20 x 30 Single Story in Central NY

[Squirl]

Yes this was my first time with an excavator.  I have worked a few front end loaders, but not backhoe's, at least that I can remember.  The ground was harder to get through than expected.  The machine was pretty easy to work.  They have the joystick like handles and it swings just like a digging arm.  I found it is easier to chop away at the top and work your way down, as opposed to trying to scrape up a vertical side.  When you hit a rock, it is easier for the machine if it is not pulling the 3-4 ft of compacted dirt with it.  Also to break the shale, I pulled the bucket as far out as it would go, and pushed it down against the rock. This would give the full force of the machine and its weight to break the rocks.  Some were so big, I had to dig around.  You can see that in the third trench (the right 30' side).  It was probably 3'x3'x2'.  With delivery, diesel, hours, damage waiver, and cleaning it was around a $50 an hour learning experience.  Well worth it.  I did find that either it is very difficult to keep an exact depth or I lack the skill to do it with this machine.  I will not be using an excavator for my septic.  Because I only have to go down 13" through silty loam for my grey water leach field, I will be renting a trencher.  Because I can put it on a trailer, it is a lot easier on the wallet too.

I went deep, way deep.  Oops.  My plan was actually to go a few extra inches over 48", around 54".  Some areas are 60"-66".  Again my inexperience.  It is hard to shoot the grade too when the batter board strings would be in the way.  I will have to fill it in and compact it.  On the plus side it is very easy to fill it in.  Just walk along the edges and tons of dirt just falls right in.  As you can see, I piled it along the edges.  I left the corners open with the expectation to try and shoot the concrete down them for the footing.

[Windpower]

good job !

[speedfunk]

congrats squirl.  Looks like  great start

[Don_P]

The dirt that came out of the hole is usually not the type that can be put back in and compacted to adequate bearing capacity, generally washed gravel is required.

[Squirl]

Can you expand on that a little don.  I was going to fill a little dirt in to get it level, tamp with a jumping jack, then put down around 6 inches of crushed #2.  I had the feeling that a jumping jack could get the fill and whatever was loose still at the bottom compacted to the same as the soil it is on top of. Along with how crushed gravel can direct a load outward in a pyramid fashion, I thought this would have the bearing capacity for a single story stick frame. I would like to learn more about the soil compaction requirements.

Also if it the dirt is not level and I level it out with crushed stone, say 3" deep one spot and 6" deep another, do I have to worry about it?

[Don_P]

Geotech is way outside my calling. Basically they want you to be on undisturbed soil, signs of filling and tamping have always been grounds for "call an engineer or remove it to virgin soil". Gravel with just a little settling will be better in bearing than the soil in most places, under a footing the depth difference is not a problem. You could also pour it all and just level the top... it's a time/labor/money equation. I'm pouring 6 yards for the footing for the entry stairs tomorrow (architects  , but they will look cool), it got a couple of inches deep in one end but it's cheaper all things considered for me to just pour a little more.

[Squirl]

Yeah, I saw that clause for footings in the code and it worried me a little.  I could never get the ground that level.   I worked on an excavation crew for a little while and never saw almost any foundation go in without some tamped crushed gravel underneath.  I rarely see it on here either.  I was not worried about the stone, because that is even considered a footing in and of itself under the code.  I also called both the excavator that I am friends with and the building inspector and ran my plan by them.  They both said it was fine.  I did not get into specifics about the soil, I just said "level and tamp".  The inspector is going to drop by this week and check the hole.  I will check to see how much I have to come up.  I have 12 yards of stone and I am only using around 1-2 yards in the greywater leach field. Even if I have to come up 12" on a 24" wide 100 ft long hole, it would be 7.5 yards of stone. Thanks for the insight.

[diyfrank]

Squirl, good for you for doing your own excavation.
I know I've done over 1000 residential excavations in resent years and I can tell you your not the only one that over digs their grade. I would agree with your friend and the inspector that leveling and tamping will most likely be fine.  What you should do anytime your soil is in question or even anytime period is probe it. Any reputable excavator dose and is usually the first and only thing a geotech will do if asked to check your sub grade.    Take a piece of 1/2 rod 3' or so long and weld a short piece to the top as a handle to form a tee shape.
check your grade by placing your body weight on the tee handle. The probe should not penetrate more then 1 or 2 inch's. If it penetrates lets say 6" a geotech would suggest compacting and then re-probe or take out the 6" of loose soil. Your not on bearing soil till you reach that point whether its 2" or 10'. Some soils will never pass a probe  like clean sand but thats will be obvious. I've mentioned the importance of probing your soil in other threads and I'm sure I will again. My opinion is if it doesn't pass don't build on it.

[Danfish]

Here's what the probing looks like.  This is the soils engineer checking in footing area where there was suspected old fill.  After his investigation, he recommended we run wacker over area...came out hard as rock.



Because we uncovered an old burn pit in footing and slab areas, removed considerable quantity of contaiminated soil.  Used 3/4 inch crushed rock to backfill...much easier to meet necessary compaction. I have used rock backfill on a number of projects with excellent results.

[paul s]

Where exactly are u building in certral NY.  I am origionally from Onondaga County?

[John Raabe]

I remember once asking my engineer how long it takes for fill to settle to the point that you can call it "undisturbed".

He said you only have to wait until you run a glacier run over it. That'll tamp it down pretty good!

[duncanshannon]

"It took half a day to find square again."

yikes!  you are a patient man!

what do you do for your day job?  You mentioned they wouldn't rent a big excavator to a non-contractor.

