Tag: Waterproofing

Posted on

Roof Crocodiling or Alligatoring

WHAT IS ROOF CROCODILING AND HOW DOES IT AFFECT YOUR FLAT ROOF?

flat roof crocodiling of waterproofing
Flat roof waterproofing looks like crocodile skin. This is crocodiling!

Waterproofed concrete and composite flat roofs on residential and commercial buildings require more maintenance than sloped roofs. They react differently to sun and moisture than tiled or sheeted roofs and require more frequent maintenance to ensure they function as they should. One common problem with many flat roofs is crocodiling.

What is Crocodiling?

Crocodiling is a crazed cracking pattern on the surface of the waterproofing. It looks like crocodile skin, which is where the name comes from.

Crocodiling is a sign that your waterproofing is ageing. The sun’s UV rays dry out and damage the waterproofed surface, and after five years or more years, the coating may develop small cracks. The older your roof gets before you repair the crocodiling, the more expensive it will get.

Extreme temperature changes, changing from hot sunshine to sudden cloudbursts and rain, and even hot winter days and very cold nighttime temperatures will cause new cracks to appear and will make existing cracks worse. 

Leaves and debris will allow water to pool on the membrane which, together with the elements, will hasten the deterioration of the protective coating and waterproofing itself.

Continue reading “Roof Crocodiling or Alligatoring”
Posted on

Cracks and how to handle them

Don’t Panic when your house cracks!

crack defects in the foundation footings and walls
Changing moisture conditions under your house can cause defects in foundation footings and walls

Most homes develop defects such as cracks. Old and new homes can develop cracks in foundation footings and walls caused by climatic and physical factors.

However, it is worth getting to the bottom of what is causing the defect. A crack is the visible symptom of a possible problem or defect causing the crack.

What causes cracks?

New homes

In new homes, settlement may cause minor cracks. Normal foundation settlement occurs when the underlying soil compacts because of construction on previously undisturbed soil, changes in soil conditions and moisture. Typically small, hairline-sized cracks may indicate a minor settlement, expansion and contraction, or changes in a season or cycle.

Usually, these defects, though often unsightly, are not structurally significant.

Thermal movements between different materials

Different materials such as timber, bricks, steel, concrete etc. have different linear expansion coefficients. In other words, the differing materials contract and expand differently. This causes stresses in structures where they are combined and may cause cracking to form. The best way to combat these defects in plasterwork is to provide a joint between the different materials.

Older homes

In older homes, changes in climatic conditions can affect the structure. Houses move with the climate. Heat and moisture will make them expand, and cold and dryness will make them contract slightly. This movement is normal and in most cases will not cause cracking. Unusually hot or cold spells can increase the structural expansion or contraction which may cause cracks.

The rise or fall of the water table in very dry or wet conditions can also affect the house’s foundation footings.

Continue reading “Cracks and how to handle them”
Cookie Policy (ZA) Proudly powered by WordPress
error: Content is protected !!