I've got a guy from a reputable local firm coming out here Monday afternoon, but I thought I'd pass this by the collective to see if anybody had any idea of just what we're facing and how expensive it's likely to be.

Several years ago I noticed this downspout, the end of which originally slotted nicely over the end of the elbow at the bottom, wasn't any more.



"Garage is sinking?" I asked myself. But it didn't appear to be, because the foundation was still high & dry. "Hmmm..."

Next thing I noticed was a gap forming in the vinyl siding above the garage door.



When we had the roof replaced three seasons ago, the on-site project manager noted "You have something going on with your garage. You need to get somebody out here to address it," and pointed to that gap as just one indication of his concern.

Straightening out the interior early this last winter, I noticed this:



That's the end of a pair of end-to-end long boards that stretches width-ways across the middle of the garage from the house to the outside wall of the garage.

"Ok," I thought to myself, "no putting this off any longer. As soon as spring gets here, I'm getting on this."

Look out the family room window, this afternoon, and notice this:



There always was a bit of a "bump" in that soffit line, but not that bad!

Look inside and see:



That's the end of one of the rafters that runs from the front of the garage to the back. It's barely on the sill, any more.

My wife and one of our next door neighbours thinks it's all because the garage floor is sinking. And it's true that there's a height difference between the two slabs (maybe 1/4"?) that I don't think used to be there.

The guy that's coming out Monday asked about the width of our garage door and what was the header. When I told him "18 feet" and "2x12," respectively, he said that's almost certainly the main culprit and that, if the garage floor were sinking, it'd be heaved and have large cracks in it. Said even sistered 2x12s wouldn't be enough for that span. That an engineered header was needed.

So what say SF's construction gurus? What're we lookin' at, here, and how badly are our finances gonna be nicked?

And, yes, I know: I've been remiss and should not have put this off like I have.

Not a construction engineer, but an old house I lived in had a garage that had similar problems. I was told it was because the foundation was settling. My landlord had it torn down and rebuilt a new garage in its place.

I'm not an engineer or even in the construction industry. But my mothers CBS house had this issue in a bedroom on the corner of the house. They ended up pumping concrete under the foundation to stabilize it. As for the garage header, perhaps you can go to a steel beam for the header and that would be much stronger than a wood 2"x12". It is most likely fixable, but without having a ground survey and eyes on it, the fix is not easy to identify.

Yeah, in my old “boathouse” ( really a detached garage) the inspector said I had to use engineered beams for distances over 12 feet....the front was 24 feet. I used a beam over the front where an overhang was planned, but used sistered 2x’s for over the garage openings.

I imagine that’s your problem

I’ve just been watching a bunch of shows about sinkholes, so I’m thinking sinkhole!

If your garage ends up disappearing into a very deep, very large pit that opens like the mouth of hell (minus the fire) directly under your house, that would be a good clue that it’s a sinkhole causing these problems.

Hope that helps.

-Rob

Thanks for the follow-ups, guys, even if y'all aren't construction experts

My current thinking is it's likely a combination of the foundation settling--perhaps brought on by our adding gutters, along with downspouts that kick out about four feet or so, and the garage door header.

So probably going to require both that header being replaced with an engineered beam and mud jacking--as well as other structural corrective measures.

quote:

Originally posted by BurtonRW:
I’ve just been watching a bunch of shows about sinkholes, so I’m thinking sinkhole!

I realize that's probably meant to be a humorous comment, but a sinkhole is unlikely.

Despite the fact the USGS soil survey claimed the area was primarily "sandy loam," it turns out we're on clay. Lots and lots of fracking gorram clay. When they drilled our new well a number of years ago, well guy said "brown clay for about <murfl> feet, then straight to blue clay all the way down to the aquifer."

That is, except where there are stones or rocks.

I think you need a second and maybe third opinion.

I am just a layman, but have closely participated in the building of 4 personal homes and 4 office buildings, and worked for a builder for a while in college- all in an area where the soil is a serious issue and foundations must be over-engineered to be successful.

When I look at your pictures, I am thinking foundation. Under-spec'ed joists aren't going to create those kinds of problems.

Disclaimer: My opinion is worth exactly what you have paid for it.



.

quote:

Originally posted by TigerDore:
I think you need a second and maybe third opinion.

I don't even have the first opinion, yet.

quote:

Originally posted by TigerDore:
When I look at your pictures, I am thinking foundation. Under-spec'ed joists aren't going to create those kinds of problems.

