How to Renovate Metal Roofs with Elastometal.
ELASTOMETAL- A high performance elastomeric coating designed to waterproof metal roofs and protect against long term corrosion. Guaranteed 10 years.
INTRODUCTION
Metal sheet roofs are used worldwide to cover warehouses, factories, distribution centres and many other kinds of commercial buildings. They are permanently exposed to the environment subject to extreme conditions and stresses often in aggressive industrial and coastal environments. The metal roof sheets are continuously expanding and contracting adding further stress to the applied coatings.
THE PROBLEM
Most common metal sheets are made from steel or galvanized steel. They are coated in factory prior to installation, normally with plastisol or pvdf paint. Sometimes the roofsheets are left uncoated with only a thin layer of zinc protecting the roof from corrosion. Corrosion is a natural process of degradation, once the coating is breached the process accelerates under the paint film spreading rapidly leading to large scale detachment, metal loss and ultimately leaks. Disruption to production, damage to valuable assets and a reduction in employee working conditions and corporate image is inevitable and renovation works will have to be undertaken to avoid full replacement. Elastometal is a low cost solution designed for ease of application onto rusty roofs without the need for abrasive blast cleaning.
THE SOLUTION
Elastometal is an elastomeric waterproofing paint with 20% elasticity which can be applied direct to metal roofs without the need for abrasive blast cleaning. It is a single product solution requiring no additional primers providing an anticorrosion waterproof system which is easy to apply in one product. It is suitable for steel, galvanised steel, Corten steel, aluminium and plastisol coated sheets. Check out the video for live application
Applied on a roof, it creates a seamless and elastic rubber-like protective membrane that will protect against water ingress and corrosion for more than 15 years in the most aggressive environments.
Elastometal is a high performance single-component waterborne elastomeric anti-corrosion coating. It comes in an extensive range of RAL and NCS colours. It is UV resistant and 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 to which it is applied.
The applied thickness will depend on the slope of the roof and the local environment, but typically, on a roof with at least 4% slope, 350 microns dry film thickness is recommended.
Elastometal is one of our - Single Coating System - family.
SCS products solve specific application issues just by using one product. They are high quality products easier to apply, faster, more productive solutions. No additional products or primers are required. A single pack product with no associated mixing or pot life issues. Easy to apply by roller or spray with fast drying characteristics and unlimited overcoating times. It is a Dry fall coating reducing unsightly overspray.
All the products in the SCS family are ecological and sustainable high performance water based paints with virtually zero VOCs. Eliminating fire risks and other factors which are detrimental to health and safety in the workplace and the surrounding environment.
GUARANTEED PERFORMANCE
10 years guaranteed! With a lifespan of over 15 years! Contact AVACE for further information.
THE APPLICATION
Before getting started, download the technical and MSDS sheets from our website and read them carefully. If you have any questions, contact AVACE who will always be pleased to help. Download here.
- Weather:
Like for any outdoor project, try avoiding starting a job in rainy conditions. A minimum of 5°C and no rain foreseen during and immediately after application are necessary to apply the products. From 15°C and above working conditions are ideal enabling faster painted roofs. In extreme sunshine avoid applying in the midday sun and favour early-morning work or late evening.
If you are working in humid climates, and especially if it gets cold after sunset like in autumn 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 the dew point and avoid condensation.
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 without any problem.
- Surface preparation:
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. Ensure all loosely adhering materials are removed back to a firm edge.
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.
Perfectly cleaned surface. Some paint is still adhering and can be left.
Any remaining oil or grease should be removed with detergent. Mosses and mildew can be removed with proper cleaners. Always use biodegradable solutions that can be easily sourced, are very effective and protect the environment.
- 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 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.
- Edges
Also check the edges of the metal sheet plates. These are weak parts subject to corrosion. Remove any contaminants and apply a stripe coat of Elastometal by brush. You will notice that it perfectly covers these edges and will further protect them.
- Degreaser
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 neighbours 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 aluminium, galvanizing and stainless steel. Monoguard may be required as bonding primer over fresh galvanized and stainless steel.
- The equipment
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 use a roller although additional coats maybe required to achieve the recommended total dry film thickness. It will reduce the need for specialist equipment and overspray onto neighbouring areas.
Any type of paint brush are suitable. 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.
- Applying Elastometal
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. During the surface 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.
The first step is now to fix the reinforcement Roof Fleece on the seams.
You can use the 20cm ( 8 inch) wide Roof Fleece which can be easily cut at any length. The mesh is perforated, it is extremely strong and flexible. It can withstand enormous traction force without tearing.
You lay the mesh down evenly on the intersections of the metal sheets and brush a coat of 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 which may require the fleece are highly corroded areas, around chimneys or exhaust stacks where there can be aggressive emissions, areas subject to ponding and interfaces with walls. Let the paint dry for 4 hours before recoating. Depending on the ambient temperature this can be shorter or longer.
Elastometal is ready-for-use, stir it mechanically for several minutes and eventually dilute a little bit with water if you are working in hot weather conditions to slow its drying. But do not add more than 3% of water as this will affect its properties. If you are using an airless spray, you will be able to rapidly apply in one single pass the 320 microns wet film thickness of the first coat to achieve 175 microns dry film thickness. Spray Elastometal on the entire surface following the slope of the roof.
Elastometal has almost no overspray and is dry fall so can be easily cleaned after application. Although if it is warm and windy, try to work in a way that potential overspray does not come back in your fresh paint to obtain a smoother 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 a second layer of 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 than 3 days without rain fall. Finally finish details such as metallic objects, corners and edges by roller or brush. Continue to measure your wet film thickness during each application as this will help you to calculate your future dry film thickness. Approximately 0.8kg per square metre will be required to achieve a dry film thickness of 350 microns, although please allow for suitable loss factors when calculating your actual requirements.
The final dry thickness of 350 microns is important and needs to be in line with our recommendations as it will be your guarantee for the long-term performance of the Elastometal on the roof. Your metallic roof is now waterproofed and protected against corrosion.
After a full day of drying, a visual inspection of the roof is recommended before leaving the site. 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 Elastometal, a brush and some cleaning cloths. Elastometal is so easy to recoat by itself.
All the information above is based on field experience with frequently encountered application issues. Every project may have its own specific challenges which we can continue to address and recommend solutions. Contact AVACE on 01384 400355 or simply e mail your enquiry to sales@avace.co.uk.