Home How to restore a flat roof covered with a bitumen leaking roofing?
RD-Elastodeck is an elastomeric coating designed to waterproof aging and/or leaking bituminous roofing.
This liquid waterproofing system is safe and easy to apply, it adapts to almost any type of roof, and provides a high-quality, flexible, and elastic membrane with no seams or joints.
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Products presented
RD-Elastodeck 
Single-component liquid waterproofing coating for roofs, decks, and balconies.
Single-component liquid waterproofing coating for roofs, decks, and balconies.
RD-Roof Fleece 
Reinforcement mesh used in waterproofing systems for roofs, decks and screeds.
Reinforcement mesh used in waterproofing systems for roofs, decks and screeds.
How to restore a leaking bitumen membrane on a roof using RD-Elastodeck?
Introduction
Surface Preparation
Application
The problem
Many flat roofs are protected with bituminous membranes, also called roofing. This is an effective and inexpensive method for covering new constructions, such as warehouses, factories, houses, etc.
These membranes are exposed to extreme conditions and are constantly under the influence of heat and cold. They must withstand rain, hail, snow, sunlight, erosion, and more.
Like any material, the membrane wears out and eventually cracks or tears, allowing water to pass through. Some roofs have poor slopes, causing water to stagnate, which exacerbates the problems.
The consequences of doing nothing are costly: damaged stock and production equipment, ruined furniture, uninhabitable rooms, production stoppages, economic losses, mold, ceiling stains, and more.
While the source of the problem is sometimes clearly visible, it is often more complicated to determine because water can travel and come from a completely different part of the roof. Moreover, if the membrane is already aged, it is better to renovate the entire surface rather than making sporadic repairs.
Removing an old bituminous membrane and installing a new one is a tedious and expensive job.
The solution
RD-Elastodeck & RD-Roof Fleece
RD-Elastodeck is an excellent solution for the renovation of this type of roofs. It is a water-based, single-component liquid waterproofing system that is safe and easy to apply, just like paint.
When applied to a roof, it creates an elastic protective membrane with a rubber-like appearance, which will solve water infiltration issues.
Its estimated service life is over 15 years!
Thanks to its great flexibility and permanent elasticity, RD-Elastodeck permanently adheres to the surface and follows the expansion movements of the roof. It also blocks bitumen seepage and prevents brown stains.
Reinforced with the RD-Roof Fleece, the new membrane will be highly resistant to various weather conditions, including UV rays, rain, hail, snow, heat, cold, and more.
The benefits of the RD-Elastodeck system are numerous!
- Single-component: no mixing required, the product is ready to use;
- Water-based, non-flammable, almost odorless, and will not disturb neighbors;
- One product only, no need for primer or finish;
- Easy to apply, even partially depending on the weather, the work can be stopped at any time and resumed much later!
- Easy to maintain and repair;
- Suitable for both small projects and large surfaces;
- A proven solution on 5 continents!
- Wide choice of colors and options such as solar reflectance, chemical resistance, heavy traffic...
System(s)
Flat roof with a slope of less than 4% without stagnating water
| Product | Total consumption | Dry film | |||
| Reinforcement fabric | RD-Roof Fleece | The reinforcement fabric is rolled out on the roof before applying the coating. | |||
| Applied in a minimum of two coats | RD-Elastodeck | 2 Kg/m² 34 s/f-g | 900 µ 36 mils | ||
Flat roof or localised areas of flat roofs with risk of stagnating water for several days - Gutters
| Product | Total consumption | Dry film | |||
| Reinforcement fabric | RD-Roof Fleece | The reinforcement fabric is rolled out on the roof before applying the coating. | |||
| Applied in a minimum of three coats | RD-Elastodeck | 3 Kg/m² 16 s/f-g | 1350 µ 54 mils | ||
In some cases, it may be beneficial to add a finish to the RD-Elastodeck waterproofing system
| *** Finishing options to apply on RD-Elastodeck *** | |||||
| Product | Total consumption | Dry film | |||
| Solar reflectance / Cool Roof system | RD-Sunguard | 0,10 L/m² | 40 µ 1,6 mils | ||
| Protection for moderate traffic | RD-Monofloor PU | 0,27 L/m² | 100 µ 4 mils | ||
| Protection for heavy traffic | RD-Hydrograff HP Satin | 0,20 L/m² | 100 µ 4 mils | ||
| Protection against chemical contamination | RD-Hydrograff HP Clear | 0,20 L/m² | 80 µ 3,2 mils | ||
Application conditions
Environmental conditions (general requirements) :
• Minimum air and substrate temperatures: 10°C / 50°F for 24 hours.
• Maximum surface temperature: 55°C / 130°F.
• Maximum relative humidity: 80%.
• Surface temperature must be at least 3°C / 5°F above dew point.
• No threat of rain for 5 hours.
Interesting to know!
RD-Elastodeck has no restrictions regarding the overcoat window. In other words, if the work is interrupted, for example, due to a sudden change in weather conditions, it can be easily resumed once the surface has been cleaned.
