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Mortarless Masonry: The Natural Alternative To Concrete and Tar
Stone is one of nature's finest building materials. It is plentiful, free, attractive, and enduring. Long before mortar was developed, stone was used to build walls, walks, roads, towers, and monuments. Some of these structures, like Stonehenge in England or the great monolithic statues of Easter Island, have withstood the ravages of time for millennia. In America mortar-less stone construction is chiefly associated with New England. There, colonial farmers made a virtue of necessity by using stones from their rocky fields for everything from walls to root cellars.
The principles of mortarless, or dry wall, construction have remained unchanged over the centuries: walls must be perfectly vertical, their individual stones should overlap each other, and the base of the wall should be as wide or wider than the top. Materials have remained largely unchanged, too, although brick has been added to the dry mason's repertoire and is especially useful for walkways, driveways, and patios.
Almost any size, shape, or variety of rock can be used for dry wall construction. Old foundations, loose rubble from an abandoned quarry, a rock-strewn field, or the bed of a stream are likely sources of building stones. If it is not your property, be sure to get the owner's permission before removing any rock. And never attempt to quarry rock without professional help; rock is massive (170 pounds per cubic foot for granite) and can break unexpectedly.
Tools and Supplies
The tools and equipment needed for dry wall stonemasonry tend to be simple and rugged. Most, if not all of them, will already be part of your home stock of tools; others can be purchased as the need arises: there is little point in investing in special chisels and a set of steel wedges, for example, if you are not going to split stone. Whatever tools you buy, be certain their quality is high.
Rocks can be enormously heavy, and sudden, unexpected failure of a piece of equipment can cause serious injury.
You should also be sure to purchase and use the three items most connected with safety: heavy-duty steel-toed work shoes, a pair of sturdy leather work gloves, and safety goggles with plastic lenses to wear whenever you chip, shape, or otherwise dress stone.
Moving and Lifting Large Stones
Shaping, or dressing, stone can be tough, exhausting work and should be avoided if possible. Moreover, the rough, natural surface of a rock will add much to a wall's character and beauty. Occasionally, however, a bit of dressing is essential. Use a chisel to chip off an unwanted.
Attention to the Basics Gives Lasting Results
There are three types of dry walls: freestanding, breast, and retaining. Breast walls are simply rock pavements laid into sloping ground to prevent soil erosion. Retaining walls are similar to freestanding walls except that they require dug-in foundations and are open on only one side-the other side butts against an earth terrace. Both retaining walls and dry walls are held together by friction protuberance on a flat side, a mason's hammer to dull a jagged edge, or a bush hammer to powder a point. Brute force blows with a sledgehammer can pulverize a lump or even an edge, but they may also split the rock. If a rock is too large to handle, it can be split. Whenever you split or shape rock, be sure to wear your goggles--a flying stone chip can blind you.
and gravity. Friction is maximized by laying each stone so that it makes the greatest possible surface contact with the greatest number of stones around it. Since gravity works in only one direction-straight down-the wall must be perfectly vertical. If it is, the overlapping weights of the individual stones will effectively knit the structure together along its base line. I f the wall is out of plumb and leans, it eventually will be reduced to a pile of rubble. When constructing either a freestanding or retaining wall, set up stakes and stretch a line between them at the planned wall height. Along with a carpenter's level, the string and stakes will act as guides to keep the wall even and vertical.
Principles of a Freestanding Dry Wall
Cap the wall with heavier stones set aside during the building. Slab-like stones provide a level top.
Long stones should be set into wall; they help tie the wall together.
Drainage ditch must be dug on uphill side of a wall built on a slope. Fill ditch with stone rubble.
Retaining and Breast Walls
Paving With Brick or Stone, Alternatives to Blacktop
Driveways and walks made of inlaid brick or stone have proved their worth over the centuries. They are durable, attractive, and, unlike blacktop or concrete, allow the ground to breathe: moisture and nutrients can seep down to the roots of trees, and earthworms and other sub-soil creatures can continue to live undisturbed.
