CHAPTER 15

Color Cement for Interior Decoration

PRACTICAL USE FOR COLOR CEMENT inside the home is one of the greatest possibilities with color cement as a handicraft. It enables the home builder, the art student, or the busy housewife who has some idea of decoration, to plan and execute durable tiles or panels for the floor, walls or fireplaces, and to execute them with but little space and equipment.

TO MAKE TILES FOR THE FLOOR, the tiles should be made in flat surfaces and without relief parts that will project so as to become worn from being walked upon. For floor surfaces pressed tiles are better than poured tiles. Manufacturers of common cement tiles for architectural purposes produce them in presses with several tons pressure. The craftsman can secure very good pressed effects by using backing cement that has very little moisture in it and tapping it in well, using a block of wood and a mallet. The retaining sides of the mold should be of wood or of some durable material that will withstand the pressure, and hold together firmly.

POURED TILES FOR FLOOR USE made from a strong mixture of sand and cement and with a small proportion of color will be found to be durable. One or two coatings of shellac and a covering of floor wax will further increase the durability of the wearing surface.

PLAIN TILES FOR FLOOR USE can be used with decorated tile and various interesting patterns can be made (a few of which are shown) by interspersing the tile in different arrangements. A glazed tile can be made and used as a variation in combination with mat finish or dull finish tiles. Several small tiles may be used to fill a space and produce patterns in contrast to larger tiles. It will be found that with a little design arrangement many interesting floor arrangements can be made with tiles.

WHERE A LARGE NUMBER OF TILES ARE TO BE MADE several molds in plaster-of-Paris should be made and a large quantity of color mixed at once, and the first color placed in each tile consecutively and then the next color, until all the colors have been placed in the six, eight, ten or whatever number of molds is being made at the same operation. After the color has set, the backing mixture of concrete is made and poured into all the tiles.

A TEMPLET PATTERN MOLD for floor tiles is made by cutting templets from either cardboard or linoleum with slightly tapering sides and gluing these into position to produce the design. The templets should duplicate the portions of a design and the design should be the first step in the problem to be solved.

THE DESIGN FOR TEMPLET PATTERNS should be simple in form and division. Geometric patterns and straight line forms are the best for use. Good divisions of squares and rectangles and these divisions changed slightly to floral or leaf shapes should be as far as any elaboration should go.

AFTER THE TEMPLET PATTERN IS CUT it is assembled and glued into position on another card or glass surface and given two coats of shellac. It is then placed within the retaining bars and a cast is made in plaster. This cast in plaster is afterwards shellaced and becomes the mold for casting the cement tile.

TO CAST THE CEMENT TILE the colors selected from parts of the design are first mixed and placed into the mold. After the colors have been all placed and permitted to harden, they are backed with a mixture of neat cement and color which is next backed up with a concrete mixture and then permitted to dry for three days. After being hardened in water for several days after its removal from the mold, it is then ready to be cemented in position for floor use.

THE BACK FINISH OF WALL TILES should have countersunk spaces to permit a good grip or hold of the mortar that will be used to hold the tile in position. These grip holds can be made by cutting four small rectangular sections of cardboard and pressing them closely together into the back of the tile after the last layer of cement has been poured. After the cement has dried thoroughly and the tile is ready to be removed from its mold, these cards can be easily removed.

TO USE WALL TILES they should always be immersed in water before the mortar is applied. This prevents the moisture being absorbed out of the mortar by a dry tile and assures better sticking of the tile to a perpendicular surface.

TO MAKE GOOD MORTAR, building lime is placed in a mixing box or bucket and water poured over it. Next day it can be taken and mixed with sand until a rich, thick plaster results. To this add one-quarter or one-eighth part of Portland cement to make it strong.

TO APPLY TILES TO AN UPRIGHT SURFACE, spray the brick or rock surface with water. This can be done with a whisk broom or a large brush. A cloth immersed into water and dabbed onto the surface will serve very well. The tile which has been placed in a bucket of water to absorb moisture is then covered with mortar on the reverse side. The surface of the wall or fire mantel to receive the tile is also covered with a layer of mortar and the tile is pressed into the mortar, causing the two layers (the one on the tile and the one on the wall) to adhere to each other.

