Thinking about building a Log Cabin? This is how your determine
your foundation
There are at least three types of foundation that may be used
with many of the popular cottage plans available today. These
are: a concrete slab on grade; a full foundation wall (or
basement) around the outside perimeter of the building; and a
pier type of foundation. Most plan drawings show pier
foundations, because they are usually the cheapest to build and
the easiest for the amateur craftsman to construct.
If you have a level piece of property on which to build, you may
want to use a concrete slab. It is fairly simple to make. After
you have selected the cottage or camp you wish to build, refer
to the foundation plan that is shown with it. Get the over-all
dimensions firmly in mind.
On your site clear away the brush and lay out the lines of the
building with strings and batter boards. The next step is to dig
a trench about 12 inches deep and 12 inches wide around the
perimeter of the building. If you hit some large rode, leave it.
Taper the inside edge of the trench as shown. By cutting the
outside edge of the trench square, you can use it as part of the
form for the beam edge of your slab.
While you're trying to get the crimp out of your back, have
someone call the local supply yard and have them send you enough
gravel or crushed rock to lay a 6-inch bed under the slab. The
following table tells you how to figure how much grave! or
crushed rock you will need.
At this point, while you are waiting for the delivery of the
material, you will want to get all the rough plumbing in place.
This means that all the pipes which will be permanently buried
in the slab should be put in place, connected, and tested.
When the rock or gravel has been delivered, borrow the
neighbors' wheelbarrow and start spreading it. The finished bed,
in cross section, will look like the picture at the side. Don't
stop now, you've only begun. Get enough 15-pound roofing felt to
cover the slab area. Cover the gravel area with this, lapping
the edges about 3 inches. You're doing this, I might add, to
keep the ground dampness from coming up into your finished slab.
Around the outer edges of your cottage build a form as shown in
the picture at the side. I assume that you didn't knock the
walls of your trench in; if you did, be sure to clean them out
again. You are now ready to lay the reinforcing down. The usual
procedure is to use wire mesh weighing 40 pounds per 100 square
feet.
If you can't get it, the best substitute that I have seen is
heavy turkey wire (welded type). Roll out the mesh. Put some
small rocks under it so that when the concrete is poured, the
mesh will be in the slab. Along the bottom of the trench use two
%-inch reinforcing bars. You're actually building a concrete
beam around the perimeter of the building.
You are now ready for the big pour. By this time you will
probably be willing to call for transit mix. When you ask for
this prepared mix, tell them you want the kind that reaches a
minimum compressive strength of 2,000 pounds per square inch in
28 days. If you are going to mix your own concrete, use I part
portland cement, 2 parts sand, 4 parts coarse aggregate, and
enough water to make it sloppy.
The actual water content should not exceed 7|/2 gallons per bag
of cement. The table will help you to figure how much you will
need. The thickness of the concrete slab should be a minimum of
3 inches. After you have the framing up, you will want to add
one more inch of smooth concrete for your final finish (I part
cement, 3 parts sand).
You can also add color to this batch if you don't like the
natural gray of the concrete. There you are. Except that you
should also put some 6-inch stove bolts along the outer edge of
the slab, about 8 feet on center, starting roughly I foot from
the corner, to fasten your sill. If you are going to use the
cottage year-round and are building in the northern states,
insulate the outside perimeter with Fiberglas boards.
If you use the slab described, be sure that the soil is porous.
Heavy clay or stiff soil will require the building of foundation
walls to the frost line to prevent heaving.
About the Author
About the Author: Jack Hudson is a writer for
http://www.log-cabin-plans-n-kits.com and
http://www.best-house-n-home-plans.com/. These two sites work
collectively as a resouce for the planning and building of log
cabins as well as choosing from different house plans. Visit one
of these sites for informative articles as well as free TIPS for
building a log home or choosing a house plan.