BUILDING WITH CONCRETE MASONRY

[Music] here is a familiar scene another truckload of concrete masonry units often called concrete block will soon be on its way to some construction job millions of concrete masonry units like these are made each year they are used to construct all types of buildings on farms and in cities let's have a look at a few of the many buildings constructed with concrete masonry walls here a fine new onion storage building is rapidly going up how would you like to live in this cozy little house the gleaming white walls are built of concrete masonry and have been finished with white Portland cement paint another good-looking house with concrete masonry walls when built with concrete floors such houses are fire safe as well as staunch and longlasting what farmer would not be proud of this fine set of buildings the granery hog house feed room and Beef Cattle Barn are all constructed of concrete masonary units there will be little maintenance expense on these structures let's have a second look at the Beef Cattle barn with its sturdy fire safe concrete masonry walls this concrete Dairy Barn is in tiptop shape after 30 years of continuous use Mau floors are of fire safe Concrete Construction concrete masonry is the choice of many farmers for building egg laying houses Brer houses and houses for raising Broiler chicks such houses are readily kept dry and of even temperatures parasites are easily controlled a central hog House of concrete masonry provides the much desired sanitary comfortable quarters for farrowing early spring pigs concrete paved yards on both sides of the building help make this an efficient plant for producing pork many farmers are selecting concrete masonry as the most suitable material for constructing sheds for their expensive Farm operating machinery and equipment here is a typical Implement shed there's a farm shop on one end where necessary repair work can be done to ailing farm machinery this neat looking concrete masonry building is a storage and packing Barn for truck crops here produce is sorted graded packed and made ready for shipment to Market old barns are given a new lease on life by cutting off the lower rotted portion of the building and replacing it with concrete foundation and concrete masonry walls thousands of old barns need this kind of a facelifting operation who has not seen a concrete masonry milk house economical to build and economical to maintain they are the popular choice of dairy men everywhere and of course the use of concrete masonry is not limited to farm buildings it is widely used for building all types of structures schools churches Motion Picture theaters warehouses stores and so on this modern retail farm implement establishment is a Dandy its spotless walls of concrete masonry and its streamline design make it as up to dat as tomorrow's newspaper now let's visit a typical modern plant in which concrete masonry units are made let's go inside and see what goes on the materials used in making concrete masonry units Portland cement Aggregate and water are carefully weighed or proportioned there is no guess work all batches are exactly alike now after being thoroughly mixed in giant mixers the freshly mixed concrete is conveyed to machines in which it is molded into concrete blocks each block comes out of the machine true to size and shape thousands of them in a day operation there are a number of types of machines in use in modern plants each designed to turn out carefully compacted accurately molded block the block are placed on racks when loaded racks are transported to curing rooms where the concrete block Harden under favorable conditions of moisture and temperature from the curing rooms the RS still loaded with block are transported to the store storage yard and now let's go out on a job and watch a couple of experienced Masons at work concrete foundation walls and footings are already in place every masonry wall should have adequate concrete footings which should be carried down to firm loadbearing soil to avoid settlement of the building in areas where ground freezes the footing should be below frost penetration in basement construction it is common practice for the concrete masonry wall to extend down to the concrete footing as you see here now let's discuss a few steps followed by builders in constructing dry basement walls concrete block are laid in cement morar all joints are well filled two coats of Portland cement plaster are applied to the outside face of the wall to make it watertight sometimes the wall or plaster is covered with asphalt a line of drain tile is placed around the footing and connected to a suitable Outlet to carry off any free water around the basement wall back fill above the drain tile with coarse gravel for good drainage an asphalt filed joint is provided around the edge of the floor where it meets the basement wall to prevent seepage in concrete masonry construction Corners are built first and used as guides in building the walls in between a heavy court is stretched tly between corners and the wall is built just inside this line the motar is placed in two separate strips this is done both for the horizontal or bed joints and for the vertical or end joints the morar comes in contact with only the face shells of the block this is known as face shell bedding and results in a dry wall because of the air space formed between the strips of mortar plenty of morar is used to make sure that joints are well filled joints average about 38 of an inch thick mortar squeezed out of the joints is carefully scraped off with the Trel and used to butter the ends of the block Masons often set up several blocks as shown and apply them morar for end joints the buttered block are picked up and laid in the wall not once does the Mason lay down his Trel how is that for efficiency some Builders butter both ends of the block to make sure that the vertical joints will be completely filled with morar when the mortar has become quite stiff the joints are tooled or finished various tools are used for this purpose the Masons on this job are using one edge of a piece of board about 1 and 1/2 in square and 3 ft long as a jointer other Masons use a rounded or v-shaped steel Joiner the tooling operation compresses the mortar in the joints and leaves the joints smooth and weathertight mortar pressed out along the edges is trimmed off with a few depth Strokes of the Trel and this is how a well-built concrete masonry wall looks after the joints have been tooled it's