would also be handy if some of this new foundation supported the underside edge of the floor......by at least 1.5 inches.


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## Gary in WA (Mar 11, 2009)

Since the slab is probably sloped to the big door, how are you doing the floor system?

Gary


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