WHAT IS ROOF CROCODILING AND HOW DOES IT AFFECT YOUR FLAT ROOF?
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 in 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 protective coating and waterproofing itself.
Most homes develop some cracks. Old and new homes can develop cracks as well depending on climatic and physical factors.
However, it is worth getting to the bottom of what is causing the cracking. A crack is actually the visible symptom of a possible problem and not the problem in itself.
What causes cracks?
In new homes, settlement may cause minor cracks. Normal foundation settlement occurs when the underlying soil compacts as a result of construction on previously undisturbed soil, changes in soil conditions and moisture. Typically small, hairline-sized cracking may be the result of the 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 coefficients of linear expansion. In other words, the differing materials contract and expand differently. This causes stresses in structures where they are combined and may cause cracks to form. The best way to combat these defects in plasterwork is to provide a joint between the different materials.
In older homes, changes in climatic conditions can affect the structure. Houses move with the climate. Heat and moisture will make them expand, 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 result in increased expansion or contraction of the structure which may cause cracks.
Any structure requires ongoing roof inspection and roof maintenance to prevent leaks. By identifying minor problems you can save yourself major repair costs in future. You can thereby also extend the lifespan of your roof considerably before needing to replace it.
Types of Roofs
Together with walls and windows, roofs are a primary component which protects the interior of the building.
There are two main types of roof systems: low-slope (flat) and steep-slope roofs.
Most multi-unit residential buildings use low-slope roofing, while townhouse buildings and single detached houses generally use steep-slope roofing.
Both roof types may be used in some buildings.
Low-slope roofs have a waterproof membrane and a series of drains that remove water from the roof surface. As they are low-slope, these roofs must be water-tight to function properly.
The roofing membrane is applied as;
A liquid that cures or dries to form a waterproof surface,
Or fabricated from pre-manufactured sheets, joined together to create a surface, impermeable to water.
These membranes seal all openings and penetrations through the roof to prevent water leaks. With frequent roof inspections and maintenance, the membranes can provide a leak-proof for up to 20 years.
Steep-slope roofs have overlapping roofing materials to create a surface that, together with gravity, sheds water effectively. The roofing materials include:
asphalt or fibreglass shingles,
and asbestos/fibre or metal sheeting.
Why roof maintenance?
Reduce the likelihood of premature leaks and ageing by regularly inspecting your roof, and doing maintenance work where necessary. Sunlight, rain, hail, wind and temperature changes gradually break down the roofing materials. Eventually, the roof will need to be replaced. However, proper maintenance and care will maximize the service life of the roof.
Roofing systems generally have an anticipated “leak-free life”. The roof should not leak over this time span if properly designed, constructed and maintained. After this time the roof system may still continue to provide many years of service. Leaks will, however, occur eventually. These may increase up to a point when the entire roof will need to be replaced.
After a severe windstorm, or extreme weather, inspect your roof for damage.
Proper roof maintenance reduces costly premature damage. Undetected leaks can damage the building’s structure and interior finishes.
Roof inspection, maintenance and repairs
All roofs require regular inspection. Because of safety issues, a professional home inspector or professional roof inspector should be employed for this purpose. A professional inspector has specialist knowledge, uses the proper equipment and meets all safety requirements. You, your body corporate or maintenance manager should coordinate this work.
A possible roof problem can be identified by damage to the ceilings or walls of the home. If you are renting or living in a complex, notify your body corporate or maintenance manager.
The qualified professional inspecting the roof should
be familiar with the roofing system in your building,
be able to identify potential problems, and
know how to take the necessary safety precautions while doing an inspection or maintenance work.
Specific items for roof inspection and maintenance will depend on the type of roof(s) on your building. You will find a checklist of common roof maintenance items at the end of this article.
Inspect twice a year;
in the autumn or spring to address any possible summer or winter damage, and
In the spring or autumn to prepare for the upcoming summer or winter rain.
After any storm, high winds, extreme rain or hail, inspect your roof, including flashings and other accessories. If construction has taken place on the roof, check for leaks.
The roof inspection should include the underside of the roof structure and the outside of the building. These areas may show up potential problems with your roof.
Who does the roof inspection?
Hire an InterNACHI certified home inspector to inspect and review the condition of the roof.
A professional roof contractor should carry out any required roof maintenance. The professional will have the necessary tools and knowledge to repair identified the problems. Skylights and other roof penetrations may require specialized attention. A specialist supplier or manufacturer may need to be employed.
Weathering reduces the expected service life of the roof. Furthermore, it also affects the appearance of the roof. A yellow or brown stain on the ceiling could be an indication that moisture is leaking from the roof.
Roof leaks can result from overflowing gutters or backed-up downpipes. Debris in gutters and downpipes can prevent proper water drainage. Moreover, this may also result in water backing up and overflowing into adjacent building walls and moisture damage to the roof structure.
This makes periodic roof inspections essential!
I will do a RoofInspection and Report which will identify problems with your roof. The report will include the condition of the roofing products, materials and flashings. Furthermore, the report will also include any other roof maintenance issues.
My Comprehensive, Snag (New Home) and Maintenance Inspections include all of the above. Also included is the stand condition, property boundary and courtyard walls, swimming pools, garages, decks and so on. To clarify, an itemised list is provided below.
Your home inspection
Firstly, I am a trained and skilled InterNACHI Certified Home Inspector. Therefore, you will receive a thorough and professional, non-intrusive, visual home inspection and report of the property.
Moreover, I inspect the property you wish me to report on, inside and out, from the boundary walls to the top of the roof. Following that, I draw up a detailed comprehensive report of all the components inspected.
Outside the home, I will inspect the property boundary walls, the garden, the building’s walls and roof, driveway, deck etc. Moreover, if you request it I will inspect your swimming pool. Then I will move inside to inspect the walls, ceilings, floors, doors, and windows. In addition, I also inspect the heating, air-conditioning, plumbing, and electrical systems to ensure that they work as intended. Likewise, bathrooms, kitchens, and laundry rooms also receive a thorough check. Following on, I will check the roof (ceiling) space and basement, if any.
that, I will prepare a detailed home inspection report of all the items
inspected, including photographs. Furthermore, the report will be clear and
easy to read.
Moreover, as The Home Detective, I strive to ensure my home inspectionservices and reports are the best. I value customer service above everything else.
Air Conditioning systems
Cupboards and kitchen tops and units
Damp in walls, floors and ceilings
Decks (all types)
Electrical boards & components (DB, plugs, light switches and lights)
External finishes (faced, plastered and timber and steel framed)