WOOD-ANDIRON BUILDINGS 



'87 



£ inch apart by a number of hardwood washers of that thickness, and 

 6£ inches square. Each pillar is firmly anchored by being bolted to 

 a 5-foot length of 7" by 4" rolled steel joist, bedded 2 feet in a heavy 

 concrete foundation block, as shown and dimensioned in Fig. 90. 



The roof trusses are of the cross-braced type illustrated by Fig. 53, 

 the rafters being 9" by 1£", and the cross-braces 6" by 1£". The roof 

 covering is of corrugated iron. It will be noticed that 6" by 3" roof- 

 plates are used, set on edge, and checked into the tops of the pillars. 

 These roof-plates are supported by 6" by 3" diagonal struts at the 

 head of each pillar. Below the roof a curtain of corrugated iron is 

 fixed, its lower edge being 11 feet above the ground. The lower part 

 of the curtain is nailed to a 6" by 3" rail, inserted between the pillars 

 and supported from the roof-plate, halfway between the pillars, by a 

 £-inch suspension bolt. This curtain not only protects the forage 

 from the weather, but also strengthens the barn against distortion due 

 to wind pressure. 



The barn is capable of being extended indefinitely, by adding new 

 bays similar to that shown in Fig. 89. 



Each additional bay is placed alongside the existing bay or bays, 

 the roof-ridges of all the bays being parallel to each other, and 

 the pillars between 

 adjacent bays being 

 common to both. 



The manner in 

 which the valley, be- 

 tween the roof 

 slopes of adjoining 

 bays, is formed is 

 illustrated by Fig. 91. 

 The ends of the 

 rafters are crossed, 

 above the roof-plate, 

 and 2" by 3" bearers 

 are nailed across them as shown. These bearers carry 1^-inch planking 

 on which is supported the bottom of the valley gutter, formed from 

 plain galvanised iron sheets. The sides of the valley gutter are sup- 

 ported on the thinner planking shown, which is nailed to the lowest 

 purlin of each roof slope, and to the bottom planking. 



Fig. 91. 



