It Pays to Build with Concrete True building economy is realized in concrete-cobblestone construction. Permanence and freedom from maintenance expense make its first cost the only cost. Thus it is cheapest in the end. Often first cost will be lowest because the owner can do much of the work himself during spare time or with hired help. Sand, pebbles and stone used for the walls can be obtained locally for the mere cost of hauling. The storm-proof and fire-resistive qualities of cobblestone construction make it especially desirable. So great is the strength of buildings constructed of this material that the most severe tornadoes seldom damage them. Concrete and stone likewise has no superior as a fireproof material. Since the use of firesafe materials—those which cannot start to burn—is recognized as one of the biggest aids to fire preven¬ tion, it is important that materials like concrete and stone be used whenever possible. Resale value is undoubtedly enhanced when any property is equipped with good buildings. The prospective buyer can afford to pay more for such property because upkeep expenses on buildings will be negligible. Whether the new building is a roadside market or a farm home, a suburban church or a creamery for the small town, cobblestone and concrete will be found suitable. There are no limitations to what can be done with the material with proper study and application. This cobblestone filling station was built by the owner who is seen standing by the column in the foreground. Cobblestone arches, lintels and watertables add to the interest and beauty of this bungalow. Building with Concrete and Cobblestone In the rapidly increasing use of concrete is seen a determined effort on the part of the nation to decrease its fire losses which now amount to more than half a billion dollars annually. Appalling though this figure is, losses are not confined to property damage—more than 14,000 lives are snuffed out each year by the fire demon. Protection against such losses can and is being obtained by construction with concrete, recognized the world over as a fireproofing material of the first order. The staggering losses by fire are probably exceeded by the damages caused by the agencies of rust and decay which each year cost property owners unbelievable sums. These, too, can be greatly reduced by the use of concrete construction which successfully resists the destructive action of the elements. Cobblestone work, employing native stone and concrete, satisfies both the requirements for fire-safety and permanence. Its durability and fire-safety are readily recognized from common knowledge of the materials composing its structure. Cobblestones are especially durable, having been exposed to the elements, and, therefore, freed of all softer materials. The enduring qualities of concrete, the other basic material in cobblestone work, are well known. Combined, these two produce a lasting, fire-resistive type of construction. Practically every section of the country has a supply of stones suitable for cobblestone work, making this an unusually economical type of con¬ struction. Deposited by the glaciers or as the remnants of erosion such stones are generally considered of little value and often are a detriment to the property. Cobblestone construction affords a practical means of utilizing this material. Building With Concrete 4 Stones Require No Special Treatment The stones require no special preparation for this work; sizes and shapes can vary within wide limits. General practice favors the use of medium sized stones easily grasped in one hand; large units are cum¬ brous to handle and small ones slow down speed of construction. Most builders use stones as they find them; others break them or chip the faces according to the effect desired. Fragments from stone quarries are also utilized in cobblestone construction. Colors Blend with Nature The wide range of colors and textures possible in cobblestone work lends it beauty and interest. Shades of color in stones are rarely of the brighter hues, the subdued colors of nature predominating. Unevenly weathered faces, varied sizes and colors of stones, and the irregular mortar joints characteristic of this type of work, all help to make cobblestone construction harmonize with its surroundings. Chipping often reveals shades of color not visible on the faces of the stones as they are found. Sorting of the stones for colorings or for sizes affords unlimited possi¬ bilities for varying the final effect. For the agricultural community cobblestone construction is especially useful. Cobblestone, sand and pebbles needed for this class of work are often found near the building site and can be obtained for the cost of hauling. Portland cement is obtained from the nearby supply yard