TO CONNECT TILES ONTO AN OLD CEMENT SURFACE the following method should be used: Clean the old cement surface well with a brush and water, removing the dirt and dust. Sprinkle a thin layer of neat cement onto this surface while the floor is still moist. Work this neat cement into the surface well, pressing it and working it with a flat trowel. Onto this add a layer of strong mixture cement into which the tiles are pressed.

TO FINISH A TILE FLOOR the spaces between the tiles are filled with cement; a small narrow cement trowel or strip of metal is passed over the strip to smooth the cement in between the tiles. After the first day the tiles and entire surface should be sprinkled with water to insure good hardening of the cement.

THE SPACES BETWEEN THE TILES can vary in width, depending upon the size of the tiles. A half-inch space of cement between six-inch tiles is a good average. A tile surface either upright or flat looks better with a liberal space between the tiles than where too close a connection is attempted. The tiles also look more interesting if the cement in between is left a little lower than the surface of the tile.

A color may be added to the cement used between the tiles, creating a pleasing contrast in color and values. This color may be a thin coating of color cement and need not be used throughout the entire cement section.

TO SECURE A LEVEL TILE FLOOR with the color cement tiles, the under layer of cement into which the tiles are placed should not be a wet mixture of cement but a mixture of cement and sand that is a little more moist than wet sand. The tiles are then pressed onto this layer, more of the moist cement being pressed under the tiles until the tiles are level with each other. To test the level surface a straight edged board is placed straight edge downward along the surface. If it rocks on any part of the surface, that part should be pressed downward or lowered by the removal of some of the cement. If parts are too low, they will show a light opening underneath the leveling edge and should be built up.

After the tiles are all level, the spaces between are filled with a soft mixture of cement and finished smooth.

TILES FOR INSERTS IN WALL PANELS can be made in the same way as described in the chapter on Tiles, excepting that they may be made thinner to conform with the thickness of the wood or other surface to which they will be added.

Where the wood or wall surface is grayed or toned with a paint wash or tint, the tint can be carried over the tile insert which will help the unity of the tile with the wall.

COLOR CEMENT TILES FOR FURNITURE INSERTS can be made in colors to harmonize with the wood background. The surface finish given the wood, whether wax or gray tone, can be also applied to the tile. The tiles may be applied to boxes, chairbacks, flower stands so that they become the bright spot of color motif to a design produced by the pattern of the wood, or a carved or relief enrichment on the surface.

UNIT TILES FOR WALL SURFACES can be made and planned so that various arrangements can be made by using the same motifs or elements. These elements can be combined into a group that may be inserted into an over mantel or into a wall or corridor space. Unit tiles admit of arranging a vertical or a horizontal border or of combining both borders each produced with the same motifs.

COLOR TILE BORDERS for plain cement floors will make an otherwise plain floor a thing of beauty. A series of tiles for the border can be made and special tiles for the corner arranged. The whole series can then be set at the same time that the center plain gray or tinted portion of cement is spread.

CEMENT FLOOR ABRASION CAN BE AVOIDED by dampening the cement as it hardens and spraying water onto it regularly once or twice a day after the first day for a period of five to seven days.

Abrasion or powdering of cement floors indoors often occurs because of prematurely drying when constructed. Where walks out-of-doors are benefited by the dew or moisture at night, inside floors do not receive this moisture and often dry too rapidly.

To remedy the abrasion, or powdering of cement floors, wash the floor thoroughly with clean water removing all dirt and particles with a stiff scrub brush. After the surface has dried, apply a solution of one part water-glass (sodium silicate) of 40 degrees Baumé and three to five parts water, the water depending upon the absorbing quality of the cement. This mixture is applied with a large brush and should be mixed well and used within an hour. When this has dried mop the surface with clean water and repeat the wash of water-glass three times, letting the floor dry after each operation.

The silicate penetrates the pores, comes in contact with the other alkalies in the concrete, forming an insoluble and very hard material, preventing dusting and makes a better wearing floor.