Frost heaving

[firefox]

I just finished talking to the Backhoe guy and he said that the property I have
may be a little difficult to dig because he thinks it may be very hard. I suspect that
a lot of it is white rock which is common in that part of Nevada. also refered to as
Diatomaceous earth.

He also said that it is a good idea to dig 3 foot foudations in case I ever wanted to sell the place because of the way banks do loans etc. I trust this guy in that he is
only telling me what he thinks to be good advice and I know he isn't trying to shake me down for more money. As it is his prices are very low.

My question is, if the ground is very hard, wouldn't this rule out any frost heaval ?
Also. since white rock is a good insulating material, assuming it is reasonably pure
wouldn't this also tend to eliminate frost heaval?

I am thinking that a strategy might be to have an insulated border around the perimiter which I have heard protects you from the frost heaving. The foundation
is likely to be slab on grade with imbedded pex tubing for heating, and the slab will
be on top of insulation to take care of any irregularities of the insulating value of the white rock.

Can I make a case for not needing 3 foot foundations in the event I ever wanted to sell. Barring a disaster I don't expect to ever move again. but you never know.

Bruce 

[glenn kangiser]

I used to hit layers of DE when drilling water wells.  It was very hard to get through - I haven't seen it in rock form - just pulverized from drilling through it and in swimming pool filters.  Diatomaceous Earth  is made of  tiny sea creature shells (as I recall from memory -hope I got it right ) that look like snow flakes under the microscope.  Great filter media.  Some how it really locks together tight in rock form.

Seems it should be pretty stable - the local guy should know.

[firefox]

Thanks Glenn,
   I don't think he questions that it is hard enough for a good foundation. I think that what he is saying is that the banks attitude will be that if it doesn't have a 3 foot standard foundation that it will be subject to frost heaving.
   What I am trying to determine is that if I use the perimeter insulation method of protecting against frost upheaval, is this something
that the banks will sign off on, or is it too advanced a topic for them? Also is this method reliable or am I deluding myself again?

Yes you have the right idea about this stuff. It is not actually rock, just nick named that because it is so hard. I want to make the best of this stuff. I figure that if it is as good an insulator as they say it is, I should be in a good spot to do a radiant heat slab.

If it is as pervasive as I think it is on my property, I am also considering cutting in a basement into a hill. What kind of tools would be the best to do this with? I was thinking that drilling a sequence of small diameter holes first both vertical and horizontal if it is easy to drill into, and then hammer some kind of wedge type tool in to do the cut. I am just guessing  at possibilities since I really don't have a clue.

Thanks for any tips.
Bruce

[John Raabe]

Bruce:

See this free download document at the main countryplans site: http://www.countryplans.com/Downloads/shallowfound.pdf

Your project seems like an ideal application of this flared insulation strategy. The technique is well proven in much more sever climates than you will find in Nevada. It is not, however, well known in much the US and you would be wise to print out the document and save it in your house file to show any questioning future buyer.

[firefox]

Thanks John,
   That is exactly what I have been looking for. I suspect that the white rock is probably more insulation than I need, assuming that it is uniform, but I will add additional insulation to be on the safe side and bring it toward the goal of having a super insulated house.

Depending on difficulty, I may even bury a water tank under the foundation to act as a radiant heat resevoir assuming that the white rock is as prevalent as I think it is.
Bruce

[glenn kangiser]

I think the tool for the job would be a Bobcat or Backhoe and Hydraulic Jackhammer.  I am taking out solid andesite , diorite and porphyry with it.  Slow but No problem.   

I use the jackhammer to break it down about 20 inches then the bucket to remove it doing the whole area each time before switching tools.

[firefox]

Thanks Glenn,
   That is exactly what I needed to know. Now all I have to do is find a backhoe I can afford to buy.
I might try to rent the one from the local guy, but I think he keeps it pretty active himself.
Bruce

[glenn kangiser]

You can get a Bobcat with a backhoe attachment and a toothed digging bucket and a jackhammer for it.

Check this out.

[firefox]

Can you get me a used one in running condition for under 7k?
I would then have to get it to Eureka Nevada from Berkeley.
I can borrow a trailer, but I don't exactly get good mileage on my M54A2
5 ton.  So I guess I am just dreaming here, but I sure would like to do this myself.
Thanks Glenn!

[firefox]

I'm  a little slow Glenn...I finally realized that the link was a video 

How do you think that rock would compare with the "white Rock"? Harder or softer?

Would the BobCat fit on a 7 1/2' x 14' cargo bed, and if not, how much over is it?

Is there a cure for this disease?

Thanks,
Bruce

[glenn kangiser]

I found a broke Bobat for a friend for 5K and he did probably 5K repairs on it.  Key to being successful with this old machinery is to get the books and do the work on them yourself.  Otherwise the shops will kill you.

Generally a decent used Bobcat is around 15k - you would likely want at least an 800 series in the older stuff.

The diatomite shows to be a 1 to 1.5 in the scales being silica shells of the diatoms, and the greenstone is very hard - maybe a 7 ot 8 , but the brown rock in video I would say is a 2 to 3 or so.

The thing about the diatoms is that they seem to be rather toughly interlocked together making them harder for well drilling than they should seem to be -- I haven't worked with the rock on ground level.

The Bobcat probably takes around 10 or so feet - smaller ones weigh 5 or 6 thousand lbs and mine weighs 12 thousand with the tracks on it - It's a 963 so pretty large.  800 series  or similar should be fine.

No cure Bruce-- the one who dies with the most toys wins.

[firefox]

Thanks Glenn,
  You really came through. I just hope you don't get into trouble for
turning me into an addict...
Bruce

[glenn kangiser]

I'm tough, Bruce.  I can handle it.

[jr1318]

Firfox,

Shallow frost protect footing is the way I built. I had absolutely no problems with the inspector and I am building in northern Wisconsin. I have been in the same area since iI was a kid at my parents cabin that was strictly slab on grade, which is no longer allowed. One thing you dont want to forget is to use the high density foam for this. My cabin has been in the process of being built for two years now and show no signs of heaving. I hope you feel more comfortable with this method now that you have talked about it with someone who has used it.

Jim

[firefox]

Thanks Jim,
  If I could just keep from reflexively hitting the tab key
Yes that does bolster my confidence alot to actually know someone who has had sucess with this method.
and like Glenn says
Bruce

[glenn kangiser]

How is the slab on grade doing, Jim - and

[jr1318]

Going great Glen 2 years now and all doors and windows operate fine, have saw no signs of heaving. The cost to build this way was very cost effective, 300.00 for excavating and 2700 in materials, I framed forms but had someone else pour, with his discount on concrete I couldn't pour it myself for the price.

[glenn kangiser]

Good to know.  It is very common here in California with no frost problems.  The floor of choice for our crackerboxes by the thousand.  Thanks.