Suspended concrete slab integrity ?'s

[sailah]

I am under agreement on a house and did the house inspection last Friday. I was glued to the inspector's hip and it was very helpful. The property has a garage/apt that is a renovated barn. There is a 2 car garage bay with a suspended concrete slab that was done in the 70's we think. There are some fairly substantial cracks (to me anyways) that have me really nervous. The inspector shares my concerns, the seller (through his broker) does not.

He had a professional concrete engineer do a report in 2013 that stated he should paint/seal the concrete to prevent further damage, which he ignored. I read the report and it was basically stating to seal it up, job done for $1-2k but that the slab was intact. The engineer does huge municipal parking garages in Boston so he knows his stuff. I spoke to him about my concerns over the phone and he asked me to take pictures which are below.

The crawl space is standing head room, dirt and very damp. It needs to be addressed somehow as there is also some powder post beetles but that's another story. There is access through a low door.

I'd love to hear some opinions about how you would go about fixing this. The seller has said he's not giving any concessions, I already beat him up enough

I should note my intended usage for this garage is to have a woodworking/machine shop in here. I have really heavy tools. I've listed some of the bigger stuff but I also have 1000's lbs of tooling etc.

Table saw 2500lbs
Jointer 1800 lbs
Lathe 2000 lbs
Bridgeport 3000? lbs
Planer 1000 lbs
Hydraulic lift table 800 lbs

First some interior shots















This really shows the whole picture. This is basically the damage on both sides although the right bay (pictured) is worse. Concrete has fallen in and the rebar is compromised in a number of places.






This is underneath looking towards the opening of the garage. There is an I beam between the bays. If you were standing outside garage looking in, this the "right" bay





Crack runs left to right about 8' in from garage door





Looking towards door in left bay



I beam in middle of two bays









I beam is very rusty





Thoughts? and thanks.

 

[coldh2o]

Run away!

Seriously, that slab is severely compromised - cracking, delaminated concrete above and below, major corrosion on rebar... That would be a huge repair project, particularly with the tight quarters. We're talking tens of thousands of dollars, if you can even find someone to do it. More likely scenario would be to remove the floor, fill the crawl space with granular material and pour a new slab.

I'd like to hear what the engineer has to say when you send him the photos - I can't believe he thought that slab was in passable condition two years ago.

 

[readhead]

This is the steel guy. Look for another house. The slab was not placed correctly when it was done the first time. The rebar should not have been that close to the surface.

It can be fixed. A grid of beams and columns to support the slab and some sort of topping on the floor. I would guess somewhere in the neighborhood of 75K by the time it is all done.

 

[jhelrey]

You got your feet in the first pic!

I'd be more worried about the pieced together copper pipping with fins, etc. Makes me wonder what the owner did to the rest of the place.

 

[Michigan Mike]

I have worked in commercial construction for most of my working life. Poured a lot of concrete. I'm not an engineer. If it was mine I would tear it out and redo it. The exposed and rusted rebar the concrete that is busted and looks like it has shifted just makes me very uncomfortable. I woulden't park a car on it much less the heavy shop equipment you are talking about.

 

[gregtwojeeps]

Agreed. Keep on with your new home /garage search or be willing to pay for a new floor = $$$$$$$$$$$$$$$ jmo

 

[Leoruiz]

Complete P.O.S. Move on.

 

[sailah]

Engineer just sent me this email:


It looks like thru their use the deterioration has progressed. I am concerned about falling concrete and tripping hazards and not imminent collapse or structural failure, although this is a natural progression if it continues to be used as a garage and deterioration allowed to continue. The deterioration at the entrance was there, but has progressed.

The extent of concrete repair and coating of rebar has increased . so the cost of repair has increased.

The steel beam corrosion is natural for this type of system in a garage.
The “fix” would be as follows:

1. Have an inspection just to make sure
2. Chip loose concrete to remove spalled items top and bottom, confirm rebar integrity. Apply sika Armatec coting to rebar and act as bonding agent. Patch concrete with Sikatop 123 or like bag mix. Apply sealer healer to slab to fill cracks, may require caulking or taping cracks below, reasonable effort.
3. Apply epoxy garage floor paint to surface with grit and maintain paint. Epoxy coat steel beams below

The garage does not “scare” me, but does need to have the items addressed to preclude further deterioration. No structured garage is maintenance free, by structured I mean garage floor over occupied space. Particularly one built like this for residential use, and built when the industry did not realize the full impact of road salts.

