Waste pipe:

A drainage pipe conducting waste water from a bathroom, kitchen sink or washing appliance.

Water-tabling:

A traditional term for a course of stone projecting out beyond the face of a chimney stack to throw water off.

Weather mould (or drip mould):

A moulded section of timber fixed across the base of a door, or above a window or door frame, to throw off water from the face of the door or window.

Weatherboarding (or shiplap boarding):

Overlapped timber boarding, usually hardwood, providing an external cladding.

Wet rot:

A fugal decay commonly affecting external timbers which have not been kept well painted or otherwise maintained, whereby the timber becomes soft.

Woodworm:

The general term given to infestation by certain wood-boring insects such as the common furniture beetle.