In estimating sheeting for shingle roofs make no allowance for spreading the boards. Calculate the same as for close sheeting a roof, for what is gained in spreading the boards is generally lost in the cutting. The boards should never be placed more than 2 inches apart for a good roof. Sheeting for gutters on roofs having box cornices is an item often forgotten. These gutters are variously formed, but usually consist of four pieces of sheeting, forming a bottom, two sides and a fillet next to the crown molding. The combined width of these pieces is from 1 to 2 feet. Hence the amount of lumber required for gutters may be found by multiplying the length of the gutters by the combined width of the pieces which form it.
For example, suppose the length of gutters on a building is 42 feet, and to form the bottom, sides and fillet requires a board equal to 1½ feet wide, how much lumber will be required ? Operation: 4.2 x 1½ = 63 feet.
The sheeting for gutters often amounts to several hundred feet on large jobs, and is a matter worthy of attention. Sheeting is one of the items of which carpenters usually fall short. The reason is obvious, it being one of the cheapest kinds of material. It is used for many purposes for which the carpenter does not count. Wherever a board is wanted for one purpose or another, a sheeting board is taken, provided it will answer, while several hundred feet are usually employed in building scaffolds. A large portion of this is wasted by being nailed, sawed and split, It is safe to say that in estimating sheeting one-fifth should be added to the net estimate.