Brick Veneered
Hollow-tile wall
In order to prevent the penetration of moisture the mason should butter all joints on the inside and outside edges, leaving an empty space between, in order to insulate against the transmission of moisture through the joint. To prevent the collection of mortar in the cells of the tile, due to droppings during construction, the spreading of metal lath over the top of each course of tile will accomplish this and also make the strength of the wall greater. Although it is often recommended that hollow-tile be plastered directly upon the interior, yet this is not safe in those sections of the country where there are driving rain-storms. For this reason it is advisable to fur them on the interior. It is also recommended that a waterproofing compound be added to the stucco applied to the exterior. Another fact should be observed: namely, that all door and window frames, since they are of wood, will tend to shrink and thus open up the joints and permit the leakage of rain-water. Oakum should be stuffed behind all brick moulds to prevent this. Care should also be taken to make drips under all sills, so that no water will leak into the interior of the wall. All belt courses should also have steep washes. Stucco should not be carried down to the grade level, but a course of solid material, like brick, concrete, or stone, should be built at this point.
VENEERING
It is sometimes customary to veneer walls of hollow-tile with brick, especially those tiles which are of the interlocking type, since a better bond can be secured. In any case, any brick veneer should be bonded to the backing with a row of headers every 16 inches, or be attached with metal ties. This veneering should not be considered as part of the required thickness of wall.
WALL THICKNESS
The thickness of hollow-tile walls should be the same as for walls of brick. The construction of light 10-inch and 8-inch walls, while strong enough as a substitute for a frame dwelling, is not strong against weather or fire. The only justification for thin walls is the slightly reduced cost of materials. Hollow blocks, as a rule, are not used for foundations, although they are satisfactory under buildings not higher than 40 feet. It is better to fill such walls with concrete and waterproof them on the exterior.
Concrete House
The development of the concrete house has been stimulated by large corporations erecting towns of them in one locality. The erection of concrete houses by individual builders cannot, as a rule, follow those systems which are adapted to group construction. The use of large precast units may be satisfactory for a development of a hundred or more houses, but it is not economical for a single operation. The use of heavy steel forms for casting monolithic houses of concrete, while under certain favorable labor conditions may be satisfactory for a small job, yet as a rule is better adapted to large enterprises. Such steel forms are represented by the Lambie forms and the Hydraulic forms. Even wood forms of heavy construction, like those used in the Ingersoll system in work at Union and Phillipsburg, are not adapted to an operation involving less than fifty identical houses. Another system, combining both the precast and the cast-in-place work, called the Simpsoncraft system, is not economical for small operations. This uses thin precast slabs for walls and floors, and precast concrete beams. The precast parts are tied together by casting in place reinforced studs of concrete.
Practically the only available systems which are useful for the small operation are (1) monolithic houses, built with light, portable steel forms or wooden forms, and (2) the concrete block house.