Foundation isn't going to cause sags in the middle, either, and there is definitely sagging going on. That was evident even 15-20 years ago, when the gutters were installed, and they couldn't make the front gutter work quite right because of the sag in the middle. So I knew, even back then, that someday I'd have to address that.

I figured Arc would be along by now. He seems expert at this stuff. Was hoping to learn from him on this.

No structural engineer here, but I can say I'm glad you are now fully engaged, and that it's held together.

Might be premature till cause and remediation are known, but how much of this do you think might be covered by insurance?

quote:

Originally posted by joel9507:
Might be premature till cause and remediation are known, but how much of this do you think might be covered by insurance?

I hadn't really expected any of it would be covered by insurance. Hmmm...

Not a pro either but I'm sorry you've got to face this issue.

I live in Central Texas and the blackland soil constantly expands and contracts, causing significant issues for foundations. Depending on the time of year and ground saturation, I've got doors that will not open/close.

The separate slab leading into our garage has gone to pieces.

It sucks because there's no cheap fix to any of it.

I wish you luck!

quote:

Originally posted by darthfuster:
I figured Arc would be along by now. He seems expert at this stuff. Was hoping to learn from him on this.

I only saw it today on my phone, had to wait to get home to a large screen.

Vinyl expands and contracts significantly, and it typically is overlapped an inch or more. That gap means they butt it, and it settled out. Or it's something else which I'll get to.

A Double 2x12 is undersized for 18' in that application, on paper. But I've seen a lot of undersized construction survive. It just can't be _too_ undersized. Building codes are a good guideline for sure, but local conditions mean some things survive.

You can certainly submit to home insurance, they'll entertain repair, because if it collapses, the contents will need to be replaced.

The undersized beam over the door is not a huge deal, you can jack the roof off and replace it with an LVL, or make a Flitch Beam out of it.

Does the garage actually have a small foundation? Or is it slab on grade? Soil settling could be a factor, but lots of old buildings aren't plumb and square, so..


The "sill" you describe is the double top plate of the garage wall, with the rafter coming down, and a "joist" that is barely hanging on..

So, my caveat being that an in person look would be best, but here is what I see. With a garage door that is 18' open span, and a low slope roof that looks like 2x4 rafters, I have to ask, how is the snow load each year on this thing? Hopefully everything is at least 2x6.

The "joist" going across the garage, should not be the only triangular support for the roof rafter, there should be a midspan and ridge support. This is to resist the down force of the roof being turned into outward force against the wall top plate. What you should see is the rafter nailed directly to that joist, as well as toed to the top plate. Looks like they didn't connect the joists and rafters...

How old is the garage? My feeling is that while the roof appears underframed, it may be incorrectly framed in that the roof pushes down when loaded, and is spreading the walls apart. Are the walls still plumb? Soil movement could be an additional factor, but the low slope of the roof and separation at the top plate stands out. The roof also has a ripple in it, and those gutters look like that typically due to icing.

I would put a level on the walls, and if they are leaning out at the top, away from the roof, well, bingo. That would mean you're a few good snow storms away from listening to your garage roof crush the contents, some wintery night.

There are things that can be done without building a new garage, but I wouldn't wait another winter. If I'm wrong about snow in Michigan, then it's not a problem, but I think the main culprit is snow sitting on a low slope garage, with a roof that doesn't have adequate triangular bracing.

It can all be jacked off, and corrected, probably. Headloks and Simpson ties are wonderful products. As far as the 18' open span 2x12, it needs a laser on it to see how deep the middle is, and then evaluate additional structural adds.

So, in summary, maybe the ground/foundation/slab is a factor, but it's not where I'd look first. Look at the walls. In lots of old structures, the roof pushes the walls out over time, as things shrink and bend. 1/4" to 1/2" out, meh. But you've got framing separating, I think you'll find more, and too much.

Because of your location I'm thinking snow load, and that the garage is unheated, and maybe if you do rake the roof it doesn't happen a lot, or the previous owner didn't.

I could be wrong, but check those walls for plumb.

If you don’t see large cracks on the concrete floor, or other signs of differential settlement. I would look at the load path as Arc has suggested. Look at your rafters, are they a truss construction or a rafter with a collar tie. The thing I have seen overlooked the most in designs is lateral loads placed on large openings.

