Oh, the things we'll do...

[mulberryworks]

I've been absent from the forum for a bit because I've been digging holes in my driveway.

Living in Austin, the sun can be brutal year round and there are occasional hail storms that cause major damage. Last year the BMW dealer in San Antonio had several hundred cars damaged in a major hail storm. It was a sight to see but we didn't take the opportunity to pick up any bargains.

Anyway, I've bought a large metal carport from a Canadian company and had a local engineer draw up plans for the footings. I feel that the seller should be been a bit more forthcoming about just what was needed to keep a carport of that size anchored, but having paid for and received the carport, I don't have many options except to proceed.

There are 10 posts, and in a 95 mile an hour wind, each one could have an upward pull of 2500 pounds and so needs a footer that's 3' 3'' on a side, 15" thick sunk to a depth of 4'. The post supports are 12" columns all with #4 rebar. So, since I am putting this next to the house, that means I had to jackhammer 3'x3' holes in the concrete driveway and then dig a 4' deep hole. All that needs about 15,000 pounds of concrete mix which is now sitting in my garage.

You may wonder why I don't hire this work out. Good question. I called three foundation companies who came to look at the project. Only one bothered to give me an estimate and that was for 2 1/2 times the cost of the carport itself. Or to put it another way, almost the price of the new Honda CRV sitting in the driveway waiting for its carport cover. There's a continuing construction boom in Austin and it's hard to find contractors at any price, so they get to charge what they want.

So, being a handy sort of fellow, I grabbed a shovel. I hope to be done in a few weeks with the foundations. I've got four footings poured so far. Then the assembly of the carport should be pretty straightforward. Kinda like an Erector Set, if you remember those. All bolted together. Fun!

Then I'll be back to thinking about E9 restoration....

 

[Markos]

Love your projects Ian! Although I didn’t do it for my concrete counter tops or my deck footings, I have been advised to rent a small mixer. I use a very large wheel barrow. I poured 4 separate 8 cubic foot footings for my deck. Lots of mixing.

How is the digging in Austin? My gosh I have dug so many large holes in my yard, my neighbors must think I’m hiding bodies. I’m my neighborhood there is so much glacial till that you can’t sink a shovel into the ground without hitting baseball to basketball sized rocks.

 

[autokunst]

There's a continuing construction boom in Austin and it's hard to find contractors at any price, so they get to charge what they want.

The shortage of labor (skilled or otherwise) is prevalent in more places than Austin. It is obscene, and affecting my business let alone any projects I would like to do for myself. We have plans for a nice, new, large garage perfect for tackling the chassis restoration of the Raven - but in this market I can't afford to build it. We're saving, and waiting for the crash. Then - hopefully - construction companies will be a bit more hungry. Good luck with those piers.

 

[dang]

Wow, those peers do seem extremely large. Our engineered 4400sqft building called out peers about half that size, in CA, where it gets a little windy from time to time. Okay, never mind. Great looking project! Maybe you can add a second story on it in the future.

 

[Gransin]

The satisfaction of doing the work yourself - and succeed, is quite nice! Looking good

 

[Markos]

The satisfaction of doing the work yourself - and succeed, is quite nice! Looking good

That is only true when the finished product looks like *your garage or *your car!

 

[mulberryworks]

The reason the footings are so large is that there isn't much weight on them to counteract the uplift of a strong wind. In reality, since the house is on the high side of the carport, wind can't enter from there and there's a half wall with a fence on top at the rear that will block the wind somewhat as well so I don't think it will ever see those kinds of uplift numbers. The engineer actually used 105 mph for his calculations vs the 95 mph the carport maker used. Not sure why, but failure of the foundation will be the least of my worries if a tornado comes by.

We have had some strong straight-line winds here in the 4 years we've been in this house. Houses higher up on the hill that have taken the full brunt of 75+ mph gusts have lost sections of their roofs or had some of the Hardiboard siding pulled off their house. Part of this is due to construction that isn't quite up to par with smaller and fewer fasteners that should have been installed but the fact remains we do get some strong gusts sometimes. The carport acts like a wing and I certainly don't want it taking off.

Below is a photo of a neighbor's house showing wind damage. The stub wall used to stand next to the front door point towards the camera. The wind blew it onto the carport roof. There is an identical house just down the street that suffered exactly the same damage the same night. Both houses are 10 years old. Poor design. The foot of the wall should have been anchored to the concrete for starters.

I'm using an electric mixer borrowed from a neighbor for the concrete. Add a gallon of water, then two 60# bags (easier to handle than the 90#) of Quickcrete, let it mix for a minute, dump it out. Easy. I have bought 290 bags. Oy. Good thing I'm reasonably fit for my 60 years.