as is the small amount of lumber needed for forms. The tools required are those generally used on the farm. No man need hesitate to undertake the work on account of inexperience. For example, the small brooder house shown below was erected by a man who had no previous ex¬ perience in laying cobblestone. Best results are obtained, however, when certain building practices such as outlined on the following pages are followed. and Cobblestone 5 ■ mi in 11 in 11 tin ii mi i in ■ ■ in i in 1111 tin Cobblestones, sand and pebbles collected preparatory to building a residence. Laying Out the Foundation A practical method of laying out foundations for small buildings is illustrated below. A base line marking out one side of the building, as A-B, is established, and nails are driven into the tops of the stakes to indicate the precise locations of the corners. On the line A-B locate stake F, 6 feet from A. Stake E is then driven 10 feet from F and 8 feet from A. Nails are also driven in the tops of stakes E and F. The corner E-A-F is then a right angle triangle with sides 6, 8 and 10 feet long. Side A-E extended will represent the side A-D of the building and the point D the third corner. The fourth corner C is located in a similar manner by the right triangle method. Strings are then stretched over the corner stakes and carried to batter boards as illustrated (GH, KL, MN, PR). The outline of the building having thus been determined, the corner stakes are removed and excavation commenced, either for trench or complete basement as the occasion demands. 6 Building With Concrete Solid Concrete Foundations Footings and foundation walls for cobblestone buildings are generally made of solid concrete, usu¬ ally spoken of by builders as monolithic concrete. This type of foundation is easy to build and as¬ sures that the wall load will be evenly distributed on the soil, insuring against settlement. It also provides an excellent base on which to start the cobblestone wall. Dimensions of footings vary depending upon the size and weight of the building. Under the walls of a barn, a footing 2 feet wide and 12 inches deep will ordinarily be sufficient. Residences and filling stations require footings approximately 18 inches wide and 12 inches deep. Footings 12 inches wide and 8 inches deep will serve for smaller buildings such as one-car garages, poultry houses and milk houses. Foundation walls 8 to 12 inches thick are generally ample for structures of this type. Cob¬ blestone walls are rarely made less than 8 inches thick and accordingly must have at least 8 inches of foundation wall to rest upon. For buildings without basement the sides of the foundation trench can be used for forms if the soil is of a type that does not cave readily. If, however, the earth does not stand by itself, forms like those shown in the illustration on page 7 will be required. In either case forms will be required for con¬ structing the inner wall (see illustration at the left) of the basement un¬ less that part of the structure is built of cob¬ blestone. Forms for Cobblestone Work In cobblestone con¬ struction above grade, forms are required for the inner wall only, no outer forms being need¬ ed. Two methods of building inner forms are in common use. In one method, used mostly for Forms for the foundation walls where the embankment serves as the outer form. This type of form is used for building cobblestone walls. Substantial and non-rotting corner post built with cob¬ blestone found on the farm. and Cobblestone 7 smaller jobs, the complete inner form is built before masonry work is started. In the other method the wall is built in courses, the sheathing boards against which concrete is placed being raised and used again and again until the work is completed. Forms for either method are simple in construction. Studs used for supporting form sheathing consist of 2 by 4 or 2 by 6-inch material placed not more than 3 feet apart to prevent any bulging in the finished wall. Studs should be rigidly braced with diagonal struts so that there will be no move¬ ment of the forms while the wall is being built. This method of forming is used for the foun¬ dation when the soil caves. Boards having straight edges and surfaced one side are recommended for form sheathing. The sides coming in contact with the concrete mixture should be oiled or greased to make removal easy. Where the wall is built in courses, enough boards should be on hand to permit the work to proceed without interruption yet allowing forms to remain in place long enough for the w r all to acquire sufficient strength to stand by itself. Boards 12 inches or more wide are preferable to nar¬ rower boards because they permit a greater height of wall to be built in one course. Usu¬ ally one course is built each