HOW TO WATERPROOF AND SEAL LEAKING BITUMEN ROOFS?
RD-ELASTODECK, A SEAMLESS, ELASTIC, SAFE AND EASY-TO-APPLY LIQUID COATING SYSTEM DESIGNED TO WATERPROOF MOST KIND OF SURFACES
Many flat roofs worldwide are originally protected with bitumen membranes. An effective and cheap method to cover warehouses, factories, houses and decks, and many other kind of buildings. They are subject to extreme conditions and stresses because of their exposure to outdoor weather conditions 24 hours a day, 7 days a week, all year round. The membrane is continuously expanding and retracting under the influence of heat and cold; it must not only resist to rain but also hail, snow, heavy sun light, erosion, etc … Conditions are terrible wherever their location in the world!
Due to the continuous movements of the construction and natural weathering, the membrane ends up one day or another by tearing itself apart, letting the way in to water. It’s the beginning of adhesion failures and of a process that will provoke leakages and lots of damages unless you stop it on time. Consequences for doing nothing are costly: stocks and production tools are damaged, furniture are ruined, some areas cannot be occupied, or production is interrupted resulting in huge economic losses!
Sooner or later, renovation works will have to be carried out.
In the case of complex industrial roofs with many slurs and areas hard to reach, repairing and sealing only areas where you think the leak might come from is not an effective solution as it can come from much further away than you think!
Flexibility to cover the old bitumen roofing may not be sufficient and there are real risks to see leakages very soon after, especially in the connections.
Removing the old membrane and laying down a new one is a tedious and expensive job.
RD-Elastodeck is the solution and will give a second life to your roof!
RD-Elastodeck is a better solution for refurbishing such roofs. A single-component water-based coating, safe and easy to apply that will limit the risks of having new potential leaks. Applied on a roof, it creates a seamless and elastic rubber-like protection membrane that will solve water ingress issues and last for more than 15 years depending on its location!
With its high flexibility and permanent elasticity, RD-Elastodeck will stick permanently to the surface and follow the dilatation movements of the roof.
The new membrane will be durable and highly resistant to different weather conditions, including UV rays, rain, hail, snow, warm, cold etc.
The system is successfully used in regions such as North America, Western and Eastern Europe, Mediterranean and Scandinavian countries, and South East Asia.
It is worth paying attention that RD-Elastodeck is lightweight. After the application of the coating and once that it’s dry, the additional weight on the roof is only about 1.3 to 3 kg per m².
RD-Elastodeck comes in various colors and does not necessarily needs to be top coated. However, we do offer options like RD-Thermoflex, a white solar Infra-Red reflective coating containing micro-ceramic beads that will improve the reflection of a bigger number of rays and reduce the heat transfer inside the building. More information can be found on www.rd-coatings.com.
RD-Elastodeck is also part of RD Coatings’ SCS – Single Coating System – family.
SCS products offers the possibility to solve specific issues just by using one product. It stands for easier, faster, higher productivity and quality solutions.
Our products being water-based, you eliminate risks like fire or explosion when bringing dangerous products on the job site; you avoid disturbing the surroundings with dreadful smells and emissions of dangerous solvents; you respect nature and the applicator by using more eco-friendly products.
10 years guaranteed! With a lifespan over 15 years! Contact your RD representative for the terms.
For the owner:
- Cost saving solution
- Highly efficient and durable system
- Guaranteed solution
- Water-based, safe, no fire risks
- Virtually no odor, can be used on occupied buildings without bothering occupants.
- Unlimited choice of colors
For the applicator:
- SCS solution
- One component product, easy application
- Low VOC, close to ZERO!
- Unlimited recoating window
- No pot-life
- No isocyanates
- Dry fall
- Fast to apply
THE APPLICATION – GETTING THE JOB DONE
Before getting started, download the technical and security sheets from our website and read them carefully. If you have any questions, contact your RD Coatings representative who will always be pleased to help. PDS RD-Elastodeck – PDS RD-Roof Fleece.
Select the thickness you will need as it depends on the climate where the roof is located.
If you are waterproofing a flat roof, or if the slope is lesser than 4%, it is important to use RD-Roof Fleece on the entire surface.
The total quantity varies from between 1,5 Kg/m² – 35 ft² per gallon in dry climates like Mediterranean to 3Kg per m² – 17 ft² per gallon in regions with a lot of rain and risks of ponding water or snow. In moderate Humid and Continental regions 2 Kg/m² – 25 ft² per gallon is the most usual.
Contact your local RD Coatings representative if you have any doubts.
Like for any outdoor project, try avoiding starting a job in rainy conditions. A minimum of 5°C / 41°F and no rain foreseen during and immediately after application are necessary to apply the products. From 15°C / 59°F and above, working conditions are comfortable and allows higher productivity. If the project is located in a very warm area where you expect heavy sunshine, you should avoid applying when the sun is hitting the most and favor early-morning work or late evening.
If you are working in humid climates, and especially if it gets cold after sunset like in fall or spring, be careful to finish working several hours before dark, otherwise you risk of having condensation covering the fresh paint and prevent it from drying. If you are working early in the morning, be careful of dew point and avoid condensation!
Tip: RD-Elastodeck has no recoating window. In other words, should the works be interrupted because of a sudden change in the weather, they can be continued later on without any problem!
The surface shall always be clean, dry, degreased, and free from any loose contaminant.
The most popular and fastest way to achieve this is to clean the surface using a high pressure washer powered at 220 bar / 3200 psi of pressure and a zero-degree angle oscillating tip. This method will remove contaminants, poor adhering old paint, and other non-adhering elements from the surface.
