Garage Renovation question

[BrentD]

I've got a little 2-car detached garage that was apparently built around the same time my house was back in the 1930's. It's got a dirt/gravel floor and has tongue and groove siding on the outside. One side of the garage has sunk about 5 inches since I bought my house and since the garage is dark and dirty it doesn't get much use. It's probably safer to put my cars under the metal carport.

What I've been thinking about, however, is somehow pouring a concrete floor under the garage. Maybe start by lifting the walls one at a time and supporting them then pouring a curb under them with steel left sticking out far enough to join with the steel for the rest of the garage floor.

Normally I'd just tear the building down, but I've got a bit of a problem with local codes.... When my garage was built it's overhang was right on the property line so the outer garage wall is about 12 inches from the property line. City codes require any new construction to be at least 5 feet from the property line and there's not enough room between the house and the garage to move it over and still allow a walkway into the back yard. I spoke with the city inspector and he says I can do anything I want to with the existing garage without a permit, as long as it is not expanded or moved from it's current location.

So my question to you guys is, is this practical? Has anybody ever done this? If I go to the trouble of pouring the floor, would it be worth my time to dig a pit on on one side so I can more easily work on my vehicles? Any tips, pointers, etc?

 

[pat32rf]

We had the same situation with a 100yr old garage at our last house. Pole barn type frame, loft above, lean-to shed (big enough for small car) on the side. Two walls one foot from property line. I was young and tied up with work at the time so I hired a contractor to A-straighten the whole thing, B-pour a concrete curb/foundation, around the walls and C-pour a concrete floor in the main structure and the side shed.
When I got home the first night the building was straight (well almost). When I got home the next night they had poured a floor using the outer walls as a form. The frame poles were left in the concrete floor. I wasn't happy but the concrete was set.
That was about 30 years ago and the structure is still there. When we sold ten years ago all we had done in addition to the floor was new roofing......(and wiring, and some heating,etc)

 

[pat32rf]

If you get into a pit situation then you are opening a real can of worms. To be safe you will need explosion proof lighting, exhaust fans etc (gas fumes are heavier than air). If you have the head room you might be able to design some fold out ramps that you drive up. Even a 4" depression in the middle so you have "creeper" room. Your ramps could be hinged into this depression giving a level floor.
One thing that I always seem to need is an overhead hook that will hold an engine, ATV, skidoo, etc. Again its a question of headroom. Could you put a beam accross?

 

[ultrarunner]

I've had the same situation with several 1920's detached garages. No way the city would ever permit new construction. In fact, my neighbor was over zealous and he with 2 buddies tore his garage down one weekend... after a year of trying, with much expense and paying an architect, he gave up and had to build his new garage in a new location and lost valuable yard space.

What I did was buy enough 3/4 threaded rod washers and nuts to raise the garage 6" above grade and poured a new slab. No freeze problems in CA so I didn't go with any special footings. It's been over 25 years and nothing has moved or cracked.

I pressure washed the inside and painted the wood a month later after it had plenty of time to dry out. That along with two windows made it a very usable and functional space.

I also ran a cable for 3 #10 wire for power and a phone line.

You're on the right track...

No pit option for me... not allowed anymore and city requires commercial application for variance.

 

[2manyrocks]

I had to replace the concrete grade beam on one wall of our barn built in the 30's. Turned out to be easier than I worried about. I was worried about coming up with enough jacks to lift the building and then I saw how to do it with posts and wedges which was no real problem.

I attached a ledger 2 x 6 with bolts into the top of the wall and then used 4x4 posts set at an angle to jack the wall up. I only raised the wall enough to clear the old grade beam foundation. The 4x4 posts rested on a 2x10, and an oak wedge was driven in with a sledge hammer between the 4x4 posts and the 2x10 to raise the wall off the bad foundation. The old concrete grade beam was pretty easy to break out. Then I cleaned up the footer with a shovel, set forms and poured a new footer. Then laid block. My wood sills were also shot, and I had to replace them, too.

During the time I was doing the prep work, I also put concrete blocks under the walls to further stablize them.

You may not do yours the exact same way, but the point is that it can be done without necessarily having to buy a bunch of steel and jacks.

 

[RonMar]

Archemedes said it best: "Give me a big enough lever, and I can move the world".

The trick is being able to support the wall and leave enough clearance to dig, form and pour a footing. If the structure is still sound, I say go for it. I just got done(almost) insulating, paneling and adding new shop lighting to my detached garage. The difference in usefullness and comfort in the space, particularly when it is cold and wet outside is incredible. A small Kerosene heater makes it comfortable to work in less than an hour. It is so nice now, I may even get some projects done this winter...

 

[2manyrocks]

Ultrarunner's method is also a good one. Plus, if done right, the threaded rod supports the building until the pour.

 

[radioman]

my sister has a exact same type of garage you were talking about. she lives in a historic zone and she cant modify the outside, she cant tear down and rebuild deu to new zoning codes. her garage sits right on the edge of property line. Half of the floor is gone, just dirt and the other half was rotten wood floor over dirt. I went in and ripped out the wooden floor, had contracter come in with bobcat to dig new footers and pour new foundation walls. I covered the dirt floor with plastic and installed wooden I joists 16 OC and installed new plywood flooring on top. If you want to use as car storage, If the foundation is ok- then just have a new floor poured. IF not then now is the time to bite the bullet and have the walls, foundation fixed.

 

[2manyrocks]

This picture may help visualize one way of lifting the wall. I added a red line in the picture where bracing could be added to further stabilize the wall once it is up. I probably should have added this brace about every four feet or so, but didn't think of it until now.

Keep in mind that I removed a concrete grade beam that was about three block high. I didn't lift this wall 18" into the air. I did remove a sag where the wall had sunk because the foundation had given way, and I straightened a bow out of the wall.

If your garage is located in an area where vandals might come along and knock your braces out, then I'd be thinking about supporting the wall with temporary cribbing, concrete block, all thread or something else until I was ready for the pour.

If you try to lift all four walls at once, you will have to add more bracing to be absolutely sure the building isn't going anywhere until you set it down on the concrete.

 

[BrentD]

2manyrocks: That is exactly what I was thinking about. The building itself doesn't currently have ANY concrete at all. The two side walls have their posts sunk at least 4 feet deep into the ground. I've never dug down any further to see exactly how deep they go.

There is one slight problem that may complicate matters however. A few years ago I was having some inside remodeling done at a time when I was not in a position to do the work myself. While I was at work, my dad was sort of overseeing the work. He took it upon himself to ask the guy doing the work to see if he could level out my garage, then left. When I came home from work I discovered that the guys idea of leveling out the garage was to pry the top plate of one of the side walls loose, hammer cut pieces of 2x4 to the side of the existing studs to extend them up and then set the roof back down on them. He even totally disregarded the wiring I had done and stretched it to the point that every circuit shorted out and tripped my main 200 amp circuit breaker. When I asked him about it, he said it was fine when he left. I find that rather strange since he should have realized there was a problem the minute the lights and all the power tools stopped working.

As it stands now, I'm not sure if that wall is still even nailed to the studs anymore. Sometimes I think it's being held up by the sheer force of the will of the rats that have taken up residence while it's been unused due to no power, no lights, no floor, etc, etc.

Anyway, thanks so much for the ideas. At least I know it can be done, and has been done. Will probably nix the pit idea but may instead see if I can't come up with some sort of folding ramp system as was suggested.