BONDS AND MORTAR JOINTS Their Influence on Brickwork By J. PARKER B. FISKE, S.B. No. 25 Copyright 1912 J. PARKER B. FISKE Detail of Mosaic Panel “Tapestry" Brick House at Oyster Bay, N. Y. For several decades the unfortunate practice has existed in America, of laying face brick in the wall so as to show only the “stretcher” or long face of the brick, without exposing the headers to view. Lovers of good brickwork may well rejoice that this custom is rapidly passing away and that the value and importance of “bonds in brickwork” are now rapidly asserting themselves. In using the word “bond” we refer to the pattern which is worked in brick and mortar on the face of the wall, in preference to its other but wholly different usage, which signifies the manner in which the face wall is con¬ nected to the rough brickwork or “backing-up” wall. Many text-books and articles on bricklaying have been published from time to time but different authors give differ¬ ent names to the same thing and the same name to different things, thus producing much confusion. We believe that the terms herein given are those used by the best authorities on the subject. The most common of the bonds used in this country is known as the “Running Bond” and is illustrated herewith. In this form of brickwork no “headers” are allowed to show in the face of the wall, except where the building laws make it manda¬ tory to “tie in” the face wall to the “backing-up” wall with header brick; under these conditions every fifth or sixth course of the face brickwork is made entirely of headers. In either case no attempt Running Bond 3 fuss Flemish Bond is made to incorporate any pattern or design into the face of the wall. It is the simplest and at the same time the least effective way of laying brick. It discards all chance of ornamentation in the “field of the wall” and, while utilitarian, is wholly inartistic. Unless a most rigid economy makes the use of the “Running Bond” necessary, its employment is a wasted opportunity — the leaving of something undone which might have been done to beautify and adorn the structure. We find the “Flemish Bond” extensively used in the “red stretcher and black header” effect of Colonial brickwork. It is used frequently, however, with bricks of a comparatively even color and adds largely to the artistic feeling of the wall. This is particular¬ ly true where the mortar joints are “raked out,” allowing each brick to stand out by itself. It attains its greatest charm when used with brick which vary in color, where the same proportion of light and dark shades appears in both headers and stretchers, thus dissipating the disagreeable checkered effect so often seen in Flemish Bond work. The “Double Stretcher Flemish Bond” has been used in some of the best brickwork in America and is a very pleasing combination of the two bonds previously mentioned. Where the headers are different in shade from the stretchers, this bond produces vertical stripes which accent the height of the wall. The “English Bond" is particularly appropriate for the English style of house now popular in many parts of America. The greater part of England’s best brickwork is laid in this manner and, wherever used in this country, the “English Bond” has given added interest and sentiment to our brickwork. Preeminently artistic and filled with interesting possibilities is the “Dutch Bond.” Ap pea ring first in the fifteenth and sixteenth century construction of Belgium and Holland, it is now found in general use in the finer work of the Low Countries. From the fact that it has been used here and there in England, it is called by some, Double Stretcher Flemish Bond at English Bond although we believe illogically, the “Eng¬ lish Cross Bond." Like the “ English Bond," it consists of alternate horizontal courses of all stretchers and all headers, but differs from it in its arrangement of the alternate stretcher courses. By reference to the accompanying illustrations it will be seen that the “English Bond” has the stretchers of the third, fifth, seventh, and succeeding alternate courses directly over the stretchers of the first course, while in the “Dutch Bond" the stretchers of the third and seventh courses break joints with the stretch¬ ers of the first and fifth courses, and so on. Nothing better illustrates the possibilities of art in brickwork than the instant transformation of the entire appearance of a wall by this simple change. The “English Bond" is picturesque and strong, it is true, but to the artist it is largely a meaningless mass of brick and mortar. The mere rearrangement of the stretchers which the Dutch employ throws continuous diagonal lines across the face of the wall, produc¬ ing a diaper pat¬ tern, the strength of which is de¬ pendent upon the width and color of the mortar joint. Without adding materially to the cost it gives just that touch of art which is so neces¬ sary for the relief of blank wall spaces. It is refreshing to notice that the brick-designers of our country are availing themselves of this simple and delightful means of decorating wall surfaces which otherwise would lack beauty and interest, and that they are accomplishing these results by a legitimate use of the constructive material itself without the injection of any “foreign" decoration. Dutch Bond 5 « TDi!