I can think of many other options, all the way up to slab replacement, but that gets expensive. I think the above is pragmatic and would make me feel comfortable.

-Engineer

 

[ADSR]

I wouldn't even think about this one.

Move on.

 

[sailah]

Run away!

Seriously, that slab is severely compromised - cracking, delaminated concrete above and below, major corrosion on rebar... That would be a huge repair project, particularly with the tight quarters. We're talking tens of thousands of dollars, if you can even find someone to do it. More likely scenario would be to remove the floor, fill the crawl space with granular material and pour a new slab.

I'd like to hear what the engineer has to say when you send him the photos - I can't believe he thought that slab was in passable condition two years ago.

The crawl space has standing headroom, I'd have to duck under the I beams, but I can't imagine filling it.

Here's the back of the garage/apt for context you can see white man door for access. House is to left.

 

[bigman68]

I've been in the concrete business for 35 years, I didn't need to go past the 1st picture, either figure major expense to fix it if possible, or tear it out and repour.

 

[sailah]

I think we all agree that the floor slab is concerning, which is why I'm asking questions. In the larger picture of the house/maritial relations/costs I can stomach doing a larger repair if necessary, hopefully down the road.

My plan was/is to shore up underneath with some 8x8 red oak beams jacked into place, essentially halving the span. I would place my tools strategically over heavy supports. Jackhammer up all the bad concrete and repour.

I have to think that doing this, and being smart about where I put tools, should at least buy me some time. In the big picture, if the floor needs to be redone, and the bill is 25-50k, it'll still be worth it. I'm not being flip about that kind of cash, but the house is beautiful and in a super nice area. And we did well on purchase price.

I appreciate all the thoughts, especially the ones saying run away!! Thanks

 

[rancherbill]

Lower your offer by $75k (the contractor above said this number) and have it replaced.

You will have the same trouble he has when you sell it later.

 

[Gotcha640]

If you have another place to keep the tools while you shore up the slab, sounds like you have an idea of what it will take to repair, and the time and money and interest to do it.

 

[Jinks]

Good looking property! If I wanted it I would consult a contractor about repair for that floor, get his pricing & bump it by 50% or 100% & reduce my offer by that amount. The owner enjoyed the property without maintaining it, so he should pay now. If not, I'd walk.

 

[LX-Markham]

^^Yeah, looks really nice in that picture.

Factor in the cost to tear-out and replace the structural slab. That one is done!

 

[sailah]

Lower your offer by $75k (the contractor above said this number) and have it replaced.

You will have the same trouble he has when you sell it later.

Understood. I already got everything I'm going to get out of the seller during negotiations, he's already taking a huge bath from what he paid + cash on renovations. He's bringing a check for $106k to closing. All indications to this point are they are tapped out and not willing to go lower and my spidey senses confirm this.

I've wrapped my head around this garage floor deal as my problem essentially. I know if I buy the house, I'll have to repair it and the bill will be sent to me.

That said, I have a lot of skills in repairing things, just not concrete. I've got a backhoe, timber framing skills, machine shop, welding equipment and a deep down desire to do things myself.

I fully understand this will be a big project in both time and money and at times I will be questioning my sanity for taking it on. But I'm stubborn and unusually resourceful so I have to think I can tackle a fair amount of the grunt work myself and bring in pros when the time comes.

If you have another place to keep the tools while you shore up the slab, sounds like you have an idea of what it will take to repair, and the time and money and interest to do it.

I do have a place for my tools, which is where they have been for awhile. Sadly I've been living in a townhouse for 8 years. I'm just trying to get a better handle on the scope of the repair and the ballpark costs.

Good looking property! If I wanted it I would consult a contractor about repair for that floor, get his pricing & bump it by 50% or 100% & reduce my offer by that amount. The owner enjoyed the property without maintaining it, so he should pay now. If not, I'd walk.

I have a concrete contractor coming by to give an estimate tomorrow. I've beaten the seller up by a lot off his asking price, so even with the figures tossed out there, I'd still be comfortable with the purchase. I'm hoping to do a lot of the work myself.

Here's a pic of the front of the house



And yard

^^Yeah, looks really nice in that picture.

Factor in the cost to tear-out and replace the structural slab. That one is done!

 

[rancherbill]

I've wrapped my head around this garage floor deal as my problem essentially. I know if I buy the house, I'll have to repair it and the bill will be sent to me.

That said, I have a lot of skills in repairing things, just not concrete. I've got a backhoe, timber framing skills, machine shop, welding equipment and a deep down desire to do things myself.