day. In warm weather, however, the concrete will often hard¬ en quickly enough so that the forms can be raised and a second course built during the same day. To allow forms to be taken off easily and with¬ out disturbing the sup¬ ports a removable strip is Forms must be true and plumb and properly braced. Note USed aS backing at each I by 3-inch strips between form boards and studs. These per- . i i • . i mit form boards to be raised without disturbing frame work. StUQ, 3/S SilO\V II III LHC 8 Building With Concrete Cobblestone walls completed for a modern poultry house. drawing on page 7 and in the illustrations on page 13. Any piece of lum¬ ber two or three feet long, usually 1 by 2 or 1 by 3-inch material, is satis¬ factory. These strips are tacked to the studs. When the strips are removed, sheathing boards are easily taken off and raised without displacing the studs. Zk4'uprighh bo full wall I"x3 > strips- U -•*!'x / Z" boards Mix for Concrete Foundation The concrete mix recommended for foundation wall construction is 5 gallons of water per sack of cement to which such amounts of moist sand and pebbles are added as will produce a rather thick consistency. This amount of water is decreased to gallons if the sand and pebbles are wet, and increased to 6 V 2 gallons if the sand and pebbles are thor¬ oughly dry. Proportions for the first trial mix are 1 part cement to parts sand to 3)/£ parts pebbles (l-2^-3 x /i mix) using pebbles up to V /2 inches in size. It may be found that these proportions give too stiff a mix, too wet a mix or a mix that lacks smoothness and workability. These con¬ ditions can be corrected by changing slightly the proportions of sand and pebbles. Great care must Form boards have been raised for next course. Note that form be taken, however, not board is not nailed but rests on a block tacked to the side of . _ .1 1 1 the stud. to use more than the braces and Cobblestone 9 amounts of water mentioned above, because excess mixing water will re¬ sult in weak, porous concrete. Placing Concrete for Foundation Concrete should be placed in the forms within 45 minutes after mixing. It should be deposited in layers of uni¬ form depth, usually not exceeding 6 inches. When placed in the forms it should be tamped and spaded so as to cause it to settle thoroughly every¬ where in the forms and produce a dense mass. By “spading” is meant the working of a spade or chisel-edge board in the concrete and between it and the side of the forms, moving the spading tool to and fro and up and down. This working of the concrete next to the forms forces the large pebbles or stone particles away from the form face into the mass of the concrete and insures an even, dense surface when forms are removed. Smooth off the top of the foundation with shovel or trowel to provide a level base for the cobblestone wall. The foundation should be given at least one day to harden before starting the cobblestone work. An elevated water storage tank with room for general storage purposes on the ground level. Mix for Wall The cobblestone wall is laid up in a mixture of concrete which is placed with trowel or shovel, preferably both for speedy work. The concrete Rural school buildings constructed with concrete and cobblestone are strong, durable and rotproof. Walls can be constructed rapidly. 10 Building With Concrete ....... A good concrete mixture will Mixing board, box for measuring sand and pebbles, pail for have this appearance. measuring water, shovel and wheelbarrow used in building with concrete and cobblestone. mixture should be of such consistency as will permit of rapid construction. A little experience will enable the builder to determine the best degree of plasticity. The recommended concrete mix for this work is 434 gallons of water per sack of cement, with sand and pebbles in moist condition. If the sand and pebbles are dry, use 534 gallons of water, and if dripping ivet cut down the quantity to 3% gallons. Less water is specified when aggre¬ gates are in a moist condition because the moisture in the sand and pebbles is free to act upon the cement. For the first or trial batch a mixture containing one sack of cement, 234 cubic feet of sand and 234 cubic feet of pebbles (1-234*234 mix) is recommended, using pebbles up to one inch in size. It may be necessary to change the proportions of sand and pebbles somewhat to get the right degree of workability. If the above proportions give a mix which is too sloppy increase the amounts of sand and pebbles; if too dry cut down the amounts in the next batch. The size of the aggregate is limited to one inch as larger pebbles might result in faulty mortar joints between the stones. Do not change the recommended amount of water per sack of cement. Mix Thoroughly Concrete can be mixed