Many industrial and commercial buildings have flat roofs, and this can cause significant problems in terms of drainage. Flat roofs with poor drainage can lead to an issue known as “ponding” when there is heavy rainfall. Ponding is when water collects on a roof and does not drain away, and this can cause severe issues for the roof.
Flat roofs require unique drainage solutions to help prevent ponding. Here’s a look at why roof drainage is essential, what can cause inadequate drainage as well as how to improve drainage.
The Importance of Good Drainage
Good drainage is vital for any roof as standing water can cause serious damage. Ponding can create a permanently damp environment which is perfect for moss growth, and wet moss can make a roof dangerously slippery, which could be seriously hazardous if you regularly access your roof. Additionally, if the water freezes this could also create a safety hazard, not to mention the ice will cause unnecessary stress to the roof’s structure.
Damage to the structure of a roof is possibly the most significant issue with inadequate drainage. Standing water can eventually split the roof, which can cause leaks into the property. As the roof struggles to cope with the additional weight, it may collapse altogether, which will be incredibly expensive and difficult to fix.
What Can Cause Inadequate Drainage?
Debris in Gutters
Gutters can become easily clogged with debris such as leaves and sludge. When drains are blocked from working, water has a chance to stagnate on roofs, and not just flat ones either.
Flat roofs still require some level of slope to deliver the rainwater into the drainage system effectively. Poor roof construction that leads to uneven slopes can result in the water becoming trapped in the roof and unable to reach the drainage system.
Sagging roof deck
A sagging roof deck can prevent a roof from having an even slope, meaning that the water is unable to drain away efficiently.
Lack of Drains
A lack of drains can also cause inadequate drainage, and more may need to be added to your roof if you’re finding that you’re having problems with stagnating water.
How to Improve Drainage on Roofs
Preventative maintenance should be done to ensure that you manage to catch any ponding issues early before it can cause damage to your roof. It’s a good idea to check the roof after rainfall to see if there’s any sign of standing water. If there is any water, you should try to identify why it is not draining, such as checking the gutters for blockage.
The design of gutters means they are quite susceptible to becoming blocked. You should remove all accumulation of debris such as twigs, leaves and granules from the roof that have come from the shingles. To help prevent gutter blockage, keep trees trimmed away from the roof to prevent them from rubbing up against the roof and leaving leaves that will then accumulate in the gutters.
If the gutters are clear and there is still standing water, it could be a sign that the gutter is improperly sloped to the downspout. You can test for this by using a hose to spray water and check that it heads towards the rooftop and goes into the downspouts.
Inner drains can also be used to help with the drainage on flat roofs. They are usually placed near the centre of a building, and they attach to pipes that drain the water down through the building’s roof to keep the water away from the walls and foundation. They can, however, be costly to install and need to be severely maintained to prevent debris accumulation, as this can clog the system and create pools of water.
At Bushbury Cladding, we can provide you with roof sheets, metal roofing sheets and steel roofing sheets, as well as insulated wall cladding. Our specially designed sheets are available in a range of finishes and are made from the finest British steel. We also provide a wide range of accessories such as self-tapping Tek screws, nibbler drill attachments and Tek screw bit adapters to ensure you can complete your roofing sheet installation with no issues.
Contact us today to find out more about our wide range of products, and we would be happy to advise you.