"RoyDMercer" wrote in message ...
"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 agree and second the suggestion to read about retaining walls and
sidewalk jointing as well.

Tom Baker