Ground work help

[CanuckGT]

So I plan on putting up a fair size shop here in the spring and would like to cut costs as much as possible.

So I plan on preparing the ground myself and maybe even forming/rebar as well.

So where I plan on building is grass right now and fairly level ,maybe 6 inch drop on a 40ft run. I assume I need to scrape off the top soil until solid ground,as well as level it. I do own a 30hp tractor with blade and bucket but can hire a grader for cheap to peel off the soil.

So once the top soil is off and dimentions are established I will need a footing of some kind (normal slab garage build) so need a deeper perimeter for wall
support, hoping my tractor can do this..

so , am I on the right track here??, as you can tell, never built more than a garden shed so any and all help would be appreciated.

 

[Milton Shaw]

What is your location, it makes a difference in foundations for frost heave. Also are you in heavy snow regions. A lots of people here will help but give locations to give us a start

 

[Krash Kadillak]

I've got a sneaking suspicion he's in Canada..........

 

[CanuckGT]

Located in Alberta, Canada so temps of -40 to +40c!!

 

[CanuckGT]

So...nobodys ever done their own prep work??

- looking for, how much soil to remove?
- preparing the footing?
- type of file?
- tamping?
-rebar grid?

 

[jlckmj]

I just had the pad for a 24X36 poured.

I removed the soft black top soil with a bobcat. I had to go down about 20 inches on average, I went down to the point that the dirt started to be mixed with clay. You can tell as the soil will take on a different color and texture. I also went about 3 foot wider and longer so there was plenty of room for error.

At that point I had 8 quad axle trucks deliver loads of sand and fine aggregate mix to fill it back up to the height I wanted, I would spread the new out evenly and each load would ad about 4-5 inches.

When the quad axle came back I had him drive back and forth over the previous load of aggregate and compact it with it's new load of about 70,000 lbs. I was lucky, it was an open area and he had no problem doing that. (it sure saved time with the compactor)

Around here we do monolithic slabs with the pad and footing all one pour tied together with rebar. Once I had the pad built up to the height I wanted, the concrete guys came in and dug down the outside perimeter for the footing with the rebar.

I think you will have a hard time doing it with a farm type tractor if you have to go down any depth, but it can be done.

Good luck, Jim

 

[bczygan]

It all depends on your subsurface geology. What is the thickness of the organic material? It must all be removed. I had a bank branch I built on a farmers field. The topsoil was 6' thick and had to be removed and replaced with base material placed and compacted in 8" lifts.
What is the sub-grade material?
How does surface and subsurface water move on the site?

 

[R6 Racer]

Subscribed!

I am also looking to the same thing here but mine will be quite a bit smaller 12 x 15 (shed/work area). My property is sand on clay. The sand varies from 12 to 18 feet deep, then its all sand, desert sand, so dry it blows away with the wind once the 18 or so inches of top soil is removed. (Great drainage!)
I am hoping to tag along with this thread & get answers for my geologic type. I hope this is not considered hijacking. I figured since my question is the same it would be ok. If not, someone slap me & I'll start my own thread.

CanuckGT where are you located? Anyware close? Southern Ontario here. It would make things even easier if both our properties had the same geologic makeup.

Steve

 

[Gary S]

I did my garage in 2004. I didn't have a tractor, so I rented a Bobcat for half a day. The Bobcat made easy work of leveling the ground. I had about a 2 foot drop in the ground from one side of the garage to the other, so I had to did a deep trench on the uphill side and put in a retaining wall. Yours sounds like your on much more level ground so it would be simpler.

 

[nehog]

I did my shop's site prep with a Ford tractor with a front end loader... Didn't bother with a blade at all, just scooped, carried and dumped. Had a huge pile of loam when done (which went to good use to fix some other spots in the yard).

 

[CanuckGT]

Im near Calgary,alberta.

Thanks for the replies, not really sure of the soil in the area planned, most is heavy clay I believe,guess will find out once I start digging!

I may have access to a bobcat which would help big time!