© Ofc'fiai? JoDGoG Interior—Kaschaner Thor—Kum, Persia. In much of our best American brickwork we are now using mortar joints from one-half inch to one inch in thickness, constituting from 15 to 30 per cent, of the entire wall surface. If a wide mortar joint is of appropriate color and texture, it adds greatly to the beauty of the wall; if otherwise, it is a blemish. One has but to look about him to see numberless instances where the mortar has well-nigh ruined an otherwise good piece of brickwork. For a narrow joint, a mortar made of fine sand, cement and lime answers all the requirements. For a wide joint, such mortar is entirely unsatisfac¬ tory. It is soft and pasty, squeezing out of the joints before it is set, due to the weight of the brick, and thereby greatly hindering the rapid progress of the work. Being of a sticky nature, it smears the face of the brick and usually ruins the finished effect. Because of these troubles, some bricklayers object to the wide mortar joint, claiming that brick cannot be thus laid either satisfactorily or economically. These troubles have invariably arisen from the use of the wrong kind of mortar. If the following directions are carefully followed, we do not hesitate to say with all possible emphasis that perfectly satisfactory results will be obtained, not only in the character of the finished work, but in its cost. Practical experience has repeatedly demonstrated that, with the proper kind of mortar, brick can be laid with a wide, rough joint even more rapidly and economically than with the narrow, highly finished joint. G COMPOSITION OF THE MORTAR Mortar for a wide joint, that is to say, three-eighths of an inch or more, should contain a liberal proportion of fine pebbles known to the trade as “grit,” good coarse sand, Portland cement, a small amount of lime putty or hydrated lime and whatever coloring matter is desired. The following description of materials for wide mortar joints may be useful for a clear understanding of this matter: “Grit.” — This material consists of pebbles varying from 1-32 of an inch in diameter to a diameter about equal to one-half the width of the joint, that is to say, “grit” for a half-inch joint should contain pebbles not over 1-4 inch in diameter. This “grit” should be screened free from sand in order that a measured amount of both “grit” and sand may be used in the mortar. The practice of using a mixture of sand and pebbles as the material comes from the ordinary sandbank is usually unsatisfactory, owing to the varying proportion of “grit” thus obtained. The proper use of “grit” is the key-note to the wide mortar joint ques¬ tion. “Grit” gives the mortar a short, granular consistency, making it impossible to smear the face of the brick. Moreover, it gives the mortar a certain “body,” comparable in a degree to concrete, making it, even when soft, capable of sustaining a heavy load. Thus, with a mortar containing the proper proportion of “grit,” one course of brick after another can be laid rapidly and the mortar will not squeeze out of the lower courses even while it is still soft. To omit “grit” in the mixing of the mortar is to invite continual trouble during the progress of the work and final failure in its finished appearance. Sand. — Unless a very white joint is desired, any good ordinary bank sand or “native” sand is perfectly satisfactory, provided it is coarse and sharp. Sand coming from salt water beaches should absolutely be 'prohibited , as the salt often effloresces from the mortar joint in the spring of the year, thereby causing very disagreeable disfigurement. Cement. — Any first-class Portland cement is satisfactory. Lime. — Where lime putty is used, it should be thoroughly slaked until all lumps are disintegrated. On small work and in certain localities the use of dry hydrated lime will be found not only convenient, but economical. Coloring Matter. —This must be determined to suit each individual case, according to the taste of the designer. The formulae given on the following pages provide for “French’s” mortar colors. Other makes may be used, but the quantity must be determined in accordance with the color value of the particular material used. 7 MIXING OF THE MORTAR We venture the statement that nine-tenths of the unsightly patches and blotches in mortar joints can be traced directly to an improper method of mixing or to gross carelessness on the part of the mixer. For wide mortar joints the common practice of slaking the lime and mixing with sand in a large storage bed in the early stages of the work, and then “gauging” small lots with cement from time to time as mortar is required by the bricklayer, should absolutely be prohibited. While this method may serve fairly well in the case of narrow and inconspicuous joints, it is almost certain to produce streaks and patches of varying color and texture in the case of wide joints. We have frequently seen mortar joints in the same wall varying from white to a mouse-gray, owing to the fact that the mortar-mixer did not measure his materials, but “gauged" them with his eye or “judgment.” When the mixer gets the mortar too soft it is a common practice to put in more cement to stiffen it, the result being that no two batches of mortar are alike in color. With such a “hit or miss" method, satisfactory results are impossible. The ingredients of each batch of mortar should be accurately measured. Too much importance cannot be attached to this rule. Marc Eidlitz &Son, Bldrs. Donn Barber, Archt. A STUDY TO DETERMINE THE BEST MORTAR JOINT FOR THE LOTOS CLUB HOUSE, NEW YORK This panel is built with three different mixtures of mortar and finished partly “ raked out ” and partly “rough cut flush.” Notice (even in the picture) how a variation of mortar alters the whole appear¬ ance of the brickwork. Unfortunately this spotted effect is seen too often in a finished building. 8 DETAIL—HOUSE AT OYSTER BAY, L. I. Mortar joint one inch thick. “All difficulties vanish with proper materials and a proper method of mixing.” Suitable measuring boxes should be provided and their careful use should be insisted upon. A little care at the mortar bed will be repaid many times over by the improved appearance of the building in which the mortar joint forms so important a part. We respectfully suggest that the architect’s specifications in¬ clude the following paragraph: “The ‘grit,’ sand, cement, lime putty (or hydrated lime) and coloring matter shall be accuratelv measured in suitable measuring boxes, furnished by the contractor and approv¬ ed by the architect. 1/ The ‘gauging’ of lime mortar with cement shall be absolutely pro¬ hibited/’ Upon request, we will furnish a placard of instructions printed in large type on linen, to be posted near the mortar bed. COLORS OF MORTAR JOINTS Generally speaking, we recommend the following colors of joints for Tapestry’' Brick of our several groups: Red" Group. Cream grav mortar. .... Formula “P” or Dark reddish brown mortar. ....Formula “B” Gray” Group. Dark gray mortar. . . . .Formula “N” Golden” Group . . Cream grav mortar. . . . Formula “P” or Light gray mortar. . . . .Formula “L” 9 FORMULAE FOR MORTAR MIXING FOR “TAPESTRY” BRICKWORK Note No. 1. — The following formulae are based upon the use of a 16- quart bucket (the unit of measurement for small batches) and a Portland cement barrel (the unit of measurement for large batches), the average capacity of which is 96 quarts. Note No. 2. — The coloring matter to be used in connection with these formulae is French's Peerless Mortar Color (paste) and French's Cement Mortar Color (powder), manufactured by Samuel H. French & Co., Philadelphia, Pa. These formulae have been thoroughly tested with these particular color¬ ing materials, which should therefore be used to secure the desired results. Note No. 3. — In computing these formulae, the U. S. Standard Liquid Measure has been used. Note No. 4.—Lime Putty may be used instead of “Hydrated Lime." FORMULA “B”—FOR DARK BROWN MORTAR Materials Proportions 34 inch Grit Coarse Sand Portland Cement Hydrated Lime Yellow (Powder) Brown (Paste) Black (Paste) 2 parts 5 “ i part 34 “ 34 “ X “ Vao “ Quantities for Small Batches 4 Buckets i bucket io% quarts 10 % “ 5 gills Quantities for Regular Work 2 Barrels 5 “ i barrel 34 “ 32 quarts OO << FORMULA “ L ’’—FOR Materials 34 inch Grit Coarse Sand Portland Cement Hydrated Lime Proportions 2 parts 1 part % “ LIGHT GRAY MORTAR Quantities for Small Batches 4 Buckets 10 “ 2 “ 1 bucket Quantities for Regular Work 2 Barrels 5 “ 1 barrel % “ FORMULA “N”—FOR DARK GRAY MORTAR Materials Proportions 34 inch Grit 2 parts Coarse Sand 5 << Portland Cement 1 part Hydrated Lime 34 << Yellow (Powder) V12 u Black (Paste) Vit> << Quantities for Small Batches 4 Buckets 1 bucket 2% quarts O Quantities for Regular Work 2 Barrels 5 “ 1 barrel % “ 8 quarts 6 FORMULA “P”—FOR CREAM GRAY MORTAR Materials Proportions Quantities for Small Batches Quantities for Regular Work 34 inch Grit 2 parts 4 Buckets 2 Barrels Coarse Sand 5 “ 10 “ 5 Portland Cement 1 part 2 “ 1 barrel Hydrated Lime % “ 1 bucket 34 “ Yellow (Powder) X “ 5% quarts 16 quarts 10 FINISH OF JOINTS FOR ORDINARY FACE BRICKWORK The texture and finish of a mortar joint are governed by the materials of which it is composed and by the manner in which it is treated by the bricklayer as the work progresses. In some localities a barbarous practice, known as “tucking,” still has some vogue but it is not good workmanship. It consists of raking out the joints as the brick are laid, then allowing the wall to dry, after which the “tucker” fills in the open joints with very fine, white mortar. He leaves behind him a glaring — almost glittering — wall which is anything but ar¬ tistic and which often resembles a new kitchen oilcloth. Furthermore, such work lacks permanency, as the shallow joint is particularly susceptible to frost and other weather conditions, and after a few seasons the “tucker” comes around to get another contract. As a general rule, however, the bricklayer finishes his own work and, for smooth brick, may use one of the following joints: “Struck”: made bv drawing the point of the trowel along the joint, so giving a smooth surface which is flush with the lower edge of the upper brick but slightly back of the upper edge of the lower brick. “ Weathered ”: made by draw¬ ing the point of the trowel across the joint in a slightly slanting position, so cutting off the mortar at the top of the joint, but leav¬ ing the bottom flush with the edge of the brick. “Tooled": made by using a tool known as a “jointer” with an end either half-round or “V”- sliaped. “Rodded”: made by using a straight-edge and cutting a straight line with the edge of the trowel along the top and bottom of the joint, flush with the edges of the brick. This joint is very similar to a “struck” joint, but is a somewhat finer finish. None of the above methods in common use with ordinary face brick are suitable for “ Tapestry ” Brickwork . 