Foundations

LIKE the chain that had a weak link, more than one log cabin or summer bungalow has had its life shortened by a poor foundation, or no foundation at all. Builders of log cabins sometimes lay the sill logs directly on the ground. Now it happens that one of the easiest ways to make wood decay is to leave it in contact with the earth. Moisture collecting between the wood and ground, creates conditions ideal for the growth of decay-producing fungi. Hence a log cabin, built flat on the ground, will, in a few years, start to fall apart. The same applies to any other kind of structure. In addition to decay, there are certain in­sects, such as termites, that delight in finding a build­ing with no foundation.

A common form of support for cabins consists of piers made of two or more flat stones laid one on the other. A single stone is not much better than no stone at all, because moisture can still reach the wood and cause decay to set in. When two stones are used, the joint between them stops the rise of moisture and the top stone will remain dry. Do not cement the stones together.

Another support that has been used but is not generally recommended by building experts is a post of cedar or other wood. Some woods, such as cedar, locust, redwood, and pine, have sufficient natural resistance to decay and insect attack to permit their being used without particular protection. Other woods should be creosoted, and it is not a bad idea to use creosote on the woods that are naturally resistant.

The creosote can be applied with a long-handled paint brush bound with wire, or a small, soft-bristled broom, Heat the creosote in a large pail or kettle until it is very hot but not boiling (about 200 degrees Fahrenheit). Do not let it boil over and become ig­nited. An open fire, with the creosote container sup­ported on a grate or hung from a crane, can be used, if reasonable care is exercised. Apply two coats of the preservative, letting the first one dry well before the second is applied. Flow the creosote over the wood, and work it into every crack and hole. After the wood is treated, handle it carefully so as not to break the protective layer. This method of applying creosote can be used for other parts of a building. Coal-tar creosote, a heavy, brownish-black oil, is the type to use.

Posts used as piers should be about a foot in diam­eter, and long enough to extend a yard or so into the ground. At the bottom of the hole dug for such a pier, place a flat stone, to form a footing. This stone should be somewhat larger than the post.

Perhaps the best pier is made of reinforced concrete or of stone-and-cement masonry. The pier should ex­tend below the frost line, or preferably down to solid rock or dense gravel. This is particularly true of a support for a heavy log cabin.

For a concrete pier not resting on rock, first dig a hole about 24 in. square, and deep enough to extend below the frost line. If the house is to rest but a few inches above the ground, build forms of 1-in. lumber

These various illustrations show, first, how not to lay the bottom logs of your cabin, and then the proper methods that will insure long life to a cabin's foundation

that reach to the bottom of the hole and extend for the required distance above the ground. Another way, which saves form lumber, is to extend the boards just far enough below the ground surface to prevent the concrete from escaping beneath them. Use a 1:2:4 mixture of concrete to fill the form. That is, mix 1 part by volume of Portland cement, 2 parts coarse, clean sand, and 4 parts gravel or broken stone. Add water until the concrete will just flow—until it is about the consistency of mush. It is not a bad idea to reinforce the piers by inserting four ¾ in. steel bars, arranging them near the corners and tying them in position with heavy iron wire.

If the pier is to extend for a considerable distance above the ground, as it will on the lower side of a sloping site, the following method of pier construction can be employed: First make a footing by digging a 2-ft. square hole below the frost line and filling it with concrete to within 6 inches of the surface of the ground, using the mixture given. Then, with flat boards, build a form for a post 1 ft. square, extending from the base to the desired height. Brace it with out­side frames every 18 in. Insert four reinforcing rods, placing them 2 in. or so inside the corners, and tying them together at 12-in, intervals with heavy wire or ¼ in. rods. You can fasten these rods to the larger ones with baling wire or similar small wire. Extend cross rods at intervals until their ends touch the form so that the reinforcing network will be held away from the wood. Fill the form with the 1:2:4 concrete mix­ture, tamping it in place with a paddle, and manipu­lating it so that the large pebbles or rock pieces do

Since a cellar is desirable, the illustration at top shows how the foundation wall for a cellar is built. Drawing above shows manner of casting circular piers for use in foundations

not remain near the surface. Let the pier set for several days before starting the cabin structure.

