waterproof balcony


As balconies are outdoor structures, they will always be subjected to the elements and therefore need specific preparation to make sure that they are waterproofed correctly. Although many balconies now are covered by a roof above or external cover, appropriate and thorough balcony waterproofing is still needed to make sure that no water damage comes through to the substrate. If this does occur, it can cause damage to the structure and in some cases to the property below. When constructing a balcony, it’s important that the following be put into place


Slightly sloped

Balconies should be built with a slight grade as to allow for adequate water drainage. To ensure that the gradient is sufficient there should be a minimum 1.5 cm gradient per meter area. If this minimum gradient is not adhered to, serious water damage can occur by water stagnating and not being able to roll away and drain properly.


Substrate preparation

As with all flooring projects the surface preparation is pivotal to the end result of the floor. The substrate must be clean, dry, and free from any dirt or debris. If a thorough clean is not performed and dirt or debris is present on the substrate the subsequent adhesion of flooring products will be affected and will result in a floor is that is loose or easily prone to damage.


Sealing joints, gaps, and pipes

If there are any external pipes and water fittings make sure that they are appropriately waterproofed and sealed so that leaks do not occur. These kinds of leaks can be more damaging than the natural elements as they are constant and often leaks can do unnoticed until there is a serious problem which by the time it reaches that stage can be very costly to repair.



Waterproofing of balconies is a very detailed process that must be done correctly so that no structural damage occurs in the balcony and building below. When waterproofing a balcony (or any area that has constant exposure to water) it’s always best and easiest to do the job to the highest standard from the start so that it doesn’t have to be redone later down the track. To waterproof a balcony correctly an appropriate waterproofing membrane must be applied. It can be beneficial to waterproof both above and below the screed to ensure the most thorough protection is being applied to the structure. Have a look at this blog post about waterproofing above or below screed here to learn more about this method of waterproofing.


Provisions for excess water

Sometimes due to heavy rainfall the excess water needs more channels to drain so it’s important that these drainage channels are built into the balcony structure. It is also important to make sure, especially on large balconies, that the drainage outlets are large enough and there is an adequate number of them. Flashing is also something that needs to be considered. Flashing is thin pieces of material that are installed to prevent water seeping through vertical or horizontal joints where the structure is more prone to water damage.


For further information on waterproofing balconies correctly, and which products will be suitable, please get in touch via phone or email, or send us a request via our contact us page.