J36 F A R M B U I L D I N G S. 6. 



To remedy thefe two evils, it has of late 

 years been the common pradtice to *' fheet" 

 the roof; that is, to interlath with plaftering 

 laths between the tiling-laths, and cover the 

 entire roof with a Iheet of lime mortar : and 

 over this, to lay the tiles on " dryj" that is, 

 without bedding or pointing them, being 

 careful not to fuftcr any part of them to 

 touch the mortar : — to prevent which a flip 

 was nailed in between the fpars and the 

 tiling-laths to raife the tiles fufficiently abpve 

 the flieeting. 



This method, which has been praftifcd 

 fome fifteen or twenty years, has been found 

 cfFedtual againft the two inconveniencies 

 above mentioned ; but it has lately been 

 found, that in twelve or fifteen years the 

 laths begin to fail, owing it is fuppofcd to 

 their being expoled too near to the outward 

 air ; from which the lime alternately ab- 

 forbing and imparting moifture, the laths be- 

 come fubjcfted to decay. I am rather of 

 opinion, however, that this efxed is caufed by 

 the tiling-laths; whofe under-fides touching 

 the plaftcring, check the dcfccnt of the rain 



or 