Diggin here is ok, Most of the soil is clay with little rock. Digging on Maui was hell, pretty much all rock. I grew up in Missouri, which isn't bad, some rock, some clay, mostly not a bad mix. Here there is so much clay that there's a good amount of ground movement as it gets wet and then dries out. Foundation cracking is common. Another reason for the footings to be 4' deep.

Another reason I'm doing this myself is that there's a gas line that runs next to the far side of the driveway and I'll have to be very careful when I dig that up. Yes, I've make the call and the guy located the line. I've already hand dug to actually see where it is in a couple of spots. There's enough room to do the footers. I did the most tricky one first as a test. There the line actually runs under where the post needs to be, but I made a column that does a dog leg around the gas line. Designed by the engineer, so it's ok.
The close spacing for the rest means I have to use a 2' wide slot to dig the 3' wide footer, but that's doable.

Back to it.

 

[Markos]

BTW, you can smack the crap out of a 3” gas line without putting a dent in it. You don’t really need to tip toe when hand digging. When I trenched my driveway I found a large root growing around the line. The gas company came out and just hacked at it with a sledge hammer and a shovel. I was rather astonished.

The diameter of the in question is at least 10' The root that encased the gas line is a good 8" or so...

 

[JayWltrs]

My aunt & uncle just sold their Onion Creek house for a retirement condo nearer to downtown. This year was relatively calm in OKC, but insurers have forced all the new dealers to put cars under tents or covers in the last 5 years. My old outside truck has become my dent removal practice subject. That's some pretty loamy soil, but anything is better than oppressive red dirt. Here's sewer replacement down to 14' this summer before backyard & driveway renovations:

 

[mulberryworks]

Oy. I remember replacing a sewer line in Missouri that was about that far down. Even with bracing the walls, I was not having fun. Old clay line had collapsed.

What is the red soil like? Is it a clay soil as well?

 

[JayWltrs]

It stains. When it dries out, it gets inside and on your cars, then hydrates and sticks. When it gets wet, it stains concrete, driveways, sidewalks, sides of homes, as you can see on the wall (now replaced) in the back. It can also be more like clay than dirt, which is a problem for structures, foundations, etc. when periods of drought are followed by heavy rain. Topsoil is key--see "dustbowl." Often it can be a benefit in excavation like this, because it doesn't sheer as readily. Unfortunately, we discovered an old abandoned water line had been slowly weeping into this area trapped by the house, driveway and patio (forms an L at the bottom of pic), for what we think was about 40+ years, so the consistency was something none of us had ever confronted resulting in a very dangerous situation for house and workers. The excavation was along the line where it is in front of the garage, but it started sheering and caving back toward the house and we couldn't backfill fast enough because the excavator was blocked off. I was out there with a shovel in my suit with 3 other guys--gnats on an elephant. Luckily, it just stopped.

 

[mulberryworks]

Ah, the staining. They also have red dirt on Kauai and there's a T-shirt company making that their signature. They wash all their shirts with some red dirt and it stains them red before they do the screen printing.

Yes, expansive soils are a real challenge. On the plus side, I have refined some of the clay I dug up and made some animal figures. I haven't tried firing it yet though so I can't say how good a clay it is.

When I was excavating one hole I found that there was water flowing from under the house into the hole. It had rained two days before and the side and back yards are higher so I suspected that this was underground flow from the high side. I pumped out 150 gallons over two days. Fortunately, the dirt/clay is not very water soluble so it didn't cause a collapse of the sides. I'll have to look at some upslope water flow remediation when this is all done.

 

[JayWltrs]

Perhaps the only thing OK & Kauai have in common!

Wife says I’m OCD re water. Shortly after neighbors moved out, gutters/downspouts mysteriously appeared on their garage. She gave me the look. In my best wild-eyed Daniel Day-Lewis, I roared, “Drainage!” Stealthy contractors are underrated.

 

[bluecoupe30!]

Perhaps the only thing OK & Kauai have in common!

Wife says I’m OCD re water. Shortly after neighbors moved out, gutters/downspouts mysteriously appeared on their garage. She gave me the look. In my best wild-eyed Daniel Day-Lewis, I roared, “Drainage!” Stealthy contractors are underrated.