Well don't say the GJ guys didn't warn ya!!!

Just for you scheduling if a contractor says it a certain number of hours to do the job, it will take you 4 times that. Learning, not having the perfect tool, experience etc will add up.

Good luck and may the force be with you.

 

[bushmechanic]

I'm not an ancient alien, but even I can see that slab is a no-go.

 

[MoparTrucks]

Can you even get a mortgage for that?


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[sailah]

Well don't say the GJ guys didn't warn ya!!!

I've been warned haha

I'm not an ancient alien, but even I can see that slab is a no-go.

Yeah, I'm feeling that is the case.

Thanks for all the advice. I know it sounds like I'm being stubborn and everyone is telling me to run away as fast as I can. The reality is that my wife and I love the house, property and neighborhood. We've gone into it knowing that this is probably going to be expensive to fix, but it will be worth it overall.

We've been looking for over two years for a place and gotten into the dance on a couple. I told my wife that this is an old house and it's going to have problems. We are going to be surprised at times with the amount of work and money it takes to fix it, but are determined to make it work and have fun doing it.


Here's what a buddy of mine said when sent the same pics, seems like solid advice.

OK, piss poor design from the start.
Plenty of bar running the width (as car would be parked) but minimal in length.
Would be like making plywood with all grain going one direction...good strength one way and not **** the other.
Any building inspector that would have allowed that to be poured as a structural slab should be nutted.
First thing I see is no lip or rain ledge to keep water from pushing under the garage doors. Not so sure your rust damage came from the damp below, would sooner think the plastic moisture layer on the bottom trapped the water that worked down from the top via the fail lines across the width and was trapped and then froze to pop the concrete away and expose the bar.
I see a top and bottom layer of bar but would assume a center layer does not exist.
To have anything I would consider load bearing you need equal amounts of bar in both directions.
I can see some signs of minimal bar running length direction but assume just used to hold the bar running in width in even spacing for the pour and doesn't do **** for strength.
That slab should show some signs of chairs (plastic supports) showing from the bottom that would have been used to hold the lower layer a given distance from the bottom for proper position in the slab. My guess is they had the forms in place and poured a skiff layer to cover forms and then installed the lower layer of bar....poured close to the surface and installed the upper layer then finished over to final grade. That would explain the bar being uneven in position in the pour.
Pete the slab will not fall (well it will when the bar finishes rusting) because you have width tension with the bar but would not be surprised to see the remainder of the slab do the same bending load concentration. Since you have no good bar running the length no need to worry about saving good bar to attach to...it does not exist.
Best repair I could see would be saw cut width 100% depth and just remove taking rusted bar running the width with it.
Drill pockets into the remaining good slab for bar to be inserted with epoxy to seal from future moisture.
Tie two layers of bar into a mat and have supported at proper depths.
Re pour with a fiber mesh concrete, 4k minimum mix.
The idea of supports running to the existing I-beam is worthless, you need additional support running the same direction as the I-beam. At a minimum I would have one beam per center of each bay.
Existing beam looks to be in 10" range and not a H-beam so check the load rating on that beam if it was in good condition. Now you see why I mentioned using POR-15 or good epoxy on any steel support surfaces...just a home for structural rust and then failure.
The block wall that supports the beam looks to be just laid direct on the ground with no load spreading foundation (see the lower layer of blocks to the rear cut to fit).
Direct to the ground is fine for your stone wall that is massive and thick but a block is fragile and will not tolerate uneven loading of weight and then add in moist with freeze thaw factor.
Here is my question for you to think about.
What is in that lower area? I see a fuel tank. Does anything exist that can not be moved? What will you use this space for?
If mine and I wanted a proper shop / garage floor I would relocate the mechanical items and I would remove the existing slab and fill the space with crushed stone and pour and complete new slab. I would make use of the existing space by first building walls for a service pit in each bay that your vehicle would drive over....alum plate surface for when not in use. Fuel oil tank and even a waste oil tank could still be out of site....just a thought for someone that likes to wrench and doesn't have height for a lift.
Anyhow, back to the slab. I see no saving it. If you are forced to make something work and on your nickle I would first stop the moisture attack from the surface. Rent an electric jack hammer and remove anything loose...blow clean and dry...stop rust on exposed bar..build up area with floor grade grout in layers allowing cure time and skuff surface between layers. Then I would get plate steel and span the wheel travel area from entrance to existing solid area and lag the plate at each end so not to move and help from sagging to carry the load.
Below I would not bother patching in the concrete, zero structural value. Do what you can to stop future rust.
Up top I would run some water on the failed area (after you seal the cracks with grout) and drill a couple holes thru the concrete at the low points to drain the water to the lower level so not to allow time to seep back into the cracks.

