When it comes to the fire protection of buildings and large structures, there is a lot to consider. Do you use concrete encasement? Is the steel exposed and is this exposed steel internal or in the elements? Do you have adequate active fire rating measures in place and what impact do these have on the structure in the case of fire? As we said, there is a lot to consider. But once you have made the choice to use a thin-film intumescent, your next decision is whether to use a solvent, or water-based intumescent. In this article we break down this choice.
First off, let’s start with the basics: There are solvent-based and water-based intumescents that exist in the market and have for a significant period of time. Aside from the obvious comparisons between the two types, there are a number of other things people should know about water-based and not-for-steel intumescents. These include:
- The advantages and differences between water and solvent-based intumescents
- That there are a new breed of intumescents now available that are suitable for application on timber (One example is Aithon pv33)
- They are low VOC, making it more suitable to apply around other trades with minimal to no impact on work being done. This thus improves construction timelines making them more profitable.
- Nullifire SC803 is water-based and can be roller- or brush-applied.
When making a decision between a solvent-based or water-based intumescent, it’s important to have the right information about these two types. So, let’s take a more comprehensive look at each of the points listed above in order to better understand these products.
What makes a water-based intumescent different to solvent-based products?
As detailed above, intumescent coatings can either be water-based or solvent-based. Each type works differently, so you need to know which one is the best option for your specific needs.
Water-based intumescent coatings are generally a safe, more eco-friendly, and less-chemically smelling option. Though it does still contain some solvents, the amount is minimal or in low concentrations. Since it doesn’t smell as strongly as solvent-based coating, it’s advantages when applied in close quarters, or in close proximity to other trades during construction cannot be understated. When it evaporates, the release of volatile organic compounds (VOCs) is minimal, a big plus and an evaluative criteria that more and more builders are taking note of. Using a water-based coat also decreases the fire risks of having too many potentially flammable materials in one area.
Traditionally – less so with the introduction of modern materials such as SC902 – Solvent-based coatings tend to be more resistant to weather conditions as well as temperature changes and humidity. They also dry faster. However, they can emit VOCs that are harmful to both people and the environment. Breathing in these VOCs can cause health problems, so solvent-based coats are not recommended for use in living spaces.
Now that you know the differences between the two general types, you can pick the right one that is required for your building and its different areas. Overall, you can’t go wrong with water-based intumescent paint since it’s versatile, and newer products have been formulated to better withstand changes in weather.
Can intumescents be applied on timber?
Whichever product you ultimately choose, an important feature that you must consider is its fire-resistance. Today, as more buildings are constructed to showcase key design criteria – such as exposed steel, large voids or the like – or are constructed from renewable materials such as timber or Cross Laminated Timbers (CLT), the use of the correct fire protection is essential. What is suitable for a large steel beam is not necessarily the right thing, or can be applied to the same thickness for slimmer beams. Similarly, what is suitable for steel is not suitable for timber components.
Using the right water-based coating for timber can be a vital part of your fire protection strategy. The longer the intumescent coating can withstand a the effects of a fire conflagration, the more time you give occupants to escape a while also allowing firefighters work to save the structure.
A product like the Aithon PV33, for example, can protect wooden structures for up to 60 minutes. It’s a transparent coating that leaves a wax-like finish upon application, allowing builders to still show off the gorgeous look of natural timber while protecting it against flames. When exposed to fire, it generates a thick carbon char layer that can withstand temperatures as high as 1,000 degrees Celsius. It can be applied on wooden walls, beams, slabs, and columns with a spray gun, roller, or brush. How it is applied is a question of speed and as such construction timelines – factors which can impact costs if you’re not careful.
What is the impact on construction?
An intumescent coating that can be easily applied without requiring special conditions or tools can help in keeping building costs down. For example, if you choose a solvent-based product, you would typically need to close off an area while applying the coating and waiting for it to dry due to the presence of VOCs. This effectively stops all construction work in that space, and it could lead to delays that affect project delivery.
This is another compelling reason for selecting a water-based intumescent for a building. The low number of VOCs present in this type of product allows construction work to proceed with little to no interruptions. This lets you stick to your timeline and hit the necessary project milestones on schedule, ultimately ensuring that construction costs stay within manageable amounts and profits remain unaffected.
Choosing water-based coatings also allows you to comply with environmental regulations on VOC emissions.
These regulations are mandated by governments in order to safeguard the health of both people and the planet. Be sure to check with your local government on the legal restrictions pertaining to VOCs so you can select the right product for your building.
What is Nullifire SC803?
Intumescents aren’t only essential for protecting wooden components. They are equally useful in safeguarding structural steel. Of the different products currently available in the market, Nullifire SC803 is one of the most highly regarded intumescent coatings.
Nullifire’s SC803 is a water-based fire rating intumescent (paint), trusted by builders, engineers and architects which cab be applied with either a brush or roller.
After applying it on steel with either a brush or roller, it can be top-coated with another layer for enhanced protection and durability as well as aesthetic appeal. It has low VOC emissions, making it a safe and environmentally sound choice for construction. It also has a high fire resistance ability that can last for up to 60 minutes. Another plus in its favour is that it’s compatible with seals and primers, so you can use a comprehensive range of products that complement each other well, further ensuring the quality of construction work.
While active fire protection components such as fire extinguishers and alarms are the most visible means of managing fire-related accidents, passive fire protection is a law-mandated requirement aimed at minimising damage and increasing the possibility of containing fires.
Intumescents, and specifically, water-based intumescents are some of the most important tools in any fire protection arsenal. With the market continually innovating and developing new products, builders and customers now have multiple options that are not only more fire-resistant but are also more eco-friendly.
When choosing an intumescent, there are many factors that need to be considered, such as its VOC emissions, its ease of application, and its intended use. Figure out the top qualities you want to include in your building project, and you should be able to select the correct product that can both satisfy your needs and meet legal requirements. And when you get stuck, and aren’t sure what to use or specify, or aren’t sure of the required thicknesses of products and how they may affect the choice of steel, ask us – our team of qualified Engineers is on hand to help you.
Get in Touch
Speak to the leaders in passive fire protection
You are about to download a file from the Permax site. Please note All technical advisory notes generated by Permax are based on research papers, indicative fire tests and any other existing evidence. These documents should not be used as an official evidence as design engineers should review the information and determine the reliability of the documents.
Permax constantly update the documentations based on the new fire testing outcomes and change of standards and regulations. To ensure the documents you read are up-to-date, please contact the Permax technical team.