looking for ideas. just thinking out loud for now.
i probably know what i have to do, i am just hoping for a budget solution.

my original plan was to sell my house at a good profit. buy another and build a large garage to fit my needs.
prices have gone beyond stupid so i will probably keep my current home / garage and update.

the IDIOT who built the place made a nice LOOKING but useless garage, 24' X 35 with 9' walls.'. the idiot only pored MAYBE a 4" thick slab. couldn't tell you how he got that by the inspector. built in the early 70's.
he also sloped the driveway directly towards the garage and the entire floor is lower than the driveway. the floor is flat without any ramp like part leading into the garage that a proper built garage has. needless to say every time it rains water pours into my garage pretty much making it storage only building. the thin slab combined with water problems cracked the floor in several places. the only good thing is there are a couple of floor drains in the garage helping get rid of the water that pours into the garage.

my question is it possible for someone to grind the slab and then pour a 6" thick slab on top of the existing messed up floor?


also he built the garage in the lowest spot on the lot. after he poured the slab he only put 1 course of block on the slab and then built the walls on top of that. the problem is the dirt around the garage is about 1' higher than the block in a few areas. when i bought the house i re graded the lot trying to keep water away from the garage. i built a french drain to help any water that puddles by the water to drain away from the garage. this has helped but it needs to be improved.

my question is it economically feasible to lift up the garage, add a couple of course of block and then set the garage down on the higher walls?
if i did this combined with a thicker slab i would have a pretty nice usable garage.

is this idea feasible? or would it just be cheaper to knock everything down, rip up the slab and start over?

who would i contact about discussing doing something like this?


thanks in advance for your ideas.

It all comes down to money. It shouldn't be a problem for a house moving company to raise your existing garage enough to put in two more courses of block. Once that was done, if your current floor has no voids beneath is, I see no reason why you couldn't pour a new floor over the old. In fact, if you wanted to change elevation, a sand fill on top of the existing floor could do that. Again, it all comes down to money.

If you did use a sand fill, then floor heat would be an option.

You need to spend some time with a good contractor in your area talking about various options. You know what you want to do so now you just need to have a contractor look it over and tell you what will be cost effective and what won't. If you're in the city then you need to check with the building department to see what kind of codes apply. The city may or may not let you do what you want.

A good grated drain LENGTHWISE in front of your garage will take car of the water and should be affordable. On the floor, several different options. If your desire is to get a lift in there, have you thought about possibly trying to raise the ceiling just above where the passenger compartment would be or the entire lift area ?

I'm going to guess that lifting the existing garage would cost as much as building a new one. They'd need to poke holes in the existing row of blocks to get I-beams in. They may even have to break and trench the floor depending on the height of the beams they use. They'd have to excavate at the perimeter to get the jacks under the beams. Everything would have to remain in place while the next row(s) of blocks were installed. Then you have to clean up all the mess that's left after they're done. Yikes.

If you tore it down carefully you could probably reuse a lot of the materials. Depending how much you want to raise the floor it could be a ton of money to do it in solid concrete. I don't think I'd use sand between the two layers - I'd probably opt for compressed crushed stone.

I made the mistake of building my shop at ground level. Luckily I've had no water issues yet. I have virtually no slope - only 14" over 120' feet to the street.

I'm considering some french drains.

A 4 inch slab is a standard thickness for non commercial grade structures.

Pouring fresh concrete over existing concrete is not unusual. The company I work with does it frequently on remodel jobs when slabs are out of level.. You have to rough up the existing slab a bit and coat it with a commercial concrete adhesive, then apply the new concrete. We have used "Ardex" with pea gravel mixed in but our thicknesses have been less than 2 inches. This is quite expensive though. Ardex is a self leveling concrete powder and is not as structurally strong as actual concrete that has rocks and sand mixed in with it.

Sell the house for a profit and by another house with property big enough to put up a 5000sf shop with 4" slab with rebar and build it. stratospan has some pretty good deals on steel buildings, my shop is stick built with 4" slab and rebar, its 3500 psi concrete, works great for me, i did however figure out where i was installing my lift and dug some footings in that area about 2'x4'x18" deep, kinda overkill, but i figured what the hell whats a little bit more mud in the grand scheme of things. build it bigger than you need because some day you will want it bigger.

this.**** And this*** "A good grated drain LENGTHWISE in front of your garage will take car of the water and should be affordable " " you can pour concrete at 2" with bonding agents and add plasticizers . it needs to be rough as stated and you can also get a higher psi [4000] strength concrete. i don't know the cost in your area but about 5-6 yards will be all that you need. [i would guess $1200.00 plus additives and add finishing labor ] if its settling and cracked, you can use a jack hammer or a skid steer with a hammer to break and settle the current slab to prevent future cracking!

Thing I see as a problem is potential water under the slab and frost heaving. You're going to have to figure out how to get the water away.

All this talk about drains ... you could dig a moat around the shop BUT where does the water go ??? You have to get the water AWAY from the shop, not just keep it out of the shop.

You are correct sir.
I was referring to the OP's decription

Quote

he also sloped the driveway directly towards the garage and the entire floor is lower than the driveway.

A neighbor built a new house 10 or so year back and did the exact thing described above except for the floor being lower part. He ran a 6" wide cast iron/steel grate the entire width with a large 8"? pipe under it and has had zero issues.
If the surrounding are is below the floor (his was). The OP's sounds like it may not be? If not, one might be able to use a sump pump or similar devise. Just trying to come up with cost effective solutions for the OP.

Years ago when I bought my property. the previous dipsh-t put up a 30x48 metal building 300ft downhill (fairly steep grade) from the house. Well he tried a shallow drainage ditch to direct the water away. That wasn't working to well by the time I bought the house 5 years later. OK, so I noted inside, at the bottom of the walls there was pressure treated wood about the height of the outside dirt? A little work with a shovel revealed MR. DS had covered the pressure treated wood with what appeared to be roofing tar paper that was disintegrating. [censored] was this guy thinking?
So we had the area regraded to just below the wall creating a drainage ditch alongside and out back of the building a ways. Added matching metal siding slipped under the existing side. Back filled with a little dirt to just cover the bottom of the siding and so far, no more water

THANKS for the replies and ideas

If you pour a slab directly on top of the old one it will crack in the same spots as the cracks below, it is the nature of concrete. You could put rigid insulation down, then poly and then the new slab.
With the price of materials, it is not going to be cheap either direction you go.

40 ton hydraulic jacks inside the block-wall on 4 corners. Use 6x6 attached to walls and ceiling to jack up on, work it even (1/2” at a time) till you get the extra height then block it and install a new plate. Those walls are strong enough to support themselves and roof, if you feel you need one more post in the middle of the 38’ do it. Jack a little at a time, I’d do two more 8” block to get over 10” clear. We did my sisters house this way. Drill holes in slab to find hollow spots (usually just tapping on floor will tell you that and rolling a floor jack across floor you can hear the difference) fill the voids then pour the 6” slab (reinforced concrete) on top of old floor.
Forgot, use 2x4s at 45 degree angle to support wall (on each corner) on the outside like when doing a new wall, move ground tie in as it goes up.