by machine or by hand. In either case mixing must proceed until stones or pebbles are completely coated with a mortar of sand and cement. For cobblestone construction the quanti¬ ties of mortar needed are not excessive and hand mixing will probably be found satisfactory, particularly on small jobs and Cobblestone 11 where only one man is laying the stones. Where two or more men are at work it will usually pay to have a small mechanical mixer. A machine mixer will be found especially useful in mixing concrete for footings and foundation wall. Mixing should con¬ tinue for a minute and a half after all materials including water have been placed in the mixer drum. In hand mixing a platform not smaller than 8 feet by 12 feet with tight joints and smooth surface is used. A 2 by 2-inch piece or similar strip should be nailed around the outer edge to prevent waste of materials during mixing. Mixing by Hand The method of mixing generally used is as follows: Spread out the measured amount of sand on the platform; distribute the required quantity of cement evenly on top of the sand, and mix them with a square pointed shovel until the mixture is uniform in color. On the cement-sand mixture spread the measured amount of pebbles and mix thoroughly as before by turning with the shovel until the mass is of the same even color throughout. The center of the pile is then scooped out and the measured amount of w 7 ater poured slowly into the depression thus formed, the materials in the pile being gradually turned into the Steps in the work of mixing concrete by hand. Thorough mixing is necessary for best results. Precast concrete units and concrete brick are used here to form sharp true corners. 12 Building With Concrete Gauging thickness of wall. Trowel is used to Rocks should not be jammed against the form measure distance from face of form to outer face board. An appreciable amount of mortar should of wall. be between stone and form. water with shovels and gradually mixed until the cement, sand and pebbles have been thoroughly and uniformly combined and the mixture has the same color and plasticity throughout. Building the Wall In preparing materials for cobblestone construction the supply of stones is sorted, laying aside those of a suitable size, color and shape for the wall and dropping rejected pieces in the mixture when placing con¬ crete for footing and foundation walls. Always make certain that the stones are completely covered with the concrete mixture. The appear¬ ance of the wall can be varied to suit the owner depending only on the variety of materials at hand. A rough wall can be made using rocks of irregular and jagged surfaces or a smooth wall can be obtained by select¬ ing stones having flat or rounded surfaces. Further variation in effect is obtained by pointing with plain or colored mortar. Placing mortar on wall. Use shovel to deposit Spading mortar with trowel to insure that all mortar for speedy construction. spaces between stone will be completely filled. and Cobblestone 13 Tamping concrete. Use short broom handle Raking out the joints. After mortar has hardened or other tamper to insure compact concrete, somewhat the surplus is raked off face of stone and the joint pointed. Pointing should not be done when mortar is too green. As each stone is laid it is lightly tamped into place and all crevices between stones filled with concrete. Each stone must be carefully bed¬ ded in the mortar. Concrete between stones and against the form face is spaded and tamped as it is placed to insure compactness and a smooth inner surface when forms are removed. To insure a definite minimum thickness of concrete on the inner side of the cobblestone wall the handle of the trowel may be used as a gauge and none of the stones placed closer to the wood forms than the thickness of the trowel handle. The wall thickness is easily kept uniform, a simple method being to measure the distance with the trowel. Both methods are shown in the illustrations on page 12. Showing strip behind form. Note projecting Removing strip. Projecting nail has been pulled, nail in 1 bv 3 which can be readily with- allowing strip to be removed. This allows the drawn thus allowing strip to be removed. form to be taken off and raised without disturb¬ ing the uprights or studs. 