Once down to clay could one make a deeper trench around the perimeter as wide as the bobcat and use this as the deeper footing area? frame it up ,pour ,then back fill ? Or does one frame up the forms then dig down some as well as wider for the footing area?

 

[joshuaz223]

it depends on what is common and required in your area. if you have a lot of clay i would dig down to that and then place a bed of gravel for drainage and tamp that down. as far as what to pour you can do a tapered slab where it is thicker around the edges 6-8" then tapers to 4" in the center. if the bldg is going to be real heavy you can do a footed pad where you dig a 10-16" wide footer around the perimeter about a foot deeper than the pad then pour that all at once with the slab. i wouldn't recommend that in your area due to the freeze issues. i would do the tapered slab with welded wire in it for reenforcement. make sure the top of the slab is a few inches above grade. nothing is crappier than water running into your garage every time it rains.

i have poured a bunch of slabs and will never do another. do all the prep work and let a pro break his back doing the concrete. rent a tamper and have a good time.

 

[ddawg16]

I live in Sunny California...not frost....but expansive soil and earthquakes....I had to dig down over 2' for the footing....in cold climates you want to go further....

Click on the Garage Build link in my sig for pics of my foundation....

While doing it yourself is very doable.....I think your under estimating how it should be built....

Remember...once the concrete is poured....'fixing' issues is not so easy...

 

[nkachur]

I live near Winnipeg and my build (see link in signature bock) goes thru my sight prep up to now where I am close to framing inspection take a look and feel free to ask questions.

 

[Gary S]

I live in Sunny California...not frost....but expansive soil and earthquakes....I had to dig down over 2' for the footing....in cold climates you want to go further.....

Actually, you are worse off in Sunny California than we are in cold climates. Your earth quakes cause many stability problems we don't deal with in the cold.

My frost line is down to 6 feet on a cold winter, but my garage footings are only about 1 foot down and there are no problems with that. The people who think cold weather causes problems must all live in warm climates and don't have any true experience with the cold. Around here it is standard practice to pour a floating slab with thickened edges for a garage. Buildings set up that way last longer than the people who built them.
Temperatures here vary from -45 in winter to +110 in summer.

 

[CanuckGT]

Nkachur, it looks like you scraped away the top soil, then built up your base leaving the wider,deeper footing area,is this correct? Or did you scrape away the top soil as well as dig deeper around the perimeter for your footing area, then put in your crush?

Thanks for the link,looks good!

 

[DekeT]

Hire the grader for cheap. Much better things to with a 30hp tractor than trying to remove topsoil or cut grade for a foundation and slab.

 

[nkachur]

Nkachur, it looks like you scraped away the top soil, then built up your base leaving the wider,deeper footing area,is this correct? Or did you scrape away the top soil as well as dig deeper around the perimeter for your footing area, then put in your crush?

Thanks for the link,looks good!

My slab is made of a thickened edge, 16" x 16" tapered into a 6" slab the engineer required 6" of granualar fill (gravel) below the entire pad and 1.5" foam under the 6" concrete portions and plastic under the works.

I was told to scrape off all organic material (top soil). The site was sloped slightly down to the back of the building (almost 2" over the buildings 40' length) and I had to build to a slab height specified by the RM (based on property drainage and high ground).

The back was dug down only about 6" to clear the top soil and the front was dug down almost 2 feet. I had the whole area pretty well level and then built up the areas where the concrete was thicker using crushed limestone 4" down followed by 3/4 " down.

The sub soil here is vey sandy with a little bit of clay so the drainage is really good.

I have a very large quarry operation about 10 miles south and the limestone is readily available. So depending on the price of gravel in your area this might not be the best approach. For me it worked well and minimized the requirement for a back hoe/excavator. This is a bit long winded so if you want a summary I did answer 1.

it looks like you scraped away the top soil, then built up your base leaving the wider,deeper footing area!

I am glad that you found my thread useful. Please let me know if you have any more questions. Best of luck on getting you build started.