HOW TO RENOVATE METAL ROOFS / FACTORY ROOFS / WAREHOUSE ROOFS?
RD-ELASTOMETAL, A LIQUID APPLIED COATING SYSTEM DESIGNED TO
WATERPROOF THE SURFACE,
PROTECT AGAINST CORROSION
Metal sheet roofs are used worldwide to cover warehouses, factories, houses, and many other kinds 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 metal sheets are continuously expanding and retracting under the influence of heat and cold; they must not only resist wind driven rain but also hail, snow, heavy sun light, erosion, etc … Conditions are terrible wherever their location in the world!
Most common metal sheets are made from steel or galvanized steel. They are coated in the factory prior to installation either by a coil or powder coating process. Sometimes they are not coated at all and it’s the zinc layer that protects the sheets. Quality of these coatings may vary but one thing is for sure, Rust Never Sleeps and will one day start to appear, then comes the adhesion failures and it’s the beginning of a process that will promote leaks and corrosion unless you stop it. Consequences for doing nothing are costly: damaging stock, machinery and equipment, furnishings and causing some areas not to be occupied or a interruptions to production which could result in huge economic losses!
Sooner or later, renovation works will have to be carried out. RD-Elastometal will give a second life to your roof!
RD Elastometal is a one of a kind product which offers unequaled performance and longevity. RD-Elastometal is unique because it combines in a single product, high waterproofing properties with very high anti-corrosion properties.
Applied on a roof, it creates a seamless and elastic rubber-like protective membrane that will solve water entry (or water leaks) for more than 15 years.
RD-Elastometal is a high performance single-component waterborne elastomeric anti-corrosion coating. It comes in various colors, is UV resistant and therefore can be used as both the primer and finish coat. It’s 200% elasticity allows it to flex and bend on any kind of surfaces it is applied on.
The thickness to apply will depend on the slope of the roof and the environment, but typically, on a roof with at least 4% slope, 350 µ / 14 mils dry film thickness is the general recommendation. More precision can be found in our datasheets or by simply contacting your RD Coatings representative.
RD-Elastometal is also part of RD Coatings – 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 0!
- 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. Download here: RD-Elastometal PDS and RD-Roof Fleece PDS
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-Elastometal 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 300-350 bar / 4000-5000 psi of pressure and a zero-degree angle oscillating tip. This method will remove contaminants, poor adhering existing paint, and rust from the surface.
Hand- or power tool cleaning is also an option and is advised when more detailed surface preparation must be done on objects located on or adjacent to the roof such as exhausts, ladders, and heavily corroded bolts.
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.
You will always have to verify if the existing coating is still adhering properly.
Inspect and treat bolts:
It’s important to inspect the bolts which are used to attach the metal sheets to the structure. Defects should be repaired or replaced with new bolts. A spot coat of RD-Elastometal should be applied after inspection of the bolts. This will aid in the inspection process and provide added waterproofing and anti corrosion protection in this critical area.
Also check the edges of the metal sheet plates. These are weak parts subject to corrosion. Remove any contaminants and apply RD-Elastometal by brush. You will notice that it perfectly covers these edges and will further protect them.
An extra step that may depend on the location and the environment would be to use a biodegradable degreaser on the surface and get rid of any oils or greases. Observe the surroundings for any chimneys or neighbors expelling fumes as they may provoke the accumulation of contaminants on the roof.
Special alloys and smooth surfaces
Degrease, clean and lightly sand any non-ferrous metals such as aluminum, galvanizing and stainless steel. RD-Monoguard may be required as bonding primer over fresh galvanized steel, stainless steel, and RD-Multiprim on other smooth surfaces.
RD-Elastometal is best to be applied by brush on specific areas and airless sprayer on the main areas. If spraying is not possible, you can also roll the coating. Rolling RD-Elastometal will take more time and you will have to apply more layers to achieve the requested minimum thickness, but it remains a good 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 0,015 and 0,019 inches.
If you use a roller, we advise to use 14mm polyamide rollers or 3/8 inch nap 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 and anti-corrosion system.
As we saw during the preparation work, bolts and edges have been treated when necessary.
If you have a dry film measuring device, it’s time to measure the thickness of the existing coating on different areas. If you don’t have this device, no problem, you can use a wet film gauge like we explain further.
The first step is now to fix the reinforcement mesh RD-Roof Fleece on the seams.
You can use the 20cm – 8 inch wide mesh – RD-Roof Fleece – we provide and easily cut it at any length. As you can see, the mesh is perforated, and high quality. You would need enormous traction force to tear it apart. This is very important.
You lay the mesh down evenly on the intersections of the metal sheets and brush a coat of RD-Elastometal through the open weave mesh
You shall repeat this on all the intersections of every metal sheet. With some practice, you can do this operation with one man very easily.
Other areas may also need the use of the fleece:
- highly corroded areas
- places near chimneys or exhausts where there can be aggressive fumes
- areas where water could stagnate
- connection with walls or other elements
Let the paint dry for 4 hours before recoating. Depending on the weather this can be shorter or longer.
RD-Elastometal is ready-for-use, you may stir it mechanically for several minutes and eventually dilute a little bit with water if you are working in hot weather conditions to delay its drying. But do not add more than 3% of water in order not to diminish its anti-corrosion properties.
If you are using an airless spray, you will be able to rapidly apply in one single pass the specified wet film thickness of the first coat. You will spray RD-Elastometal on the entire surface following the slope of the roof.
RD-Elastometal 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.
Let the paint dry for 4 hours before recoating. Depending on the weather and the thickness you applied, this can be shorter or longer.
Apply you full second layer of RD-Elastometal on the entire surface the same way you did previously.
If interrupted in application we recommend that the areas to be coated be re-pressure washed or rinsed. Usually if the surface has sat for more that 3 days without rain fall.
Eventually finish details such as metallic objects, corners and edges by roller or brush.
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-Elastometal on the roof.
Your metallic roof is now protected against water ingress and corrosion.
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 measured before starting the works the film thickness of the existing coating, measure randomly the dry film thickness and compare it with what your initial measures to be sure to have reached the recommended average film thickness.
If you need to carry out some touch ups, think of bringing with you a small can of RD-Elastometal, a brush and some cleaning cloths. RD-Elastometal is so easy to recoat by itself.
Your assets lying underneath are safe! Your building’s value has increased!
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.