"James Nipper" wrote in message
...


I want to build a small garage at a vacation cabin in the mountains.
Several years ago, I had a spot cleared at a spot that I intended as a
level
parking spot. I had some rock delivered, so that the spot was level.
So,
I have an area of about 25 feet by 35 feet, where the rock (because of
the land slope) is about 1 foot deep on one end, and about 6 feet deep on
the other end. (That is quite a pile of rock, and has been a good
parking
spot).

Here is my question: I know that foundation footers should be dug to
below
the frost line, which in this area is about 3 feet. This is because of
frost heave, as I understand it. But, it is very unlikely to me that I
would
experience frost-heave in an area where I have 3 to 6 feet of rock, right
??

I can't remember the type of rock, but I think it is limestone. It is 2-3
inch size. It has some "fines" in it, so that is has bonded together very
well. It is VERY hard , and stable.

Questions:

1. What type of footer would I need, and how deep should I did it ?

2. I am assuming that I would have a footing around the perimeter of the
garage, and then the concrete floor of the garage would just be poured 4-5
inches thick, right? Is that what is called a monolithic slab? Would I
still need some pea gravel and/or sand, to be put over the rock described,
before the concrete is poured ?

-------------------------------

I know these questions are basic, but I don't want to sound too green to
my
contractor.

Thanks for any advice !!

--james--


A monolithic slab is a one-piece unit. It consists of beams on the
perimeter, and a much shallower surface within the beam perimeter. How much
stone, road base, or other fill depends on what you intend the slab to
support. Yours will probably require at least one beam down the center as
well. You will need steel (1/2" rebar) in the beams and to support the
surface of the slab.

The garage wall bottom plate should be secured with 1/2" J-bolts embedded in
the slab's perimeter. Where exactly these should NOT be depends where you
intend to put the garage door and any other entry door. So you need to come
up with floor plan now.