When it is desired to preserve the rustic atmosphere demanded by some types of cabins, particularly log ones, the discordant note introduced by square, plain concrete piers can be eliminated by some form of camouflage. Shrubs can be planted where they will hide the piers from view, or vines can be placed so that they will grow over the concrete. Virginia Creeper (five-leafed ivy) is excellent. For a log house, the piers can be made round, and the concrete painted or otherwise colored to harmonize with the logs. For instance, a chocolate brown, that ought not to produce a discordant note with rustic construction, can be made by mixing burnt umber with the concrete in about the proportion of 4 lbs. of umber to every 100 pounds of cement. The ingenious craftsman can make artificial concrete logs by lining cylindrical forms with rough bark placed with the rough side next to the pier material. Probably the bark will have to be torn from the pier by force, because some parts of it will be imbedded in such a manner that it will not loosen easily. Still another expedient is to apply strips of bark to the exposed surfaces of ordinary piers, fasten­ing the pieces by wires running behind, or by some other feasible means.

If you prefer a stone pier, first make a concrete footing as described or else a loose stone footing. This latter type is made by digging a hole about 2 ft. square to a depth of about 3 ft., and filling it with pieces of stone carefully arranged and compacted so that they will not compress when weight is applied. A loose‑stone footing can be used beneath concrete piers or flat stones.

After the footing is in place, lay up the stones with cement mortar. Whole or split field stones, those gath­ered from beaches, or quarried sandstone can be used. The mortar is made by mixing Portland cement and sand in about the proportion of 1 part cement to 3 or 4 parts sand. The addition of a little lime putty will make the mortar easier to work. A suitable mixture consists of 6 parts cement, 24 parts sand and ½ to 1 part lime putty. Ordinary lime mortar consists of about 1 part lime and 4 parts sand with sufficient water to make a paste. Do not use lime mortar for chimney and fireplace construction. Whatever the mortar you em­ploy, mix the ingredients thoroughly. To do less is a waste of time and material, and a possible source of danger as well. Wet the stones before applying mortar.

Spacing of piers should be in proportion to the load carried. For log cabins, the supports should be placed at every corner and at intervals of 6 ft. or so along the walls. Lower parts of the sill logs are hewn flat at the points where they rest on the piers.

Where a more elaborate cabin is desired, and the added cost is not prohibitive, solid concrete or masonry walls can be used instead of piers. If masonry is used, make sure that the walls are sufficiently massive, that mortar joints between stones do not form continuous lines that might crack open, and that solid stones or bonds extend all the way through the wall at intervals, say one stone for every 8 sq. ft. of wall surface.

Concrete walls for log cabins, according to recom­mendations of the U. S. Department of Agriculture, should be 2 or 3 in. thicker than the width of logs used for the sills and walls, and in no case less than 8 in. thick. Width of the footing or bottom of the foundation will depend to some extent on the nature of the soil, but generally should be 8 in. wider than the wall thickness. If the soil is very soft, a wider footing may be necessary, or piers may be extended down at intervals to bedrock or denser soil or gravel strata. Inspection of other buildings in the vicinity will reveal much about the type of construction de­manded by conditions.

Whatever the type of foundation, it is essential that proper ventilation be provided beneath the floor, to prevent decay of sills, joists, and other wood parts. Some cabin owners block the spaces between piers with masonry, lattice work, shingled panels or other construction, to improve appearance. This is permis­sible provided ventilating openings are left. These can be screened holes about the size of the largest face of a common brick (4 by 8 in.) spaced a few feet apart, the screens serving to exclude insects and small ani­mals. When a cellar is built, the walls can be solid except for the normal window and door openings.

Termites or "white ants" are attacking wood build­ings in many localities. One way of protecting against them is by proper foundation construction and sepa­ration of the wood portion of the building from the foundation by sheet metal. Details of termite pro­tection, as well as protection against other insect pests, are given in a later chapter.

How To Build A Log Cabin