 

[Chopper64]

Houses are a love hate thing. If you love it you will at some point hate it if you have to work on it. That being said since you have been looking for 2 years you obviously know what is out there and the cost associated with the ones in your area. Since you are on the East coast and the price of housing being insane (to me at least) you have to decide if it is the dream house you are looking for. If it is, fix it and enjoy it. Ultimately you are the one that has to be happy but more importantly your wife has to be happy. Looks like a real nice house in a nice area. I can see why you want to buy especially if you are getting a good deal. Remember when you are done fixing it, it is fixed and worrying about it will be a non-issue. Good luck.

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[JerryB]

I'll take a chance on jumping in here:

First, the house and property appear to be beautiful. I really do understand and appreciate your commitment to purchase it.

When compared to the rest of the property, the garage floor is relatively minor. Costly to fix correctly, but still a relatively small annoyance on what appears to be a beautiful property.

I would absolutely not try to 'fix' or 'repair' that floor. Recognize that the broken concrete and totally rusted out reinforcing steel is not limited to the places you can see. I'm certain the rest of the floor is similar: It just hasn't broken up yet. The original builder didn't do a lousy job on what is obviously destroyed, and do a good job on the parts that have not yet broken.

And, don't forget that joints between the old and new concrete will never be as strong as a continuous pour. I see some mention above of de-rusting and coating the existing rebar. I do not believe that will do much for the rebar that already looks as if it is seriously eroded by rust, and it will do nothing for the rebar you can't (yet) see. That much rust on rebar means it is probably not in good contact with the concrete it is meant to reinforce, thus you can expect more broken concrete, especially if you put heavy loads on it.

I believe the real solution is to remove the entire floor and pour a new properly designed, reinforced, mixed to specification and finished slab.

Yes, that will cost more than trying to repair what is there, but there is a big difference in the performance and lifetime you can expect.

Another thought: I would not waste time trying to shore that floor up to temporarily support several tons of machinery. That just adds to the final cost, and from the looks of the existing floor, will never make the solid, level foundation you need for machine tools.

Just my opinions as the designer / owner / builder of numerous purpose built structures.

 

[Diesel Dan]

If you are considering filling the void check the price on concrete slurry, controlled low-strength material (CLSM). Seen 16' deep pits filled with this then 12" of concrete on top so 150K lb loads can roll over.

 

[sailah]

Houses are a love hate thing.

Thanks, if it were up to me, I'd live on my boat. My wife's happiness has over-ruled common sense here.

I'll take a chance on jumping in here:

First, the house and property appear to be beautiful. I really do understand and appreciate your commitment to purchase it.

When compared to the rest of the property, the garage floor is relatively minor. Costly to fix correctly, but still a relatively small annoyance on what appears to be a beautiful property.

I would absolutely not try to 'fix' or 'repair' that floor. Recognize that the broken concrete and totally rusted out reinforcing steel is not limited to the places you can see. I'm certain the rest of the floor is similar: It just hasn't broken up yet. The original builder didn't do a lousy job on what is obviously destroyed, and do a good job on the parts that have not yet broken.

And, don't forget that joints between the old and new concrete will never be as strong as a continuous pour. I see some mention above of de-rusting and coating the existing rebar. I do not believe that will do much for the rebar that already looks as if it is seriously eroded by rust, and it will do nothing for the rebar you can't (yet) see. That much rust on rebar means it is probably not in good contact with the concrete it is meant to reinforce, thus you can expect more broken concrete, especially if you put heavy loads on it.

I believe the real solution is to remove the entire floor and pour a new properly designed, reinforced, mixed to specification and finished slab.

Yes, that will cost more than trying to repair what is there, but there is a big difference in the performance and lifetime you can expect.

Another thought: I would not waste time trying to shore that floor up to temporarily support several tons of machinery. That just adds to the final cost, and from the looks of the existing floor, will never make the solid, level foundation you need for machine tools.

Just my opinions as the designer / owner / builder of numerous purpose built structures.

Jerry excellent points and a thoughtful explanation, thanks. I agree on the proper fix. My counter to that is that the slab has been around 35 years. If I can give it some more help and get another few years out of it that would make the project much more appealing. If I can throw a band aid for $1000 at it by using wood beams it would allow me time to budget the cash to do it right.