(2) SPF 2x12s are way undersized for a 18’ span, to a point that makes me wonder about the gravity load path. Is your garage opening located an end wall, or sidewalk of your home?

Just be mindful you can ask 10 engineers the same question, and get 10 different responses.

quote:

Originally posted by RespectTheAmish:
If you don’t see large cracks on the concrete floor, or other signs of differential settlement. I would look at the load path as Arc has suggested. Look at your rafters, are they a truss construction or a rafter with a collar tie. The thing I have seen overlooked the most in designs is lateral loads placed on large openings.

(2) SPF 2x12s are way undersized for a 18’ span, to a point that makes me wonder about the gravity load path. Is your garage opening located an end wall, or sidewalk of your home?

Just be mindful you can ask 10 engineers the same question, and get 10 11 different responses.

FIFY

quote:

Originally posted by TigerDore:
I think you need a second and maybe third opinion.

I am just a layman, but have closely participated in the building of 4 personal homes and 4 office buildings, and worked for a builder for a while in college- all in an area where the soil is a serious issue and foundations must be over-engineered to be successful.

When I look at your pictures, I am thinking foundation. Under-spec'ed joists aren't going to create those kinds of problems.

Disclaimer: My opinion is worth exactly what you have paid for it.



.

More opinions wouldn't hurt, in fact you may feel better about fixing this if two opinions are pretty much the same.
Also, using "engineered wood beams" is something I'd consider. Supposedly weigh less than a steel beam and with a roof weight is your enemy.

quote:

Originally posted by arcwelder76:

quote:

Originally posted by darthfuster:
I figured Arc would be along by now. He seems expert at this stuff. Was hoping to learn from him on this.

I only saw it today on my phone, had to wait to get home to a large screen.

ISTR you work for a living

Btw: Before I go any further, I should probably have noted it's a hip roof.

quote:

Originally posted by arcwelder76:
Vinyl expands and contracts significantly, and it typically is overlapped an inch or more. That gap means they butt it, and it settled out. Or it's something else which I'll get to.

That gap has been steadily growing for a number of years, now. I've been remiss in addressing it.

quote:

Originally posted by arcwelder76:
You can certainly submit to home insurance, they'll entertain repair, because if it collapses, the contents will need to be replaced.

I'll talk to them about it.

quote:

Originally posted by arcwelder76:
The undersized beam over the door is not a huge deal, you can jack the roof off and replace it with an LVL, or make a Flitch Beam out of it.

The contractor we have coming out tomorrow mentioned an engineered beam.

quote:

Originally posted by arcwelder76:
Does the garage actually have a small foundation? Or is it slab on grade? Soil settling could be a factor, but lots of old buildings aren't plumb and square, so..

I honestly do not know, as I've never dug down to find out.

quote:

Originally posted by arcwelder76:
The "sill" you describe is the double top plate of the garage wall, with the rafter coming down, and a "joist" that is barely hanging on..

Yeah, got my terminology all jacked around.

Oh, and that joist has significant sag in it, too.

quote:

Originally posted by arcwelder76:
So, my caveat being that an in person look would be best, but here is what I see. With a garage door that is 18' open span, and a low slope roof that looks like 2x4 rafters, I have to ask, how is the snow load each year on this thing? Hopefully everything is at least 2x6.

Yes: Everything except the wall studs and top plates are 2x6 or better.

quote:

Originally posted by arcwelder76:
Looks like they didn't connect the joists and rafters...

Well... they kinda sorta did, but not in the way you describe. Furthermore, with what you're saying, I think probably I made matters worse by putting a pair of 4x8' sheets of plywood across those joists and using the space for storage.

Plus I've a pile of wood leaning against the outside wall away from the house.

quote:

Originally posted by arcwelder76:
How old is the garage?

I do not know. I suspect that, because of what looks like different-coloured wood in different parts, and some of it looking definitely like recycled lumber, that it was a 1-1/2 car garage extended to a 2+ car garage. If so: The original homeowner did it, and, IME: He couldn't do something straight or right to save his soul.

quote:

Originally posted by arcwelder76:
My feeling is that while the roof appears underframed, it may be incorrectly framed in that the roof pushes down when loaded, and is spreading the walls apart. Are the walls still plumb?

Amazing how the simplest thing to check can escape our attention, sometimes, isn't it? No, they are not. (See below.)

quote:

Originally posted by arcwelder76:
... and those gutters look like that typically due to icing.

