Tool Category Building Materials

Architrave and casings are measured per opening and bought by the length, which means two different units meet in the middle and the waste happens where they meet. A door needs roughly five metres of architrave — two legs and…

Roof pitch is quoted three different ways and the three are not interchangeable in conversation. Trades in some places say a ratio — four in twelve — meaning four units of rise for twelve of horizontal run. Architects say degrees.…

A stair is two dimensions that have to agree. The total rise is fixed by the building — floor to floor — and dividing it by a comfortable riser gives the number of steps, always rounded up to a whole…

Insulating a wall is two decisions wearing one coat. The first is how much area you are covering, which decides how many boards you buy. The second is how thick they are, which decides what the wall ends up performing…

A stud wall is set out at centres, and the count is the wall length divided by the spacing plus one — which is the part people get wrong in both directions. Then come the openings, which need studs on…

Tile adhesive is sold by weight and used by area, and the rate is set almost entirely by the trowel: the notched edge leaves ridges of a certain height, and the height of those ridges is how much adhesive stays…

A brick wall is mostly brick. The mortar is the difference between the volume of the wall and the volume of the bricks in it, which sounds like a subtraction and is — but the subtraction undercounts, because bricks have…

Skirting looks like the simplest measurement in a room: go round the walls, subtract the doors, buy that many metres. It is nearly that simple, and the parts that make it not simple are worth knowing before ordering. Every length…