My gut tells me this slab does have some life left in her despite what looks like a bad area of cracking. The entire back of the slab is perfect, it's just this 4' frontal area that doesn't look great.

If you are considering filling the void check the price on concrete slurry, controlled low-strength material (CLSM). Seen 16' deep pits filled with this then 12" of concrete on top so 150K lb loads can roll over.

Interesting. So how would that work? Wall off the area in the basement, fill to within 12" of deck. Pour 12" concrete on top of that to get to finished height?

Just playing with numbers here. 25x20 garage and say 7' deep although I suspect it's probably 8' to deck height?

so say I fill it with flowable fill call it 25x20x7 or 130 yards @ $75/yard
Then 25x20x12" concrete on top or 19 yards of concrete @ $100/yard

That's $12,000 in concrete. Obviously I have other costs in there to form up the walls to hold everything, rebar and a bunch of other stuff I know I'm missing.

Would doing it this way be cheaper than another suspended slab? Don't know but I like the data point.

Here's a quick sketch I did for a way to shore up the floor in the mean time, the timbers are all sized so that I could muscle them in place solo or with minimal help. 8x8 pine is $0.75/bf here. Lap joint and support with posts on small footers, jack into place. I think that would be tremendously strong and buy me time to get the right fix in place. I would plate each joint and lag the timbers to the slab with angle to hold in place.

Open for ridicule

 

[Git]

Your thinking of spending $1.3 million on that house and your balking at having it fixed properly?

http://www.weichert.com/57186236/?GCID=C10566x300

http://www.zillow.com/homes/632-Main-Street-Hingham,-MA-02043_rb/

 

[gregtwojeeps]

I hate being the rain during the parade but someone has to... A little "sky is falling rhetoric" follows...

Just keep in mind....there is nothing that cannot be repaired on any residence or property. All it takes is the money to do it. Also remember that life and good health is not guaranteed to us for one more day. If God forbid, something happens to you, will your financial situation left behind.... enable your family to survive with a defective piece of property they would have to sell for a loss ? What if you fall sick in the middle of a floor restore ? Anyone to take over ?

If you can answer these questions to yourself honestly with a positive answer.... go for it, its just money. It is a beautiful place. All jmo.

 

[bushmechanic]

I'll take a chance on jumping in here:

From the looks of those pictures, this is the last place you should be jumping.

 

[sailah]

I hate being the rain during the parade but someone has to... A little "sky is falling rhetoric" follows...

Just keep in mind....there is nothing that cannot be repaired on any residence or property. All it takes is the money to do it. Also remember that life and good health is not guaranteed to us for one more day. If God forbid, something happens to you, will your financial situation left behind.... enable your family to survive with a defective piece of property they would have to sell for a loss ? What if you fall sick in the middle of a floor restore ? Anyone to take over ?

If you can answer these questions to yourself honestly with a positive answer.... go for it, its just money. It is a beautiful place. All jmo.

I'm 37, in good health. My family would be fine, I've made sure of that.

From the looks of those pictures, this is the last place you should be jumping.

 

[bushmechanic]

Your thinking of spending $1.3 million on that house and your balking at having it fixed properly?

If I were shopping, the state of that slab wouldn't fall into the financial category, it would fall into the "it ain't never gonna be right unless half the house is shut down for several months, and even then it ain't never gonna be right" category.

If you're going to spend that much, wouldn't you want to know whether something can be fixed or not, and what it might take?

Hell, buying a house like that and tearing it apart to get it right kind of takes the sweet out of the sugar.

Either way, nobody ends up in that ballpark without a history of well calculated purchase decisions. I'd say all the concerns and questions are well-founded.

Yes, that last sentence is meant to be a pun.

 

[bushmechanic]

That said, if you are really feeling that house, it could very well be worth the trouble to fix it. Just be sure the rest of the place isn't as poorly planned.

A rusty floor pan isn't always enough to keep you out of buying a car. Most of the time it should be, but sometimes, sometimes, you just know it's the right car.

 

[sailah]

Your thinking of spending $1.3 million on that house and your balking at having it fixed properly?

http://www.weichert.com/57186236/?GCID=C10566x300

http://www.zillow.com/homes/632-Main-Street-Hingham,-MA-02043_rb/

I'm not balking at fixing it. I'm asking for opinions about the correct way to do it. As of this morning I knew almost nothing about concrete. Thanks to the generosity of others sharing their ideas I now know a lot more.

