Here is a quick example of how GM Home Improvements would estimate for a new roof, We will use a basic terrace house as an example. Firstly we calculate the square meterage, this can be done exactly by measurement from the top of a ladder, or from the floor if a quick ‘guestimate’ is required.
Square metres of a roof – All roofs break down into a series of manageable chunks where the amount of tiles required can be worked out from the final square metre figure.
Now we know we require 55m2 of tiles to tile the roof including a 3m2 allowance for breakages. Using Redland 49 tiles at the correct overlaps, it works out to 15.7 tiles per square metre X the 55m2 we require, which means that 864 roof tiles are needed to tile this roof.
Any roofing supplier will tell you the amount of roof tiles and batten for a given tile if asked, as long as you supply them with an accurate m2 figure.