Brick is probably the easiest material to work with. Standard 8- by 4- by 3-inch bricks can be laid in an almost infinite variety of patterns or employed to fill rise areas with special motifs. In addition, the flat, even shape of the bricks allows tight gap-free packing.
Cobblestones-rocks smoothed by streams into roundish chunks the size of baseballs-are more lasting than bricks but make a very rough surface that is hard on the feet and almost impossible for bicycles. Belgian blocks and other dressed stone blocks are durable but expensive. Flagstones, useful and attractive for walks and patios, are too fragile for driveways.
Mortarless paving relies on a smooth underbase and the friction of individual pieces rubbing against each other to stay together. The edges of such paving should be held by some kind of frame, otherwise the outermost stones will gradually tumble away. In colonial times slabs of stone sunk upright were used to line pavements. Cinder-block slabs and railroad ties have been used in more recent days. For walks, patios, and short driveways, 1 x 4's, treated to prevent rot, will do the job. Moreover, these same edging boards can double as building frames.
Building sand makes an excellent underbase. The sand suppresses weeds, improves drainage, and infiltrates cracks, helping to lock the bricks together, yet letting them move with the earth. The result is a lasting, maintenance-free driveway.
Laying a brick walkway
1. Lay out a width of paving it iii' end of the walk by ' a row of bricks side by Drive stakes, each a l.unui'hoard width out, on it I side of bricks. Measure 'liimce between the stakes, lien drive another pair at the ilner end of walk the same lii ance apart. Stretch twine taiween each stake and its III insite at other end of the 'sal k on the outside surface i in h stake.
2. Dig along twine lengths, making vertical side trenches about 6 in. deep. Drive a series of stakes along the inside edge of each twine. Nail frame-board to the inside faces of the stakes, then dig out center of area.
3. Fill excavation 1½ in. deep with gravel, shell, or cinders. '\tler tamping, add 2 in. of unl or use 4 in. of sand alone. Smooth the sand with iii arc hed board-it improves Ininiage by making the walk higher in the center. When nuing the arch in the board, illow V in. of crown for each ) II. of pavement width.
4. Start at one end of the excavation and begin laying bricks, always working from one side to the other. Tap each brick into place with a hammer cushioned by a block of wood. The bricks should fit snugly and be even with each other. Odd shapes in a pattern are filled with p split from a whole brick. Use a pointed tool to score a line on the brick, then tap the piece with a hammer. Like scored glass, it should snap cleanly.
5. When bricks are in place, cover surface with ½ in. of sand, sweep it into the cracks, and hose down with a fine spray of water from a hose held some distance away. If necessary, repeat the process until all cracks are filled. Fill in and cover trench and framing with soil. Stay off the paved surface for several weeks, then repeat sweeping and spraying process. In shady locations weeds can be discouraged by allowing moss to grow in the cracks. Herbicides can also be used, but do not install plastic sheet under the brick to inhibit weeds. It will interfere with drainage and increase the chances of frost damage in colder areas.
---------- Interlocking paving patterns are the most durable. Straight, or running, bond (left), herringbone (center), and basket weave (right) are classic examples. For driveways, two rows of thick, flat-topped rocks are sometimes added as auto wheel tracks.
Gravel and stone pavements
Gravel (or pebble, shell, or cinder) paving should he at least 3 in. thick. Usually wood or concrete framing is used, but occasionally the paving is edged with bricks buried vertically in the ground so that only 1 to 2 in. of each brick extends above the surface. Edging helps keep the gravel in place.
Stone paving is laid like brick. Use slabs or chunks 3 to 4 in. thick that have at least two parallel flat sides. Thick cubbies and big irregular chunks require an extra-thick sand base, Match adjacent rocks carefully to fit as closely as possible. Never lay a stone with a sharp bump on exposed side.