Garage Sinkhole: A Joyous Celebration

When I first started writing about my garage project, I mentioned that I was about 80% sure that our garage was slowly sinking into a sinkhole. I couldn’t be certain, of course, but several signs indicated that there was active soil movement on the property, but now I have certain proof.

Last time I wrote about the project, I showed that we had used a circular saw to cut away the asphalt in front of the garage so that we could have some room to pour a concrete apron. When I last posted a picture, it looked like this:

Straight asphalt edge.

Since that photo was taken, we dug out about 6-8 inches of dirt to provide a space to pour the concrete apron. We finished digging last weekend, and had started to set the forms for pouring the concrete. We had the concrete bed all flattened and compacted ready for concrete. Then Tuesday evening we had an ever-so-slight rainfall. Really, just a tiny bit of rain. We woke up Wednesday morning to find that this sinkhole had opened up right next to our garage, completely undermining our brand new slab:

Garage Sinkhole.
We’re doomed.

And if that much movement is happening with the slightest bit of rain, who know what’s happening when the rain really starts moving. It  confirms, though, that we’re building a garage on top of an active sinkhole. There is about a 0% chance that this will end well.

But this is not a sad post, friends. This is cause for joyous celebration. Right now, as you’re reading this, I want you to feel smart and capable. I want you to feel proud of your accomplishments. I want you to celebrate your successes.

As we move through life, each of us will make mistakes. We will have setbacks and challenges. We will underperform, miscalculate, or neglect some important thing. We will beat ourselves up over it. We will have feelings of self-doubt or shame. And next time, dear reader, you start beating yourself up over your latest failing of some sort, I want you to stop, think of this post, and smile. No matter what you’ve just screwed up, you should take immense comfort in knowing that at least you aren’t that guy on the internet who built a brand new garage on top of a sinkhole.

Garage Slab Forms

Well, there’s been a bit of progress on the garage project this past week. If you recall, we decided to hire out the slab work to someone else. After much waiting, they finally had time to come start the project.

We went from this:


To this:

Forms ready for inspection.

It took a pretty good size load of fill material to get this leveled out at the right elevation. The new garage is going to sit a bit higher than the old one. We’re using 12″x12″ footers rather than the minimum required 4″x8″ just to beef things up a bit. We’re also using #4 rebar at 2′ on center rather than a more typical 4′ on center, and a 5″ slab rather than a more typical 4″ slab, also just to beef things up. We’re also gonna use a fancy-schmancy 4500 psi concrete with microfiber just to make sure this thing is solid since there may or may not be a sinkhole underneath.

“Bring it on, sinkhole,” I say tauntingly. “Open up under my garage. I’m just gonna bridge over you.”

Actually, I’m pretty sure that if there’s an active sinkhole under here, I’m probably screwed no matter what.

Now if that darned city inspector would hurry up and inspect the thing, we’d have a slab already.

The last time anyone will see this garage

A while back, I reported that I was pretty sure my garage was slowly falling into a sinkhole, and I asked y’all for some advice on what to do about it. The comments were 100% in favor of complete teardown and rebuild. I was teetering between a few options (including a couple I didn’t write about in the last post) that would allow us to be happy with the existing structure. But after a lot of hand-wringing and number crunching, we’ve decided to take your advice and just build a new garage.

We’ll be doing a lot of the work ourselves (and accepting a lot of help from family/friends), but we’re also hiring out some of the hardest and most critical parts. We’re hiring out demo and disposal of the old garage, just because we simply don’t have the man-power or equipment necessary to dispose of all the rubble. We’re also hiring out pouring the new foundation. I know just enough about concrete to know that I should leave it to the professionals when high-quality work is important. Since having a  square, level foundation is critical to making sure the whole garage goes together correctly, we’re just more comfortable having someone else do it.

We will handle all the framing and finish work ourselves. No, we’ve never done it before. No, we don’t really know how. But we’re gonna give it a shot anyway.

So take a good look at the photos below. This is the last time anyone will ever see this old garage. Tomorrow morning at 7:00 AM, some folks will be here to tear this poor lump of sadness down (hopefully without knocking down the neighbors garage along with it. If everything goes according to plan, by the end of the day Tuesday, this will just be an open patch of dirt.

So long, friend.
Not so bad from this angle.
Gable end.

I’m actually really excited to see what’s underneath this thing… Sinkhole? Underground cavern? Spelunking adventure? Muck? Pirate’s booty?

Probably just dirt.

Anyone want that satellite dish on top? It’s free so long as you remove it before 7:00 AM tomorrow morning.

Garage Sinkhole

I am about 80% certain our garage is slowly falling into a sinkhole.

You remember our sad-looking garage, right? Unfortunately, I believe the garage overheard me telling my wife that I liked her curves, and got the wrong idea. This is not what I had in mind.

Sad Garage

The truth is that I don’t really mind our wonky garage. I couldn’t care less that the roof is sagging or that the walls aren’t plumb. What drives me batty, though, is the cracked and sloping concrete slab inside the garage. You can tell from the sagging eaves that the side entry door is the low-point for the entire structure.

Enter: Sinkhole.

Maybe. It’s sunk at least 6″, if not a full foot right under that door, and since the whole yard drains to that point, we get up to 6″ of standing water at that point. This past winter, the bottom of the door was underwater, so whenever the water would freeze, the door would also be frozen in place. Take a look at this slab:

Cracked Slab - Sinkhole?
Cracked Slab - Sinkhole?

I dunno. I think there may be a soils stability problem. The slab just seems to have sunk too much for this to be typical soils consolidation and settling.

The sad part about this is that the timber structure is actually still in great shape, considering the terrible condition of the foundation. Seems like a shame to tear down the whole garage just because I don’t like the sloping floors… but I’m tired of setting the lawn mower on one side and watching it roll across the garage to the low point.

We’ve considered a half-dozen options, but we’ve narrowed it down to the following:

1) Jack the sunken side of the building up into (sort of) place, and pour a new slab right over the top of the existing slab. Pros: this would be cheap, relatively easy, and would solve my primary complaint (the sloping floor). Cons: this wouldn’t pass muster with any sort of building code, and is only a temporary fix. A big unknown is exactly how much life we’d get out of the new slab before it looked just like the old slab. 1 year? 5 years?

2) Full tear-down and rebuild.  Pros: new, bigger, meets building codes. Cons: cost, have to deal with permits, very time consuming; if there is a sinkhole or soils issue, fixing it correctly could be a major can of worms I don’t want to open.

Hmm… what do you think? quick fix or expensive fix?