Any remaining oils or greases should be removed with soap. Mosses and mildew can be removed with proper cleaners. Please think of using biodegradable solutions that can be easily found and are very effective.
Verify if any existing coating is still adhering properly otherwise remove it.
Being water-based, RD-Elastodeck contains no solvents. This is important as the application of the coating will not reactivate solvents from older remaining systems like it’s often the case on bituminous surfaces.
At the end, rinse and brush off using clean water.
The surface shall be perfectly dry before applying the waterproofing system.
Edges and ledges
Also check the ledges and connections with walls, chimneys or other equipment that can be found on a roof. These are weak parts subject to water ingress faster than most other places. RD-Elastodeck can be used on most kind of mineral surfaces and as explained later, is easy to use with the reinforcement mesh to seal these weaker areas.
- The equipment
RD-Elastodeck is best to be applied by roller or by using an airless device. You can also brush it on specific areas with difficult access. If spraying is not possible, like in case of windy conditions, you can roll the paint. Rolling the paint will take more time and you will have to apply more layers to achieve the requested minimum thickness, but it remains a simple option.
The type of brush to use is very common. If you spray, use an airless with an output of minimum 180 bars or 2600 psi and a tip size between 0,017 and 0,023 inches.
If you use a roller, we advise to use 14mm / ½ inch polyamide rollers.
You checked the weather, your surface is properly prepared, and you have the right equipment. It is time to start applying the full waterproofing system.
RD-Elastodeck is ready-for-use, stir it mechanically for several minutes and eventually dilute up to 3-5% with water if you are working in hot weather conditions to slightly delay the drying.
Using RD-Roof Fleece will make the membrane untearable and very long-lasting. As you can see, the mesh is perforated, and high quality. You would need enormous traction force to tear it apart.
RD-Roof Fleece coated with RD-Elastodeck is tear-proof!
It is very important to use the Fleece in areas such as chimneys, edges, rims or railings, side walls, air con units, that are sensible areas.
We therefore advise to first start with this detail work. The Fleece comes in different width.
Cut the RD-Roof Fleece with sharp scissors to the size depending on the object. Apply it half on the roof and half on the object, then brush a coat of RD-Elastodeck on it and make sure that you coat at least 10 cm / 4 inches further off the fleece. The coating will flow through the perforated fleece and come into the contact with the surface. Make sure to cover well the fleece and let dry for 3 to 4 hours.
Check that you covered all the gaps, connections, edges you can find. Once you have finished the detailed work, you can start applying on the overall surface.
Start unrolling RD-Roof Fleece on the surface and distribute it evenly. Connections should have an overlap of 5 cm or 2 inches.
The Fleece is glued to the surface by rolling or brushing a first coat of RD-Elastodeck on top of it.
Let dry for 4 to 6 hours before applying the second coat. This first step takes the most time since you handle the Fleece and the paint in the same time.
The application of the second coat is very fast and can be done with the airless device for faster and more precise results.
Applying successive layers of RD-Elastodeck avoids having pinholes. The purpose is to have the waterproofing membrane applied evenly over the whole surface.
Think to measure your wet film thickness during each application as this will help you to figure out your future dry film thickness.
The final thickness is important and needs to be in line with our recommendations as it will be your guarantee for the long-term performance of the RD-Elastodeck waterproofing system.
It’s the total amount of material applied that matters, not the number of layers as long as you have a minimum of two.
Applying RD-Elastodeck with an airless device is the most efficient and contractors familiar with RD-Elastodeck will easily apply the entire system in two layers. It allows a fast application of a thick film together with a uniform, seamless surface with no marks. RD-Elastodeck has almost no overspray and is dry fall. If it’s warm and windy, try to work in a way that potential overspray does not come back in your fresh paint to obtain a nicer finish.
If you decide to apply the system by brush and roller, you will usually apply more layers to achieve the right thickness.
You can also pass over with a roller immediately after the application by airless to cover any empty spaces created by the tension on some joints.
Once the coat is dry, you can apply the following one. When applied in favorable good dry conditions, RD-Elastodeck can dry in 2 to 3 hours!
A GOOD TIP ABOUT THE COLOUR!
RD-Elastodeck comes in a wide variety of colours. Since it has an excellent coverage, we advise to use a different colour per coat. It will help you to perfectly distinguish one coat from another.
RD-Elastodeck is a waterproofing system that doesn’t need any top coat. But there are cases where a finishing coat could be useful like:
- in case of traffic on the roof, check our floor finishing products RD-Hydrograff HP and RD-Monofloor PU
- in case of solar reflective finish to keep Infra-Red rays away and avoid heat transfer inside the building, check RD-Thermoflex
- in case of chemical aggressiveness like near exhausts chimneys, check RD-Hydrograff HP Clear
Checking the work
After a full day of drying, a visual inspection of the roof is recommended before leaving the site for good.
As you will be walking on a soft and elastic freshly painted surface, think of wearing shoes with smooth soles.
If you need to carry out some touch ups, think of bringing with you a small can of RD-Elastodeck, a brush and some cleaning cloths. RD-Elastodeck is so easy to recoat by itself.
In some countries, it is usual to fill the roof with water to check the new waterproofing system and that there are no defaults. Even if the RD-Elastodeck waterproofing system is dry and cured after several hours and rain-tight, this check can be performed only after a minimum 7 days of curing.
Depending on how you are organized and the size of the job, it is possible to do all the work during the same day.
The roof is now sealed and waterproofed for many years!
Some references and final results
Keiko Corp. – Nagano – Japan
European Commission – Brussels – Belgium
Water treatment plant – Billerica MA – USA
Above information is based on field experience and frequently encountered applications. Every project may have its own specificities. Do not hesitate to contact your local RD Coatings representative if you wish more information.