How to repair and renovate damaged balconies?

The RD-Elastodeck/RD-Monofloor PU system makes it easy and quick to repair and waterproof balconies with a new finish in the shade of your choice.

The products you need

The problem

Balconies are generally subject to various degrees of wear. Some are used intensively and must withstand the wear caused by traffic and especially the legs of chairs, tables, and other stored objects. Others are used only occasionally, if not never.

Regardless, balconies are also subject to the weather which weathers down the materials year after year. Until the day when water begins to sweep through the waterproofing membrane into the concrete.

It’s the beginning of problems which will accelerate if we do not react quickly enough. The metal reinforcing bars will rust, the concrete will crumble and crack, the paint and pieces of concrete will start to come off, stalactites will form below in the neighbor's ceiling etc.

RD Coatings offers a quick and easy solution to fix this with the use of a waterproofing coating and a wear resistant floor coating for exterior that will withstand wear and weathering.

The solution


RD-Elastodeck is a one-component, water-based elastic coating that is applied in thick layers to solve waterproofing problems and block water ingress. Combined with the RD-Roof Fleece, it forms a flexible and tear-resistant membrane. The use of a liquid coating facilitates the application and makes it easy to reach corners, and perfectly cover the entire surface.

RD-Monofloor PU or RD-Hydrograff HP

Above a flexible and elastic membrane, it is necessary to protect it by the application of a harder coating, resistant to wear and UVs. The choice of one or the other product will depend on the final use of the balcony.

  1. For balconies with chairs and tables fitted with pointed feet, and/or a lot of traffic, we advise to apply RD-Hydrograff HP as a finish,
  2. For balconies with low or moderate traffic, and especially without sharp and scratching objects, we recommend the application of RD-Monofloor PU as a finish.

RD-Monofloor PU and RD-Hydrograff HP are available in a wide range of RAL and NCS colours or custom shades.


High quality acrylic elastomeric paint to repaint the underside of the balcony if it should be damaged.


High quality acrylic paint to repaint the underside of the balcony if it should be damaged.

Recommended products and quantities

RD-Elastodeck: between 1.5 and 2 Kg/ m²

RD-Monofloor PU or RD-Hydrograff HP: +/- 6m²/L

RD-Roof Fleece: Custom cut polyester mesh rolls.

Other products such as RD-Acryl W, RD-Cement Filler and RD-Unifix will be useful depending on the state of the balcony and the repairs to be carried out, and the RD-Elastoflex for the underside and the sides of the balcony.

All of these water-based products, you avoid:

  • Bring hazardous materials to the job site and eliminate fire hazards.
  • nuisances in the neighbourhood due to unpleasant odours during and after application;
  • emissions of harmful substances.

Benefits and expected performance of the system

The system will be very lasting if applied correctly and according to our recommendations.

However, the life expectancy of floorcoverings is extremely difficult to predict because it depends on many factors, such as the intensity and way it is used.

The system offers many advantages for both the owner and the applicator:

For the project manager/owner:

  • Cost-effective solution
  • Highly resistant and durable system
  • Environmentally Friendly
  • Water-based, safe, fire-free during application
  • virtually odourless, can be applied without disturbing neighbours
  • Wide choice of colours

For the applicator:

  • Ease of use
  • Mainly single component products
  • No solvents
  • Almost no COVs
  • Fast and simple application
  • Very long service life depending on use
  • Proven system

Prepare the job


As with any outdoor project, try to avoid starting a job in rainy weather. A minimum of 12°C / 54°F and no rain expected during and immediately after application are required to apply products safely. From 15°C / 59°F, working conditions are comfortable and allow higher productivity.

If the project is located in a very hot area with very intense sunshine during application, you should avoid applying the system when the sun is most intense and prefer working early in the morning or late afternoon.

If you are working in humid climates, and especially if it is cold after sunset such as in the fall or spring, be sure to finish the job a few hours before dark. Otherwise, you risk having condensation covering the fresh paint and preventing it from drying. If you are working at dawn, beware of condensation on the surface, avoid it!


Avoid carrying out waterproofing work in autumn, winter or spring when the weather conditions are sometimes too uncertain. RD-Elastodeck does not have a cover window. In other words, if the work should be interrupted due to a sudden change in the weather, it can be resumed later without any problem!

Preparing the surface of a tiled balcony

The waterproofing system can be applied directly to a tiled surface provided that the surface is carefully examined:

  • Control the stability of the substrate of the balcony; the good anchoring of the tiles, slabs or pavers, are checked by striking on the substrate. When necessary, they will be fixed with a mortar that does not shrink such as RD-Cement Filler.
  • Inspection of drainpipes and drains; they must be unblocked or replaced when they show bursts or cracks or have hardened.
  • After that, an effective cleaning must be carried out without using too much water to avoid a new saturation of moisture. We suggest using RD-ECO PowerClean, a powerful biodegradable detergent. 
  • Allow to dry well, especially if the support has undergone high pressure cleaning.

