Waterproofing your balcony

make your balcony waterproof with permacon

In a flat or apartment the balcony is often the only place where you can enjoy the outdoors. But even if you have a house with a garden, a balcony is often a delightful addition where one can retreat quietly or just enjoy the view. A balcony is often made from reinforced concrete. In order to prevent it from being unsightly, or the suspension getting damaged, it is wise to waterproof your concrete balcony. In this article we look at the structure of a balcony, the effect of moisture on the structure and appearance, and we present you with the solution for a totally waterproof balcony.

The construction of a balcony

Protect your concrete with Permacon

Balconies can be constructed in many different ways. Sometimes the balcony is literally a stacking of balconies below it, or it is placed in columns, but often the balcony hangs from the house. That can be done via beams that have been pulled through the construction of the house, or with anchors which are attached to the facade. The floor of a balcony will often be of reinforced concrete as well. Reinforced concrete is a concrete structure where concrete is poured around a frame of steel wires. Thanks to this reinforcement, the construction is much stronger than concrete without reinforcing, and it prevents the concrete floor from sagging, damaging or even collapsing.

The impact of moisture on your balcony

Concrete waterproofing with Permacon

Concrete – a mixture of cement, sand, gravel and water – has pores and is not completely waterproof by itself. Especially when small damages create holes, water will be able to penetrate it. With a balcony in which reinforced concrete is used, and also other metal is incorporated in the support structure, the probability exists that at any point in time the metal gets exposed to water and oxygen, and starts to rust. The rusting metal expands, and will push the concrete and the construction apart. This process is called concrete decay and can be identified by different things.

Ugly rust spots in the concrete are the least of the problem, far worse is pieces of concrete letting loose, which endangers people underneath the balcony. And eventually, the construction itself can collapse, with disastrous consequences. In 2009, for example, the combination of concrete decay and some rusted metal anchors, caused the collapse of massive brick facade panels in The Hague (in the Netherlands). In this particular case, there was only material damage, but if the same thing would happen with a balcony or gallery with people on it, it would be a disaster.

Waterproofing a balcony

Often, the concrete of the balcony is covered with a sealing or protective layer. If that is the case it is important this layer remains in good condition, and receives maintenance when necessary. However, if there are parts of the concrete which come in direct contact with the outside air, or when solely concrete is used, then it is useful to actually make the concrete waterproof. Permacon is the ultimate solution for this. Permacon makes concrete completely and permanently waterproof and stops rising damp. Permacon thereby prevents the formation of concrete decay, and also keeps your balcony free from algae and fungi.

Permacon protects your concrete and stops rising damp.

Permacon is an especially effective product. Concrete always has pores, and often small cracks and other openings. Permacon ensures that each pore or opening in the moisture exchange area – which is a layer of about 2 centimeters measured from the surface – is saturated with an insoluble gel. Normally moisture can reside in these gaps, but the solid gel that Permacon creates, is not liquid and remains fixed in its place. This way, all rising damps or absorption of moisture is being stopped. The gel also fixes harmful substances such as chlorides, sulfates and other contaminants inside the concrete. Stronger and impenetrable concrete is the end result.

Our Permacon is a colorless and environmentally friendly water based liquid that can be easily applied by any do-it-yourselfer. For larger areas, such as an entire balcony floor, you can apply it with a low pressure spray, while for smaller surfaces and parts you can use a brush. The final result is even more impressive if you have your concrete balcony floor finished with a water-repellent coating like Oppercon. For waterproofing concrete floors, however, this is not necessary, it is already guaranteed with Permacon.


  • Very economical: 1 liter is sufficient for 44 ft2.
  • Available in 1 / 2,5 / 5 / 10 / 25 Liter.