a really swell job of workmanship a good Mason is particular about the kind of mortar he uses he wants morar that is plastic that spreads easily that handles well under his Trel look closely at the mortar as the Mason places a block when mortar squeezes out like this the joints are well filled sand and cement are accurately proportioned shovel fulls of sand are counted each shovel full is the same size this is a good mortar sand clean and with the particles varying in size from fine to coarse all of it passes through a screen with eight meshes to the inch in making mortar the proportions of cement sand and other ingredients are are varied according to the type of wall and exposure for laying concrete masonry walls subject to average loading and exposure conditions such as the building being erected here Masons commonly use a mortar made of one volume of masonry cement and between two and three volumes of damp loose mortar sand or one volume of Portland cement and between one and one and a qu volumes of hydrated lime or lime putty and between four and six volumes of damp loose mortar sand whatever kind of morar is used it must be thoroughly mixed and the proper amount of water added to produce a plastic workable mixture I know you're anxious to know more about building with concrete masonry so let's go back to the wall again we saw how corners built first let's watch the skill this Mason displays in building a corner the first course is built out three or four blocks long from the corner the second course is half a block shorter than the first course the third a half block shorter than the second thus the corners are stepped off until only the corner block is laid note how frequently the Mason uses his level to see that the wall is straight and Plum the corner Block in each course is set first great care is taken to see that this block is set Plum and level the opposite corner is built in the same way and the two corners are used as guides in building intervening walls frame for doors and windows are carefully set plumbed and braced in position wall construction then proceeds as before the walls and frames are firmly tied together by anchor bolts passing through the frames into mortar joints pre-cast concrete window sills are made in a plant and delivered to the job ready to be set in the wall they're set in water and carefully leveled there are sizes of Sills to fit all windows they give the wall a neat appearance now after the walls are carried up level with the tops of the door and window frames pre-cast concrete lentil are set in place they are reinforced concrete beams which bridge over the openings and carry the weight of the wall floor and roof above them a plank window frame has been used here here is one way to install box frames for a double hung windows at your left the box frame is in place while on your right is an opening in which the frame will be inserted a special Jam block is used on both sides of the window openings the block is made with a notch or cutout in one end into which the box frame fits metal sash are readily built into concrete masonry walls windowed Jam block have recesses in which the fins of the sash extend a wood plate is bolted to the top of the wall to it roof rafter or ceiling joists are nailed plates are firmly anchored to the wall by bolts placed about 4 ft apart bolts about 16 in long are used the cores into which the bolts are inserted are stopped up about 13 in below the top of the wall with wads of newspaper some water is placed in the core after which the bolt is put in with the threaded end projecting about 2 and 1/2 in above the wall filling of the core with mortar is then continued to the top of the wall after the concrete hardens around the anchor Bolt the plate is is bolted down here is a small section of the completed wall the block are carefully laid joints are straight are of uniform thickness and have been carefully pointed many farm and City buildings are built in this manner with no other finish many other interesting wall finishes are available in this wall block of two different heights have been used in a simple pattern all joints have been toed and the surface finished with two coats of white Portland cement paint another interesting painted wall the tooled horizontal joints Stand Out boldly the rubbed vertical joints are subdued this wall treatment accentuates horizontal lines painting concrete masonry walls is an interesting job Portland cement paint comes in powder form it is mixed with water on the job a wide shallow pan is best for this purpose water is put in first and then the paint powder these are thoroughly mixed together a hand beater such as is found in most kitchens makes an excellent mixing tool the wall to be painted is first uniformly dampened with water it is usually applied in the form of a fine mist or spray this wetting is done a few minutes before the paint is put on mted joints are covered first with the cement paint the paint is scrubbed into the wall surface in order to completely fill all the tiny openings Portland cement paint serves both as a decorative covering and as a seal coat to keep out rain paint can be any color desired the lighter tints are usually the most satisfactory the brush recommended for applying cement paint has short stiff bristles it has good paint carrying capacity cement paint hardens best if kept moist for 24 hours after applying wetting is begun as soon as the paint is hard enough not to pit or wash when sprayed with water and here's another variation course Heights are about 6 in horizontal joints have been tooled this wall also has 6-in coar Heights all the joints have been tooled concrete masonry is widely used as a backing for Brick facing here is a wall 8 in thick made up of a 4-in concrete block backup and a 4in brick facing each seventh course of brick is a header course bonding the facing to the backing another wall with a brick facing but here the backing is made up of a header block 8 in thick and a 4-in brick facing forming a 12-in wall header block have offsets in them about 4 in wide and 1 and 1/2 in deep into which the header brick project to provide bond between facing and backing we hope you've enjoyed seeing this picture Illustrated important steps in building with concrete masonry as practiced by good Masons would you like a series of drawings illustrating details of construction you can get them by writing to the Portland cement Association and asking for a free copy of building with concrete Masonry [Music]