ROOF GUTTERS AND WASTE-PIPES.
Roof Guilers and conductors, or waste-pipes, were formerly constructed of lead, copper, or tin, but recently tinned or galvanized iron or zinc has been almost exclusively employed. Gutters may be arranged in various ways, but care should always be observed that they have a fall of about one to the hundred, to facilitate the draining of the water.
Hanging simplest but least elegant style is the hanging semicylindrical gutter, shoi.vn in Figure 15 (pi. 7), which is suspended by means of iron straps directly beneath the eaves in front of the upper parts of the cornice. The appearance of the cornice is thereby injured, especially as the gutter must necessarily be set in a slanting direction. Figure r6tz exhibits the highest, and Figure r6b the lowest, point of the gutter, while Figure 15 shows the fastenings or supports, which are about 2 feet apart. The metal in this form of gutter is rolled up on the outer edge and con nected with the iron by small metal straps soldered on. A much better form of glitter is so placed over the lower courses of the roofing, and like wise secured by straps, that the next courses overlap it; in this style the glitter lies with its rear surface against the roof-planking, but in other respects the arrangement is similar to that of the banging gutter.
The (fig. 17) is the form to be preferred. It is concealed from view by an uprig-lit fillet in front, which forms a k-ind of copinp.-, over the cornice and prevents it from being seen from the outside. This glitter is iisually made roughly in wood and then lined with zinc.' It is clearly shown in the illustration, which also exhibits the opening into the con ductor or waste-pipe, an accessory piece being added, and also a strainer, to prevent any obstructive matter from entering the waste-pipe. The par allel or box-gutter is necessary next to parapets, where a curb roof is formed, and is useful in valleys of small roofs where there is sufficient depth. When the walls are thick, it is iisnal to place this form of glitter below the timbers of the roof, whereby they are kept dry and damage from overflow is avoided. This can also be done by using a projecting cornice,
the glitter being formed on it in place of a real blocking course. When the edges of the metal sheeting are turned up against the side of the chim ney- shaft or the back of a blocking course, instead of being turned into the joints of brickwork or into a raglet in stonework, the edges should be left and a flushing added. This flushing is a narrow strip of tin, zinc, or cop per secured along- one side in the joints or raglet, the other end being bent over the upturned edge of the gutter metal, which it should overlap about 4 inches. By this means one edge of each piece of metal is left free for expansion and contraction. The apron, or overhanging piece, is secured by being burned in or run into the groove in the top of the blocking course, the metal being filially- caulked or punched into the groove.
Roof gutters are now frequently- made of cast-iron pipes, generally of either half-round or ogee section, and iu lengths of 6 feet, the half-round pipes being from 3 inches to 6 inches in bore, and the ogee from 3;4 to 6 inches. Lead, formerly used extensively for roof gutters, has been siiper seded by other metals, as it is liable to perforation by vermin, nails, or corrosion.
Rain-pipes or conductors (fig. 17) descend vertically, and are composed usually of cylindrical sections of tinned or galvanized iron of suitable diameter for their intended service, joined together, and secured at dis tances of about 6 feet apart by- collars or soldered to flat straps fastened to the wall. They are fitted with large case heads above, to receive the water from the roof gutter, and with shoes below, to eject it in the required direction. Rain-pipes of corrugated sheet metal "have lately come into very- general use in the United States. They have the advantage of being free from liability to bursting from the freezing of water within them, the corrugated form permitting of an increase of sectional area (pi. 2, fig. IT).