Ponding of rainwater is a special load case that can lead to roof collapse.
Ponding on roof plan.
Those pitched roofs have a natural slope where the water can run down draining off the roof.
Materials such as the roofing material vents and their location and the type of underlayment are also typically specified on the roof plan as seen in figure 20 3.
This type of occurrence is called ponding water and typically occurs due to the settling of a building which creates an unlevel surface.
On shingle roofs most building codes require a minimum slope of 4 12 with an underlayment of one layer of 15 pound roofing felt.
Ponding water is known in the roofing community as water that stands in a puddle on the roof for more than 48 hours at a time.
So if your flat roof is collecting water that doesn t drain or evaporate within 48 hours you will need to fix it.
Flat roofs by their very nature will collect some water when it rains.
Because these roofs don t drain water that well they are prone to developing what is known as ponding water.
Ponding is the unwanted pooling of water typically on a flat roof or roadway.
On low slope asphalt roofs ponding water allows the oil solvent components of the asphalt to leach out and evaporate leaving the roof membrane brittle and susceptible to cracking and leaking in the ponding location.
To specifically define the terms ponding or standing water refers to when water has not drained off the roof and has formed puddles or ponds 48 hours following the reason for the water.
As the angle of the roof is increased the size of the overhang may need to be decreased so that the eave will not extend into the line of sight from the window.
Raffles place mrt sees water leaking from roof on north south line platform.
Many homeowners now prefer using silicon coating for their flat roofs because of its appealing aesthetics and solid protection from leaks.
When the water is unable to drain it accrues in little ponds in the low points of the roof.
If the water does not drain within a 48 hour period it is highly likely that it will stay even longer and there will be a larger amount of water standing.
However excessive ponding threatens your roof.
Roof plans are typically drawn at a scale smaller than the scale used for the floor plan.
A scale of 1 8 1 0.
In the dutch code for loadings and deformations nen6702 1 and.
In dutch building practice the most frequently occurring damage cases are failures of flat roof structures caused by ponding of rainwater.
On many commercial flat roofs water doesn t properly drain off of the building.
If there is ponding water on your flat roof it may also affect adhesion.
Ponding water accelerates the deterioration of many materials including seam adhesives in single ply roof systems steel equipment supports and particularly roofing asphalt.
It may also void your warranty.
How to fix ponding on a flat roof depends on the cause of the ponding.
Roof plans a roof plan is used to show the shape of the roof.