There's never any icing to speak of in or on that particular gutter.

quote:

Originally posted by arcwelder76:
I would put a level on the walls, and if they are leaning out at the top, away from the roof, well, bingo. That would mean you're a few good snow storms away from listening to your garage roof crush the contents, some wintery night.

First three photos are the back wall. Next three are the side wall away from the house (the perspective isn't the same on them all, but they're all leaning out):

quote:

Originally posted by arcwelder76:
There are things that can be done without building a new garage, but I wouldn't wait another winter. If I'm wrong about snow in Michigan, ...

You're not and I won't. We didn't have all that much snow, this last winter, but we have in winters past.

quote:

Originally posted by arcwelder76:
As far as the 18' open span 2x12, it needs a laser on it to see how deep the middle is, and then evaluate additional structural adds.

It has sagged badly enough you can clearly see it from inside the garage.

quote:

Originally posted by arcwelder76:
Because of your location I'm thinking snow load, and that the garage is unheated, and maybe if you do rake the roof it doesn't happen a lot, or the previous owner didn't.

I used to rake the roof, but, after the re-shingling a few years ago, where they installed a Tyvec-type "felt" and snow and ice shield 3' back from the walls, it seemed no longer necessary. Plus I never got much in the way of ice dams on the garage, anyway--which was the main reason I used to rake the roof.

quote:

Originally posted by arcwelder76:
I could be wrong, but check those walls for plumb.

Done and they're not.

Thanks for your expert insights, Arc!

quote:

Originally posted by RespectTheAmish:
If you don’t see large cracks on the concrete floor, or other signs of differential settlement.

There are no cracks at all. Not even little ones.

quote:

Originally posted by RespectTheAmish:
(2) SPF 2x12s are way undersized for a 18’ span, to a point that makes me wonder about the gravity load path. Is your garage opening located an end wall, or sidewalk of your home?

Sidewall, maybe?

It's an attached garage, one wall, adjacent to the garage door opening, of which is one wall of the house.

quote:

Originally posted by RespectTheAmish:
Just be mindful you can ask 10 engineers the same question, and get 10 different responses.

Yeah, we're trying to find other well-reviewed local contractors we can have come out for a 2nd or 3rd opinion and quote.

Thanks for the feedback, RTA!

quote:

Originally posted by ensigmatic:

quote:

Originally posted by TigerDore:
I think you need a second and maybe third opinion.

I don't even have the first opinion, yet.

quote:

Originally posted by TigerDore:
When I look at your pictures, I am thinking foundation. Under-spec'ed joists aren't going to create those kinds of problems.

Foundation isn't going to cause sags in the middle, either, and there is definitely sagging going on. That was evident even 15-20 years ago, when the gutters were installed, and they couldn't make the front gutter work quite right because of the sag in the middle. So I knew, even back then, that someday I'd have to address that.

I forgot about the snow load up there, as arc mentioned. It makes sense now. Good luck with the repair.



.

Got the first ball-park estimate for fixing the garage: $8,000 to $9,000.

Arc called it: Improper construction is causing the roof to push the walls out. If it's not corrected, and relatively soon, the whole thing will eventually come crashing down.

The builder concurred with my guess that it was originally a 1-1/2 car garage improperly expanded to be a two+ car garage.

I'm going to have to empty the entire garage for them to get it done. That, in itself, will be a non-trivial undertaking.

He gave me a couple suggestions on things to do to slow further degradation until the repair can start.

And, yeah: It's so bad that it would almost be worth knocking it down and building a new one. But we just had $8,000+ worth of new roofing put on a couple of summers ago and all the electrical and communications service entrances are on the garage's back wall.

We liked the guy that came out, but we're still trying to qualify another firm to get a second opinion.

Good news is the foundation/pad seems to be fine, as I thought.

I haven't talked to our homeowner's insurance company yet, as our agent was out today.

Update

Consulted with one of my next door neighbours, who, while not a professional construction type, is quite experienced in building things.

"Nonsense," was his reaction. His recommendation: Take the pressure off the walls a bit with a jack under the center beam of the roof, use a pair of come-alongs to bring the walls back in, re-anchor/-attach the joists that came loose, add the missing joists, done.

He also pointed out the header is not sagging. Put a level on it in several places. Walked outside and looked. Showed us how the appearance of it sagging is an optical illusion.