Drainage? I love improving drainage....now. Cuz I have learned a few things. But after digging a 60 foot French drain myself with only a trenching shovel, well, now I know what a damaged rotator cuff feels like. We seem to enjoy projects where we want to just get the job done the way we want it to be done. I dug because I did not want the expensive contractor to show up with oversize equipment, create too large a ditch, and charge me for way more trucking and rock than would ever be necessary. Got to drive my old '78 F250 around and get just enough rock that was needed, and do it all myself. Definitely a weight reduction summer, but man, that pasture drains well now. Don't get me started on sump pumps!

 

[mulberryworks]

'Water flows downhill." Wise words from my father.
Ignore this fact at your peril.

 

[JayWltrs]

Drainage!

I want that truck! Alas, no room nearby until
kids are in college.

 

[mulberryworks]

Well, it certainly has been a while since I posted about this project but I've got the carport completed. The drainage & landscaping took a while as well and in fact I'm disposing of the last of the dirt from the post holes now. I have some more gray gravel to distribute under a hedgerow and the landscaping will be complete. I do still want to construct the shed at the rear of the driveway so I'll have storage for the parts that come off the E9, but that shouldn't take tooo long. I have pretty much all the materials in waiting. As most are surplus from other neighbor's projects, I have more than I need for the shed and I'll be overjoyed to be able to finally clean house and pitch the unused material at the end.

Here's a photo of the completed carport. I'm pleased that it look pretty much like the renderings I made. It does keep the garage temperature down by shading the glass and aluminum garage door most of the day. It also shades the AC unit for a little bit better efficiency.

The cars are much happier in the shade. Today the high will be 105°F, (40.5°C) and a bit hotter tomorrow.

I'm starting to tidy up the garage again, moving things that have accumulated in the year since this carport project was started. It will be good to be wrenching again.

 

[Markos]

Very cool! Was the post size an aesthetic decision? It doesn’t look like there are any supports under the metal roof, which can’t weigh much at all. Do you have to meet load requirements in TX given that there is no snow to speak of?

I am always moving fill from one portion of my yard to the other. Sometimes I feel like Andy Dufrain trying to figure out where to hide it all.

 

[mulberryworks]

The sizes of each component are determined by the makers, Future Buildings in Canada. The columns are beefy sheet metal and are actually C shaped, open on the back. I initially wanted I beam columns as other carports in the neighborhood were of that design, but finding an engineer to design it and get it built wasn't happening, so this is an existing design, custom fit to my needs. Most of their buildings have an arched roof, and walls, so this was considered a 'special project' for them.

Sure, no no snow load to factor in here, but as I said above, wind is a major consideration. The corrugated roof sections are bolted together by hundreds of bolts and they are quite rigid as an assembly. I've gone out and watched the carport when we had some pretty fierce winds with gusts and it doesn't vibrate, squeak or shift. Each post is held to the concrete column footer with two L bolts, each capable of withstanding a 5500 lb. pull. Each of the four side bolts holding the post to the U shaped bracket that's held by the two big bolts are torqued to 140 ft/lbs. It's not going anywhere unless a tornado comes for a visit.
The maker provided stamped drawings, I had a local engineer draw up the footings according to the loads stated on the drawing and rather than pay the one estimate I got for excavation and footings of $25K, I dug, and poured concrete myself. It took quite a while and they are a tiny bit out of alignment, but there was enough adjustment to compensate, so it's all good.

Corralling the dirt was a major consideration since I was doing most of this myself, by hand and it would take some time. I knew what I wanted, but I didn't know what they were called. Turns out I was looking for some FIBC. Flexible Intermediate Bulk Containers. Or, dirt bags.

You've no doubt seen the large wire boxes with a plastic liner used for storing water or other liquids. Those are IBC, Intermediate Bulk Containers. To get the same sort of function for chemicals, grain, gravel or dirt you need a large flexible bag. They have four bit loops on the corners, so they could be lifted by a forklift and moved around, that I didn't need that.

Once I'd figured out what they were called, it wasn't too hard to find them on the internet. https://www.repurposedmaterialsinc.com/gotSTUFF
I got 5 for $60 shipped which was about right. I filled them with the concrete and dirt from one side, then after about half had gone back in the holes after the concrete pour, the surplus when behind the fence in the back yard for erosion control. Then the bags were filled again with dirt from the other 5 columns.

You can see the wet spot in the first photo where the dirt bag was for a long time. It took a full day to empty and wheelbarrow the dirt away. The bags are rated for 2000lbs. Dirt weighs a bit more than that per cubic yard. They were great because they kept the dirt in a contained space and kept it more or less dry.

 

[autokunst]

I did a brewery and tasting room once, and they had bags like those for the grains. And they used a forklift, too - to bring it up to a big hopper that then conveyored it over to the big stainless steel vats.