This section is from the book "Spons' Mechanics' Own Book: A Manual For Handicraftsmen And Amateurs", by Edward Spon. Also available from Amazon: Spons' Mechanics' Own Book.
This is only 5 ft. high at the eaves, and 10 ft. at the apex. It consists simply of fixed rafters mortised into a ridge-board at top, and an eave-board at bottom.
The width of the ridge-board a depends upon that of the sashbars; 2 in. will be thick enough for the house treated of. b represents the beading fastened by screws or nails to the top of the ridge-board, to preserve it from the action of the weather, as well as to impart finish to building, a also shows how the sashbars are mortised into the ridge-board, and how a groove c for the glass is ploughed in the ridge-board above each tenon. In glazing, especial care must be taken to thrust the glass to the top of these grooves, so as to make the ridge weather-proof. The size of the sashbars is determined by their length, and whether it is intended to strengthen the roof with stays, or pillars with supports, as shown in d. A bar of the form shown by d, 2 1/8 in. by 7/8 in. at its widest part, answers very well, with every fifth bar like the section e, in size 3 3/4 in. by 2 in. When interior supports are not used, the bars should be 3 in. by 1 1/4 in. with every eighth bar 3 1/2 in. by 3 in. The eave-board f should be 4 in. by 2 in., bevelled as shown, and with a small semi-circular groove to prevent any moisture creeping into the house, under the eaves, as will happen without the groove.
In exposed windy situations, additional strength may readily be imparted by bolting a few iron braces to the angles of the building at any convenient point, as shown by g. Pieces of bar iron bent to the required angle, flattened, and holes pierced at the ends by a blacksmith, answer admirably, and are neat enough in appearance when painted. To those who prefer the usual plan of side pillars, h will be useful, as showing a longitudinal sectional portion of such a pillar, with a slot cast in the top to admit a flat iron bar on edge, running along under the roof from end to end, and forming a capital support, so light as to make no appreciable shade, and yet very strong; in size it is 3 in. by 1/2 in. The brackets for hanging shelves i are objectionable, as spoiling the appearance of the interior; but such shelves are so useful that they are shown where to be placed, for the guidance of those who are compelled to use them. The roof support shown is considered by Luckhurst preferable to the ordinary style. It consists of central pillars k, with arms 1, the pillars being placed about 9 ft. apart.
The hanging baskets m are suspended by chains with counterpoise weights, which enables them to be lowered at will for watering and inspection.