11 Rodded Tooled with Round End Jointer FINISH OF MORTAll JOINT FOR ‘ ‘ TAPESTRY ’ ’ BRICKWORK The texture of the mortar joint should be in harmony with the texture of the brick. It is irrational to use a rough finished brick to give texture to a wall and then to flatten that texture by using a smooth, finished joint. Therefore, the smooth joints described on the preceding page are wholly unfit for “Tapestry” Brickwork. They have been described to show what should be avoided rather than what should be chosen. The principal precaution in finishing the mortar joint in “Tapestry” Brickwork is to avoid smoothing it in any way either with a trowel or with a finishing tool. Either of the following finishes is suitable: The “raked out” joint is obtained by cutting back the partly set mortar from the face of the brickwork with the end (not the head) of a 20-penny (or larger) cut nail, the sharp edges of which will thoroughly clean the mortar from the arrises of the brick and leave the surface of the joint flat and rough. The depth of the rake should be from 1-8 inch to 1-2 inch, depending upon the amount of “shadow effect” desired. The jpoint of the trowel or a rounded tool of any kind should never be em¬ ployed for this purpose, as it tends to rub the mortar into the rough edges of the brick, giving a very untidy effect. The “rough-cut flush” joint is made by allowing the mortar to ooze out beyond the surface of the brick and then cutting off the surplus with a quick stroke of the trowel, just after the mortar begins to set. Great care should be taken in doing this work not to smooth the surface of the mortar. 12 STYLE OF FINISH FOR DIFFERENT COLORS OF “TAPESTRY” BRICK Generally speaking, we strongly recommend the following: “TAPESTRY” BRICK, “RED GROUP”: In the case of the “Cream Gray’’ Mortar the joint should be “Rough Cut Flush "; in the case of the “Dark Brownish Red" Mortar the joint should be “Raked Out" to cast a shadow. “TAPESTRY” BRICK, “GRAY GROUP”: Experience has shown that a “Rough Cut” Mortar Joint is very unde¬ sirable with gray brick, as the brick and the mortar are so nearly the same color and texture that the wall loses character and looks like a monotonous cement surface. The joint should therefore be “Raked Out.'" “TAPESTRY” BRICK, “GOLDEN GROUP”: - Unless a distinctly white joint is used, thereby setting out each brick distinctly, the joint should be “Raked Out” as in the case of “Tapestry” Brick of the “Gray Group.” METHOD OF LAYING BRICK Face Brick should invariably be laid from a scaffold from the outside of the wall, never overhand from the inside. It is impossible by the latter method to get joints of equal thickness and finish or to do good work in other respects. BRIEF SUMMARY First. Use “Grit.” Second. Measure all materials carefully. Third. Lav the brick from an outside scaffold. Fourth. Never smooth the joint. Fifth. Be sure vour mortar is not too soft. 13 TRADE MARK lill ; 06 U 6 p| SSL m - **** * - .Swsippspaisi sS- g* isgaafflS Sjr- —-* 0... ,—* ." •?• l»' >¥& ..- . /• . ,« a > '.-. - 233** - ^ m%mx S^jwwMKg REGISTERED U. S. PATENT OFFICE The Most Artistic and Permanent Building Material in the World. It is economical and suitable for any building worth building. The “Tapestry” Brick for a $7000 detached house costs only about $400. It assures a beautiful exterior without'one cent of future outlay for maintenance. It is really cheaper than wood. The satisfaction it gives can not be measured. There is only one“Tapestry” Brick. Our Trade-Mark is stamped on each brick. , Write and tell us what you are planning to build; send architects’ eleva¬ tions and our Designing and Color Department will suggest pattern work and color scheme. Send for our books, beautifully illustrated in colors. F1SKE & COMPANY, Inc., Arena Bldg., New York Promoters and Designers of Artistic Brickwork. Sole Manufacturers of “Tapestry” Brick. HENRY J. F. LUDEMAN ARCHITECT “Tapestry” is our Registered Trade Mark. It is the legal name of our Brick. It cannot be rightfully used other in connection with any Brick. To protect you against sub¬ stitution it is branded on each Brick, either on the flat side or the back. F1SKE & COMPANY, Inc Boston and New York jsMSI TpISKE fr- COMPANY INC lACE BRICKS! ESTABLISH Hire bricks) ed in 1864 Promoters and Designers of Artistic Brickwork Proprietors and Sole Manufacturers of Boston 25 Arch Street REG’DU.S.PAT. OFF New York Arena Building