Tata Durashine colours and sizes

Durashine's ten standard colours are Asian White, Cool Blue, Nuvo Blue, Bright Green, Pearl Green, Castle Red, Passion Red, Cherry Red, Coffee Brown and Smart Grey. Three of the ten are reds and two each are blues and greens, so saying red on the phone still leaves three sheets it could mean; the published name is what fixes a shade. The maker's own FAQ prints the grey as Graphite Grey where its leaflet says Smart Grey, so for a grey roof, ask for grey and settle the exact shade off the card.

Every colour is published as subject to local availability, in the maker's own words, and the leaflet adds that its printed shades are for reference only and the actual product colour may vary. So a shade is never fixed off a phone screen or a printout: it is read off a standing sheet or the shade card at the counter, and because ridge, flashing and the other accessories are published in the same colours as the sheets, the trim can be matched to the roof in the same breath.

Overall width and effective cover are two numbers on the same sheet. A Durashine roof sheet measures 1072 mm edge to edge but adds only 1015 mm to the roof, because one rib rides over the next sheet's edge. Divide the width of one slope by 1.015 metres and round up, and that is its sheet count. The wall profile covers more, 1110 mm, on a much shallower rib, 11.6 mm deep against the roof profile's 28.5 mm, and that rib depth is most of what makes a roof sheet a roof sheet.

Two more of the maker's figures belong on the drawing. The minimum roof slope Durashine publishes is 5 degrees, so a nearly flat lean-to sits below what the sheet is made for. And the steel is zinc aluminium alloy coated with a minimum yield strength of 550 MPa, which in plain words means a harder steel, made to take a heavier pull before it gives. How far one sheet laps the next along the slope is worked through on the sheet length and overlap guide, and the whole colour sheet rack, other brands beside Durashine, is on the colour chadra page.

CoolShield, the insulated Durashine sheet, is published in the same four painted thicknesses and in lengths from 8 to 24 ft, built as painted steel over a 5 mm XLPE insulation layer with an aluminium foil face beneath. The shade for an insulated roof is settled on the call, the same way its length is. What the sheet is and the jobs it goes on are on the CoolShield page.

The curved sheet, printed LongLine Crimp by the maker, is published in two typical curves, 273 mm and 469 mm, both subject to local availability, with a made-to-measure curve past those two. Curve, colour and length travel together on a crimp order; the rest sits on the crimped sheet page.