Material comparisons

9 matrices. Each one names a pick and says why, then shows the rows the pick was made on — installed cost, service life, dead load, warranty and repairability.

Every price row reads from the same national cost tables as the calculators and the guides, so a figure on a matrix never disagrees with the page it links to. Use a comparison when you are choosing between two things; use the matching calculator once you have chosen, to price it on your own roof.