Roofs for Farm- Buildings. 



119 



feet (10 feet x 10 feet) of the various roofing materials referred 

 to, with the relative cost of each : — 



These several prices, as well as the prices of timber, which 

 will be subsequently given, are quoted as a datum or standard 

 for the cost of roofs, worked out in detail hereafter, sinijdy for 

 the jmrpose of comparison, and they are based upon the assumption 

 that the best materials and workmanship will be employed. 

 They must be accepted with the general reservation, that they 

 will vary Avith the market prices of different localities, which 

 will sometimes be lower or perhaps higher than the prices 

 quoted. 



The effective value of different materials used for covering 

 will vary ; each is found to possess some counteracting quality : 

 thus straw, which best preserves an equable temperature beneath, 

 is a wasteful and perishable material for thatch, deprives the 

 farmer of the more legitimate application of straw as fodder 

 and manure, and should, therefore, be discarded from further 

 consideration. Tiles, both plain and pantiles, preserve an 

 excellent temperature beneath them, and, particularly so, when 

 laid upon straw or reed. A preference will be given to plain 

 tiles over pan tiles, because the latter, although somewhat cheaper, 

 are apt to be blown off, and, under general circumstances, pre- 

 sent a less pleasing appearance. Plain tiles, on the contrary, 

 have a decidedly neat appearance and agreeable colour, but 

 they are heavy, comparatively with slate, and require to be laid 

 to a higher pitch. 



Slates are economical, because, as just stated, they admit of 

 a reduced pitch, and are very durable, but they are quick con- 

 ductors of heat and cold, unless laid on boards, when they 

 become a very superior, though expensive covering. 



Iron covering, consisting of rolled sheet iron, is a ready con- 

 ductor of heat and cold, and, therefore, must be laid on boards, 

 when it forms an expensive covering. This fact, in conjunction 

 with its readiness to corrode, renders sheet iron, though galva- 

 nised, inapplicable to farm-buildings* 