I'm able to afford things because I stretch dollars and do it myself. Being a business owners teaches you where to spend the money and when to save. I'm not ashamed to have nice things and I work hard to get them.

I spent 12 hours over the weekend grinding rust off an equipment trailer I paid $700 for instead of dropping $6000 on a new one. I could afford a new trailer but I'm happy to save the cash. I also have a 10 year old truck with 115k miles on it. I change my own oil, do my own brakes. I have zero debt, other than this impending mortgage thanks to your curiosity is now on public display.

 

[tab2]

The housing market across our state is extremely competitive right now and you have a very desirable town. One that I hope to be able to move to after moving out of the city. Houses are selling within days that have multiple offers above asking. Congratulations on getting this far.

Flowable (concrete) fill is much less expensive than what you have estimated (a sub of mine quoted me around 50/yard to fill an old indoor swimming pool). It would be one way to deal with this and what I would believe to be the best if you don't want the space down there but it looks like you would need to relocate some plumbing and an oil tank.

I don't think this should be a deal breaker as long as you are prepared for it which it seems you are. Good luck and please keep us updated.

 

[sailah]

The housing market across our state is extremely competitive right now and you have a very desirable town. One that I hope to be able to move to after moving out of the city. Houses are selling within days that have multiple offers above asking. Congratulations on getting this far.

Flowable (concrete) fill is much less expensive than what you have estimated (a sub of mine quoted me around 50/yard to fill an old indoor swimming pool). It would be one way to deal with this and what I would believe to be the best if you don't want the space down there but it looks like you would need to relocate some plumbing and an oil tank.

I don't think this should be a deal breaker as long as you are prepared for it which it seems you are. Good luck and please keep us updated.

Hey that's the best news I've heard all day! Your welcome to stop by when I'm moved in, just don't stand on the garage floor.

 

[Diesel Dan]

Interesting. So how would that work? Wall off the area in the basement, fill to within 12" of deck. Pour 12" concrete on top of that to get to finished height?

Yes but you'd only need a 4-6" concrete deck.
We have 12" for extreme weight.

 

[Jinks]

sailah, since reading through your entire thread, your responses, & your attitude about taking on a job, it looks to me like you've made your decision. You have gotten some good ideas on various ways to proceed so let me be among the first to congratulate you on a beautiful new place.

Don't be afraid to tackle a job you've planed for financially. I invested 1.5 times the purchase price of our current house to strip it to bare framing, remodel, & add a second story. Most would say "a waste of money", or "why not build new", but we ended with a better home than we could have built in the location we wanted. It was all worth it!

 

[barks]

1. Remove slab
2. Construct proper support using iron or timber structures
3. Place new floor using timbers

 

[MoonRise]

Entire slab is ****.

The concrete is deteriorating (badly) and the rebar is deteriorating badly (as well as not being placed properly to begin with!).

The 'fix' is to remove the entire crappy slab and redo it completely. IMNSHO.

As to trying to 'shore up' the crumbling, cracking, and deteriorating existing slab with some wooden oak beams?

Nope. Concrete/masonry is always to be considered 'wet'.

Oak wood against 'wet' masonry = rotten wood

Can it be 'fixed'? Sure, with enough money to rip it all out and redo it properly. As well as possibly the rubbblestone/fieldstone and brick 'foundation' walls there (enough bearing support there or not?) Possible need to jack the entire structure off the foundation (doable, but $$$), rip out the slab and iffy foundation, redo foundation, redo slab, reset building on new 'proper' slab.

All doable, not rocket science or brain surgery, but certainly a rather big chunk of time and money to fix. As well as the time and money of all the required permitting to go and fix the crappy job that the original permitting and 'inspections' let happen in the first place! Hope Taxachusetts doesn't require some 'other' stuff to go along with everything else going on there (mention of possible fuel oil tank there, possible ground 'contamination' requiring $$$ removal of dirt and so forth, etc)

Let us know what happens.

 

[rancherbill]

My wife's happiness has over-ruled common sense here.

I can understand nobody's happy unless Momma is happy.

Just make sure she understands this repair is coming out of her shoe budget not your budget!

Put your foot down right from the start.

 

[Krash Kadillak]

Based on the pics, I would guess the garage was actually the original house on the property, then remodeled into the garage when the new house was built out front. Your 'crawl space' under the slab was the root cellar..... It probably had post and beams in it prior to the slab floor getting poured.

And what did the engineer say when you told him the weights of your woodworking equipment?