14 Building With Concrete Exterior Finishes In general there are two ways of finishing the outer face of the cobble¬ stone wall. These two methods are commonly known as “pointed” and “unpointed” work. In the latter, surplus mortar is raked out with the trowel, practically no mortar being visible in the finished wall. In pointed work a special mortar for filling crevises between stones serves to seal the joints and produce a more finished appearance. Mix one part cement with three parts sand for best results with such mortar, no lime being required. Mineral coloring ma¬ terials, finely ground and thoroughly distributed in the mortar, may be used to produce colored joints. The amount c , , , . , A . _ rrames tor door and window openings must of coloring matter used must be only be rigidly braced in place. Note the appearance , . l . * . l • 1 , from inside ot this cobblestone creamery. enough to secure the tint desired, exact amounts for various tints being determined by experiment or trial. Section through finished wall. Note how closelv the concrete and stone are bonded together and the smooth surface obtained on the inner wall. Where concrete floors are desired they are generally built after the walls are completed. If the soil on which the floor is laid is well drained the concrete can be placed directly on it after all refuse, grass roots and similar materials have been removed and the ground has been leveled off and well compacted. If drainage is poor and soil water is likely to be present a six- inch fill of cinders or gravel, well com¬ pacted, is recommended. The floor slab should preferably be placed in strips four or five feet wide and at least four inches in thickness, using the same mixture of concrete throughout. This is known as one- course construction. The forms used for separating the area into sections, usually 2 by 4’s set on edge and held in place by stakes, also provide a guide for leveling off the concrete and Cobblestone 15 MiiiiiiiiiiiiiiiiMiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiMiMiiMiiiiHiniiHiiiiiiiiiiiMiiiHiiiiiiiiiiiiniiiiniiiiiMiMiiiiiiitiniiniMiiiiiiniiiiiiMiiniiiiiniiiiiiiiiiiiiiiniiiiiiiiiniiiiiiniiiiniiiiiiiiiiiiiiiiHiniiiiniiiimiiiniiiiiinmiMiiiiii at the desired slope or level. This is done by means of a straight edge (a 1 by 6-inch board is satisfactory) resting on the forms as a guide. After concrete has hardened somewhat, but is still workable, the surface is compacted and worked with a wooden float to give it an even surface. Too much troweling is to be avoided. Short pieces of plank are sometimes used by the finisher to kneel on in working over the fresh concrete. Other Construction Details Window and door openings are provided with sills and lintels as in any other type of masonry construction. Frames for doors and windows using either plank or box frames as required are set in place and braced before the wall is built, with bolts or spikes projecting into the wall to provide anchorage. Good practice includes priming of these frames before they are used. The plate for the roof is securely anchored into the cobblestone wall by means of bolts placed in the top course of the wall as laid Cttring If cobblestone walls are exposed to sun and wind before hardening, much of the water necessary to curing will evaporate and the concrete will simply dry out. This condition may occur when forms are moved up as the wall is built. To keep the wall moist and to guard it against rapid evaporation under these conditions, moist canvas or burlap covering is placed over the wall. This material is kept moist during the early hardening period or approximately ten days. Floors are cured by covering with earth or sand as soon as concrete has hardened sufficiently to prevent damage to the surface. This cover¬ ing is kept moist for 10 days by sprinkling. At the end of this time the floor can be put into service. Cobblestone construction not only proved economical but added beauty and strength to the design of this firesafe filling station and roadside hotel. Cutting Costsl In countless ways concrete can help you cut costs, be¬ cause it is permanent, firesafe and sanitary—therefore economical. By starting now to use concrete for new structures and repairs you can gradually cut your costs—increasing your profits. Check below the subjects upon which you want definite information and mail the coupon. Free booklets will be sent immediately. PORTLAND CEMENT ASSOCIATION A National Organization to Improve and Extend the Uses of Concrete District Offices at Atlanta Birmingham Boston Chicago Columbus, O. Dallas Denver Des Moines Detroit Helena, Mont. Indianapolis Jacksonville Kansas City Lincoln, Nebr. Los Angeles Milwaukee Minneapolis Nashville New Orleans New York Oklahoma City Parkersburg Philadelphia Pittsburgh Portland, Oreg. Richmond, Va. Salt Lake City San Francisco Seattle St. Louis Vancouver, B. C. Washington, D. C. PORTLAND CEMENT ASSOCIATION (Address office nearest you) Please send me free information on: □ Barns □ Barn floors □ Basement □ Cisterns □ Feeding floors □ Fence posts [3] Floors □ Foundations □ Garages □ Houses □ Septic tanks □ Sidewalks □ Silos □ Troughs J Water supply tanks Name. Street No. or R. F. D. City.State. Printed in U. S. A. F 19—25M—3-28—8—16P