THE roof of a building is intended to cover it, and to keep out the weather.

There are many different ways of arranging the timbers of a roof, which vary according to the span, the requirements of the building, the climate, and the nature and weight of the covering to be used.

This course extends only to a consideration of one or two of the most ordinary forms for roofs for small span, and terminates with a description of the " King-post Roof."

It will be well to trace the gradual development of the Kingpost Roof before describing it in detail.

N.B. In all the figures illustrating this section, the parts are marked with the distinctive letters mentioned below.

Battens ..

b

Binders ..

Bi

Blocking Course

BC

Boarding ..

B

Ceiling Joists

cj

Cleats...

cl

Collar Beam ..

CT

Cornice ..

C

Corbel...

c

Fascia ...

/

Gutter...

9

Gutter-bearer ..

gb

Gutter-plate ..

9P

King Bolt ..

KB

,, Post ..

KP

„ Tie ..

KT

Parapet "Wall

PW

Pole Plate ..

PP

Purlin ..

P

Rafters, Principal

PR

,, Common

CR

Ridge ...

r

Slates ...

s

Soffit...

fs

Struts ..

s

Templates (wall)

wt

Tie Beam ..

T

Tilting Fillet

if

,, Batten

tb

Truss, Principal .

TP

Wall Plates

wp