Tasaand other guide lines of good practices of thatching house hold entities indicate a time period and rationale table for when roofs are to be over thatched or add an additional one.
Thatch roof thickness.
22 nov 2012 in general re thatching tagged re thatch re thatching thatch thickness by peter brugge when the time comes for a re thatch many thatch owners are amazed at the new thatch thickness and also how new looking the old thatch still is just below the surface where the weather has not penetrated.
The minimum thickness of the new coating shall be 10 inches and this shall be regarded as the standard specification for recoating work.
Over a period of time the roofs will become very thick because the thatcher will not strip much of the old thatch away.
Thatched roofs generally need replacement when the horizontal wooden sways and hair pin spars also known as gads twisted hazel staples that fix each course become visible near the surface.
The surface shall conform to the pitch of the roof and hollow areas thatched out.
Thatch thickness has always been a sensitive subject among contractors and thatch owners and some miss conceptions were able to take foothold over time.
The amount of thatch below the fixing can vary this being determined by the length of material and any backfilling giving an overall thickness of anything between 9 and 15 inches 225 375mm to a thatch roof.
Generally straw roofs have multiple layers of thatch and many thatchers will secure the new coat to the one below using twisted hazel fixings.
The thickness of a layer of thatch decreases over time as the surface gradually turns to compost and is blown off the roof by wind and rain.