/!\ Notes
• There must be no condensation on the surface during application and drying. Caution when working at the beginning or end of the season!
• Overnight drying between coats is generally recommended. However, drying rates for water-based coatings depend on temperature, humidity and wind.
• From 15°C / 59°F, working conditions are comfortable and enable higher productivity.
• If the project is located in a very hot area with very intense sunshine during the day, avoid applying the system when the sun is most intense on the surface, and prefer to work early in the morning, late in the afternoon or in the shade.0
Work preparation
The steps :
1. Check the roof drains, clean them, and remove any obstructions. Repair them if necessary.
2. Eliminate moss and lichens down to the root with an appropriate biocide or bleach (be careful with stains).
3. Degrease and clean the surface with RD-Eco PowerClean, a powerful biodegradable degreaser, or a good detergent.
4. Rinse and clean the surface with a high-pressure washer set to 220 bar / 3200 psi, equipped with a rotary nozzle with a zero-degree angle. This method will remove impurities and other non-adherent elements from the surface.
If there are concerns that high-pressure cleaning may introduce too much water into the roof and worsen infiltration, use a stiff brush and some water with a detergent such as RD-Eco PowerClean. Rinse gently afterward.
Before applying RD-Elastodeck, ensure the surface is clean, dry, degreased, and free of any contaminants.
Key considerations
Existing coating
Remove any parts that no longer adhere. Never paint over a poorly adhering coating! If there are blisters in certain areas, pierce them and cut them out, then remove the non-adhering coating.
Blisters
Blisters under the roofing may be the result of infiltration or condensation under the roofing due to the absence of a vapor barrier. In this case, installing ventilation chimneys for flat roofs may be appropriate. Don't hesitate to seek advice from a specialist.
Chimneys
Check the nature of the fumes. If they are aggressive, RD-Hydrograff HP should be applied as a finish coat around the chimneys over a few meters to increase chemical resistance.
Gutters
Gutters should be treated as areas with standing water and handled accordingly.
Parapets
Check their condition, as they may be deteriorated and could be the source of leaks. These can potentially be treated in the same way as the roof by applying RD-Elastodeck and RD-Roof Fleece, and/or covered with new coping.
Tiles and weights
Depending on the case and if possible, it is always preferable to remove any loose tiles or weights present on the roof, as the waterproofing issue may be underneath. If this is not possible, they will be treated with RD-Roof Fleece like other elements on the roof.
HVAC ventilation units
There is often standing water near ventilation units. Ensure sufficient thickness and divert water flow during application.
Frequent foot traffic
On some flat roofs, particularly in industrial settings, there may be regular traffic for various reasons. Apply a finishing layer of RD-Monofloor PU or RD-Hydrograff HP in these areas to protect the waterproof membrane.
Application of the RD-Elastodeck membrane
The steps :
Start by applying details such as gutters, parapets, chimneys, difficult access areas, etc. For these specific areas, RD-Roof Fleece is available in 20 cm wide rolls that can be cut to size.
Once these details are completed, move on to applying the system to the main surface.
The application of the RD-Elastodeck waterproofing system is very simple.
1. 1. Lay the RD-Roof Fleece roll on the surface and gradually unroll it while applying the first layer of RD-Elastodeck with a roller or brush to bond the fleece to the surface. Work in strips from one side to the other, overlapping the fleece by approximately 5 cm.
2. Allow to dry and apply subsequent layers to reach the recommended thickness.
Airless spray application is recommended for large surfaces, as it allows the recommended thickness to be achieved more quickly and in fewer coats.
However, roller application is also very fast and is recommended in windy conditions.
/!\ Choose a different color for each coat to ensure the prescribed quantity is applied everywhere.
Edges and borders
Extend the RD-Roof Fleece up the edges to at least 10 cm in height. Apply RD-Elastodeck another 10 cm above the fleece.
Application material
RD-Elastodeck
Brush, roller or airless (nozzle size: 015–023)
Application by airless is recommended and makes it easier to reach the recommended thicknesses.
Use a device that allows a minimum pressure of 180 bar / 2600 psi at the outlet.
RD-Eco Powerclean
Low-pressure sprayer. Allow to work, then rinse.
Tool cleaning
Clean with clean water only.
Product application
RD-Elastodeck
Product is ready-for-use.
Otherwise dilute with water when applying in warm weather conditions (> 25°C / > 77°F).
Drying time: (20°C - 68°F)
Touch dry: +/- 3 hours
Recoatable: +/- 6 hours depending on the thickness.
RD-Roof Fleece
Unroll and cut the fleece to the desired dimension and lay it on the surface.
Roll or brush a first layer of RD-Elastodeck or RD-Elastometal through the mesh.
RD-Eco Powerclean
Dilute between 5 and 20% in water, depending on degree of soiling.
Spray on and leave for 15 minutes.
Then rinse with a high-pressure cleaner.
VERS. S8-241112