Читать книгу Harper's Outdoor Book for Boys - Joseph H. Adams - Страница 26

A back-yard pergola is constructed from two upright posts four inches square, a cross beam two by six inches, and eight joists laid across from the post bar to the top of the back fence. This style of pergola is particularly adapted to city yards and those surrounded by a board fence. In the event of there being no fence, the ends of the joist or roofing beams may bear on a two-by-six-inch cross bar that rests on two more posts corresponding with the front ones.

The posts are four inches square, of spruce or any other available wood, and are planed on all four sides. They are embedded in the ground for about two feet, and, to prevent them from sinking or shifting, place a large, flat stone in the hole on which the post will rest, and around it pack earth and stones instead of earth only. A lap cut in the front top end of the post will admit the two-by-six-inch cross beam. The posts are seven feet apart, and the cross beam ten feet long, with the ends cut as shown in Fig. 3 on page 56. The front end of each joist is rounded under as shown, and to make a more secure anchorage a notch two inches long and an inch deep may be cut at the under side of each joist, so that they will fit down over the upper edge of the cross beam. Make all the joints and laps fast with steel wire nails; then give the wood-work a few coats of paint.

Seats may be built in on two sides and supported with under braces or brackets to prop up the front edge, and a back-board may be nailed fast to the posts and fence.