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.
If you are like many homeowners, you have probably wondered why some houses have no gutters to provide protection against stormwater. You may have wished your own home had none because of the cleaning and maintenance issues.
Gutters are not required by law on a sloping roof. Many modern homes have none, even in instances where they would benefit by having them. There are alternatives that architects sometimes prefer such as concrete paving around the perimeter of your house.
In order to decide for yourself whether rainwater gutters are necessary for your home, it is best to first learn what the building regulations require.
The Building Regulations do not require roof gutters and downpipes if another suitable means of drainage has been provided to remove or disperse rainwater from the roof away from your home.
However, the Building Regulations do require that any stormwater that flows from your roof or any area that is in the immediate vicinity of your home must not cause damage to theinterior of the building, its structure or its structural elements. The regulations require steps to be taken to ensure that stormwater does not accumulate in a way that“unduly inconveniences” you as the occupant of your home.
Furthermore, the system used must:
not undercut the foundations by erosion or flooding
drain stormwater away from your home
not allow stormwater to accumulate against or close to the external walls
make provision for the drainage of any areas on the property where water pools
Spring has arrived at last! However, you should have inspected and maintained your gutters and roof by the end of winter. But, if you haven’t, you better do so now! They may be clogged with leaves, debris and dust.
Gather up your ladder, a plastic bag, your hosepipe and get busy. If you don’t, the timbers supporting your gutters may soon look like this!
If your roof does not have gutters installed, the roof structure probably has damage to the feet of the roof trusses. Check under the eaves of the roof for moisture damage before it’s too late.
Consider installing gutters before the roof timbers rot and fail. If they have rotted the repairs will be extensive and expensive!
Check your roof and gutters
Cut back trees and branches that deposit leaves and dead wood on the roof. Remove any debris from your roof. If you can’t do it yourself, hire a good roofing contractor to get the job done. This should be a priority. Debris prevent the free flow of rainwater off the roof! Roof tiling and roof sheeting are not 100% waterproof. These roofs are water-shedding systems rather than waterproofing systems.
Check your tiled roof while you’re up cleaning your gutters! Check for broken or cracked roof tiles, dislodged tiles and cracked mortar on the ridges and hips.
Foot traffic easily damages the tiles on your roof. If you walk on your tiled roof you will probably cause some damage. Also, consider the safety aspect! A fall from your roof can result in serious injuries and even death. Roofing specialists should repair any defective or broken tiling
Moisture absorbed into brickwork and plasterwork causes them to expand slightly. When the brickwork and plasterwork dry they contract slightly. The water absorbed by the bricks and plasterwork usually causes a slight vertical crack at the edges of the internal window sills. The paint then starts to bubble along the vertical crack. This crack may continue around the length of the window sill before you notice it. What started out as a small vertical crack then becomes a horizontal crack along the bottom of the window sill on the interior face of the sill wall.
The cracks are usually not significant unless allowed to continue unabated.
Sometimes the moisture intrusion at sills are mistaken for rising damp! Water leaking in at the window sill may bypass the damp proof course (DPC) built in under the window sill as a water-resistant barrier. The moisture may then appear as bubbling paint or crazing cracking of plasterwork, or both, below the window, extending down to floor level.
On external face-brick walls, this may appear as efflorescence (a white powder).
Internally, this may appear as bubbling paint above the skirting or discolouration of the skirting itself.
How do you prevent the moisture intrusion into window sills?
Maintain your home, especially the roof, on an annual basis. If you don’t do the small repairs they could end up as expensive repairs.
Your roof is the most important component of your home, protecting you, your belongings and the structure of the building. Damage to the roof can occur due to rain, wind and hail. You should regularly check the roof of your home for any leaks. Also inspect the ceiling, walls and the area around your home for any water spots, standing water or mould. Dampness on ceilings or walls can mean that there are leaks that you will have to attend to.
Check the chimney
Loose flashings, damaged masonry and loose bricks will allow rainwater in a house. Be sure to give the area around the chimney an inspection to ensure everything is fine. Refit loose flashing or replaced as necessary. Furthermore, chisel out the damaged mortar joints and rejoint, and also repair loose bricks.
Loose, dislodged or broken roof tiles or ridge caps
If you have the ladder long enough, inspect the roof for loose or crumbling mortar along the ridge cap. At the same time, check for cracked or damaged roof tiles while you’re up there. However, if you do discover problems and can’t deal with it yourself, call in a professional roofing contractor.Continue reading “Winter Home Maintenance”