Technical Terms

Basics in Building Construction 4(2+2)

Lesson 05 : Damp Proofing Treatments

Technical Terms

Some of the terms used in damp proofing are explained below.

Sweating: The process by which humidity from the air will condense upon any surface below dewpoint temperature such as window-panes or walls.

Condensation: The transformation of vapour into liquid because the temperature drops below a given level, specific to each liquid.

Surface Condensation: The condensation of liquid on cold glass or when damp air comes into contact with surfaces below the dewpoint, i.e. the temperature at which the air becomes saturated.

Damp Course: A horizontal layer of a watertight material, such as dense limestone or metal, laid upon the lower course of a masonry wall to prevent damp ascending through the brickwork by capillary action. Also called damp check or damp proof course.

Vapour Retarder: A membrane covering the outside of the insulation around a cold water pipe to prevent the damp from soaking the insulation and reaching the pipe. Also called vapour barrier.

Pargeting: A thin layer of mortar with added dampproofing ingredients applied on the outside of masonry walls of basements, near the foundations, below grade. Also called pargework or parging.

Roofing Felt: A waterproofing material consisting in asphalt saturated felt sheet, dressed with another more resistant layer of asphalt with mineral fibers or organic stabilizers; the side exposed may bre coated with aluminum sheet or other solar protection. Also called as asphalt prepared roofing.

Protected membrane roof: A waterproof membrane that also provides insulation from extreme temperatures by means of a rigid insulation board coated by a layer of gravel.

Compression Gasket: A strip molding of extruded synthetic rubber designed to be fixed to a window – frame; firmly compressed by the pane of glass, to create a waterproof seal.

Joint Sealant: Material designed to fill the joints in a building so as to create, when dry or curved , a flexible weatherproofing seal.

Last modified: Wednesday, 29 February 2012, 7:09 AM