[Squirl]

Typing  from a phone at the site. Thanks for the tips everyone.  I got here Friday after a week of rain.

Clay + water= pond


water + filled clay = MUD


I spent most of saturday scraping it down to virgin soil.  It was easy to find, it was where the mud ended.



Filled with a 3-6 inch gravel base to get it level.








Tamped with a jumping jack.



It's been raining for two days while I built the forms and it is holding firm. Pictures to follow next week.  It is in Otsego county.

Edited with pictures.

[Squirl]

Footings are in. More pictures later.

[Alan Gage]

You're not wasting much time. I can't remember, did you decide to do block or poured?

Alan

[nysono]

Ahhhhh getting footers in the excitement level is really going up now.  Actually getting something permanent in the ground helped my anxiety level and it has gone fairly fast since then.  Good luck!!

[h0rizon]

Your making great progress!! 

[Squirl]

So in the rain I scrambled to cut the rebar and install the forms before the building inspector arrived.  I expected to be done by that day, but I had to spend a day shoveling out all the mud from the fill dirt I put it the hole.  I don't have many pictures because I was really scrambling.



It was good enough to pass inspection, but the inspector said, if it blows out it is my problem and that I should brace it more.



6 pallets of blocks and 65 bags of mortar showed up too.



The next day I was going to level the forms and pour concrete, when I woke up to this.



It was like building sand castles in the surf.  I called and canceled the concrete.  By midday the hole was empty again with a bilge pump.  The deeper areas of rock tamped down an extra inch lower than the other side so the forms had to raised and braced.  I ordered 3 yards of concrete to make up for the low spots and spillage.



I called back and they said they probably would be able to pour the next day and it was supposed to rain the day after that.  So I asked if I could still get it that day.  They said at 2:30.  It was 12:30.  The fact that the mix was almost solid with no slump, they didn't charge me for the "empty" concrete fee and that the time was required to be 2:30 and not 3:00, I surmise it was left over concrete from another job.  Oh well it got done.  That is not an optical allusion. The forms bowed in certain areas and ended up being 16" wide in some spots.  I used almost all 3 yards according to the driver.  He was able to put the shoot in the center of each wall and reverse as he poured.  He only missed the forms a few times.  It sure tore up the site.


After spending hours setting up the batter boards AGAIN, to find the exact corners to set the blocks to stay square.  I fell off the ladder when using the plumb bob.  I landed with my spine on a large rock/clay ball that came off the side wall during the pour.  I can barely move and can't lay block the two non raining days of the week.

[Squirl]

Thanks for all the positive comments.  It is square within 1/2 inch.  I was told that was pretty good for a footing.

I originally had decided on a concrete wall, but when no one would rent forms in the area and because my crawl space had almost no unbalanced fill, a dry stack wall was a faster and less expensive option.  After the excavator barely got through the rock and clay, I could only get one trench wide within the weekend I had it rented for.  I would have needed at least 48" to get enough room to stack the block and surface bond cement both sides of the wall. That would have required and extra weekend of work and another $600. So now it is going to be mortared block.

Duncan, I am an white collar office worker.  It was immediately apparent to the people when I called to rent the excavator.  "You don't do this for a living do you?"  Was usually one of the first questions they asked.  It must have been pretty obvious.

NYsono, yeah the concrete pour was the most anxiety of the build.  Everything else can be easily fixed with some time and money.  Everything had to be just right for the footing or everything for the house would be off.  I just have to get the wall mortared before the freezing temps now.  Not as stressfull.

[nysono]

[quo
NYsono, yeah the concrete pour was the most anxiety of the build.  Everything else can be easily fixed with some time and money.  Everything had to be just right for the footing or everything for the house would be off.  I just have to get the wall mortared before the freezing temps now.  Not as stressfull.

[/quote]

Are you planning on leaving blocks uncovered over the winter or building up this year?  If so be very careful....I was sternly cautioned against this last year (thought Id get a jump on this year if I git that done last fall)


Hope your back recovers quick....I know they can be debilitating from first hand experience.
Steve

[Sassy]

Sorry to hear of your fall, Squirl    Hopefully its just some bruises.  Part of my back problems are from all the falls I took when we were 1st building our underground cabin.  Wasn't used to the fine clay w/lots of rocks that would slide right out from under your foot & send you flying down the hillside or doing the splits, landed on my tailbone several times.  Now I watch the ground all the time.

Making good progress in spite of the weather not cooperating. 

[Squirl]

Rather than stare at a project I couldn't work on or push myself into a serious injury.  I went home. This is how I left it:




NYSono.  I plan on getting all the block work and back filling done before the frost.  What were you warned of?

[Alan Gage]

Good luck with the block and don't rush that first course. I only had 2 courses of 6" to run on mine but I hired it out to a block layer. He's a meticulous guy and he and a helper spent about a day and a half squaring and setting that first course of block (about 100 blocks). After they got the 1st one perfect the second course almost went up by itself.

Alan

[nysono]

Rather than stare at a project I couldn't work on or push myself into a serious injury.  I went home. This is how I left it:




NYSono.  I plan on getting all the block work and back filling done before the frost.  What were you warned of?

If you are going to be capped I think you are ok.  Biggest thing is water getting into blocks and freezing.  If you are backfilling Im assuming you will be capped and all blocks sealed to grade, then not a problem.

[Squirl]

Yeah, I have another month and a half of weekends before frost sets in.  It will be covered by a tarp after that.