Preparing the surface of a concrete balcony

The balcony surface must be clean and degreased. Use RD-ECO PowerClean, a powerful biodegradable detergent.

If there is an existing waterproofing coating, it is preferable to remove it entirely since it is no longer a priori watertight. However, if its adhesion is sufficient and water ingress problems are caused by porosity or cracks, it is possible to leave it in place.

An existing paint layer can also remain if you checked for its good adhesion. If it peels off or flakes, it must be stripped. Decap Eco, a biodegradable paint stripper will help you.

Sides & edges

Check the sides and edges. These are vulnerable and quickly subject to water ingress, especially at the level of the guardrail fasteners. Repair large cracks with RD-Cement Filler and fill micro-cracks using RD-Acryl W.

Exposed concrete irons

If the concrete irons are visible, they are subject to corrosion. Remove the non-adhering rust with a metal brush and apply with a brush a layer of RD-Elastometal. Then cover with RD-Cement Filler.

You will normally need little RD-Elastometal, it is therefore also available in small 1Kg jars.

The equipment

RD-Elastodeck, RD-Monofloor PU or RD-Hydrograff HP can be applied using an airless sprayer or with a roller. The use of either process will generally depend on the size of the surface to be treated.

RD-Cement Filler is applied with a trowel.

RD-Elastometal can be applied by brush when it comes to small surfaces or detail work.

Specifications for an airless application

RD-Elastodeck: minimum output of 180 bar or 2600 psi and a nozzle size between 0.015 and 0.019 inches. 

RD-Monofloor PU: Nozzle opening: 0.015 to 0.021 inches - Pressure +/- 70 bar (+/- 1000 psi)

RD-Hydrograff HP: Nozzle opening: 007 to 009 – Pressure +/- 70 bar (+/- 1000 psi)

When the work is finished, simply clean your equipment with clean water or according to the equipment manufacturer’s manual.

The application

The single component products RD-Elastodeck, RD-Monofloor PU and RD-Elastometal are ready to use. Stir a few minutes mechanically before use.

RD-Hydrograff HP is a two-component product. Follow the instructions described in its data sheet.

Application of the first layer

Porous surface: apply a layer of RD-Unifix impregnation. The consumption will depend on the porosity of the substrate and is generally greater than 0.10 L/m².

Smooth surface: apply a layer of RD-Elastodeck diluted to 25% with water, with a consumption of +/- 0,3 kg/m².

Installation of the RD-Roof Fleece

RD-Roof Fleece comes in three widths: 20, 60 and 120 cm. Oder the size you believe most appropriate to the balcony.

Unroll and cut the fleece as you lay it. Place it on the floor, make sure to raise it by 10 cm on the sides. If there are overlaps of different pieces, make sure it is at least 5 cm.

If you raise the fleece on metal guardrail feet, glue it using RD-Elastometal. This will protect them against corrosion at the same time.

Application of the RD-Elastodeck waterproofing layer

Apply RD-Elastodeck (undiluted) directly on the fleece so that it sticks to the surface. Let dry.

Then apply one or more coats to entirely cover the RD-Roof Fleece. Follow prescribed quantities and a waiting time between layers of +/- 6 hours (at 20°C).

The application of the waterproofing membrane is now completed.

Application of the wear/finishing layer: RD-Monofloor PU or RD-Hydrograff HP

As explained above, the intensity of use will determine the use of one or the other.

Apply one or two coats of RD-Monofloor PU or RD-Hydrograff HP Satin (which is also available in matt or glossy).

How to obtain non-slip properties on the balcony ?

In case the balcony is exposed to heavy rain and can be slippery, you can increase its anti-slip properties very easily:

Sprinkle quartz or fine sand (dry!) on the last wet fresh layer of RD-Elastodeck and let dry. Brush the superfluous quartz with a broom once it’s dry.

Then apply the finish coat.

If you decide to apply two layers of finish coat, you can do this between the first and second layer.

Repair of the edges and undersides of balconies

It is better to wait a long time after the application of the waterproofing system before repainting the underside to leave the moisture still present the time to evaporate.

After controlling the moisture content, the salts discharges must be carefully removed by stripping and dusting. Repair hairline cracks with RD-Acryl W and use RD-Cement Filler if they are larger.

Thoroughly impregnate the surface with RD-Unifix and finish by applying two layers of RD-Elastoflex.

VERS.   S20-230901