"RoyDMercer" wrote in
:

"news.individual.net" wrote in message
...

I have some questions about under what circumstances footings are
needed, and when needed, under what circumstances they must be
below frost level.

I live in a mountain area when on occasion, the ground freezes to
several feet of depth.

Here is my perception of "the rule" :



"For load-bearing structures, footings must be dug, and in areas
where frost-heave is a problem, those footings must be below
frost level."



Perhaps this is a correct statement, or perhaps it isn't quite
complete, I am not sure. I suppose the main problem that I am
having is determining
what
is a "load-bearing structure." I think some of the fine expertise
that we have in this esteemed group can get me straight on this.

I have several small projects in mind. They are listed below, and
I am wondering if in any (or all) of the instances, I would need
footings and
if
so, would they need to be dug below frost line?

1. Small rock wall flower bed-- I plan to build a very small
circle around
a
flower bed about 5 feet across. I will be using river rock, with
an
average
size of 4 X 6 inches. The little wall or rock border will be
about 12
inches
high, and about 5-6 inches thick. I would not think the weight
would be
more
than 50 lbs per foot of wall area.

2. Concrete pathway-- I plan to build some concrete pathways,
about 3 feet wide and I suppose about 4-5 inches thick. It would
seem that I could peg some forms to the ground, and pour the
walkway with concrete. It would not appear to me that this would
be a "load-bearing structure", but I am very inexperienced in
these areas.

3. Retaining wall for flower bed. This is an area in a limited
area of a flower bed adjacent to my house, where I need to
replace a small area of a retaining wall, which will be built a
sloping area. The entire wall will
be
about 8 feet in length, and (on the sloping ground) will be about
4 feet high on one end, and will slope to about 1 foot in height
off the ground
at
the other end of the 8 feet. This wall will be built of 4 X 4
pressure treated beams, of .8 retention. There is a bit of "load"
here, as the timbers themselves are pretty heavy. At the "high"
end of the wall, I
would
have about 8 or 9 beams, but because of the slope, most of the
beams will
be
less than 8 feet in length (wish I could draw a diagram).

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

That's it on the projects. I have a number of questions:

1. Would any of these projects require footings ?

Your rock wall may need a footing if it will be held together with
mortar. Loose stones stacked on top of each other don't
necessarily need a footing because since the rocks will be able to
move independantly of each other.

Concrete pathways do not need footings.

Retaining walls made out of 4X4s don't need footings because each
beam will move independently of each other. You really should do
some research before building a retaining wall that size because
there are a few things you'll need to know about them. Improper
drainage at the top of a retaining wall will cause it to fail.
Improperly anchored retaining walls will fail also.


2. If any require footings, would they have to be below frost
line?

Footings are always to bedrock or below the frost line (unless it
is impractical to go below the frost line).

3. Is rebar required in any of these projects?

It is not required, but steel reinforcement greatly improves the
strength of concrete. Sometimes they use a steel mesh under
sidewalks and driveways, but rebar is better. If you've ever
tried to bust up steel reinforced concrete and non-reinforced
concrete, you'd be able to tell a big difference.


4. Can the walkway be poured right on the ground, or should I
start with a 3-4 inch bed of gravel ?

It is a good idea to put a layer of gravel, followed by a layer of
sand, then your concrete. This will keep water away from the
concrete. Many contractors just pour the concrete right on top of
dirt. This is OK, but it's very likely you'll have spots that
will crack and bust apart from frost heave. You also need
expansion joints at regular intervals. The more problems you'll
have with frost heave, the more expansion joints will be needed.

5. Does gravel itself help with the frost-heave problem ?

Yes. The gravel keeps water from directly underneath the
concrete.




I would consider using concrete with embedded fiberglass fivers rather
than rebar. In our area (Southwest Ohio) hardly any rebar
reinforcements are used. If you order concrete, rather than mix it
yourself, you can get eh fiberglass already mixed in. Consider it.