Owner-Built Home & Homestead
(Page 3 of 15)
Where basements are included in the building design, all sorts of complex foundation problems arise. High water table, moisture from rain and snow, and underground springs all contribute to the nuisance value of basements in general. Basically the problem is that water seeks its own level, and one must either drain it off (seldom possible on the average basement site) or build a swimming pool in reverse.
RELATED CONTENT
The additional cost of a basement in a one-story house of average size is $1200 or more, depending upon excavation expenses. At least 10% more living space above grade can be had for the same money. Basementless houses appeal to our younger, low-cost oriented generation because of the smaller initial investment required. Older people, for whom stair climbing requires extra effort and hazard, also react favorably to homes without basements.
Soil conditions, frost line and ground water are the main factors which influence footing design, but, in addition, the site contour and the distribution of building weight must be considered. To assist the ownerbuilder in his choice of foundation, various types of footing are outlined below.
A stone-filled foundation trench, extending below the frost line, was suggested by Frank Lloyd Wright in his book The Natural House. Actually, this method was used a century ago by masonry wall builders in the northeast. Stone ballast (as previously mentioned, similar to that used on railroad beds) has also been successfully used for masonry wall support in areas of deep frost penetration. It will support exceptionally high bearing weight and at the same time give sufficient drainage to prevent frost heaving.
Another variation of the stone ballast idea comes from Carl Boester, Lafayette, Ind. Boester developed a mortarless concrete block foundation system, supported on a gavel fill. Steel rods and metal corner anchors permit an entirely dry assembly, built without water, concrete, mortar, or the need of electric power. Half-inch steel pipes are simply placed through the center core of standard concrete blocks and tightened at each corner (post tensioned) and, in addition, one-fourth inch steel cable made taut at corner diagonals.
For those who may consider Boester's foundation system a bit too "fussy" and involved, I can recommend from experience an alternate method; the concrete block and mortar method. Trough or lintel bond blocks are laid directly on a concrete footing. With a mat-type footing, where the floor is reinforced by wire mesh to act as a unit in distributing building loads over the entire surface, the inside wall of the lintel block is broken out to receive a continuous pour of concrete. Thus the block doubles as screed runner and form for the poured floor and the mat acts as both foundation and footing. Mat footings are generally used in areas where there is little to no freezing; in other areas, mat footings can be designed to bear directly on concrete piers sunk below the frost line.
Page:
<< Previous 1 |
2 | 3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
Next >>
