Building Pathology Flashcards
What is damp?
A building or building element is considered damp when moisture becomes visible through staining, discolouration, sulphate attack, mould growth, frost damage or persistent visible surface moisture.
How can you test for damp?
Using a protimeter can help establish the presence of damp in buildings.
Moisture meters or a speedy carbite meter can be used to determine the moisture content of walls, and the level of damp.
What is a protimeter/ moisture meter
Protimeter’s work by measuring the electrical resistance between two applied electrons.
Protimeters are generally used to measure the moisture content of wood and when used on other materials the readings can be misleading, however this approach does give a sense of moisture content.
What is a speedy carbite?
a speedy carbite is a device that measures the moisture content of masonry.
By drilling into masonry and inserting the resulting dust into a sealed container with a known amount of calcium carbite allows the moisture content to be determined.
This works as the dust and calcium releases a gas in proportion to the amount of moisture content.
Describe the three causes of rising damp and the remedies?
Rising damp is caused either by a lack of a damp proof course, a defective damp proof course or external features bridging the damp proof course.
The remedy therefore involves removing the external feature causing bridging, the injection of water repellent chemicals into the brickwork or, the fitting of a new physical damp proof membrane.
Where a damp proof course is not suitable, lime plaster and wash can be used to minimise the damage caused to the internal finishes.
