The Use of Sodium Hypochlorite in Pressure Washing
Sodium hypochlorite is a chemical compound most commonly recognised as bleach. In its diluted form, it plays a crucial role in the world of pressure washing, particularly in the cleaning of surfaces affected by mould, algae, mildew, and other tough stains. Its popularity in cleaning stems from its potent disinfectant properties and ability to break down organic matter. But what exactly is sodium hypochlorite, how does it work, and why is it so widely used in pressure washing?
What is Sodium Hypochlorite and the Science Behind It
Sodium hypochlorite (NaOCl) is a compound formed when chlorine gas reacts with sodium hydroxide. It is often found in household bleach and is renowned for its ability to kill bacteria, viruses, and fungi. The compound works by releasing chlorine molecules when applied to surfaces. These molecules disrupt the cell walls of microorganisms, ultimately leading to their destruction. This makes sodium hypochlorite an effective solution for sanitising and disinfecting a wide range of surfaces.
The science behind why sodium hypochlorite is so effective in pressure washing lies in its oxidising nature. When it comes into contact with organic materials like algae, dirt, or mould, it breaks down these materials at the molecular level. The compound reacts with the organic matter, breaking it into simpler, harmless substances. This powerful oxidising effect ensures that surfaces are thoroughly cleaned and sanitised in a short amount of time.
Why Sodium Hypochlorite is Popular for pressure washing
Sodium hypochlorite is popular in pressure washing because of its effectiveness and versatility. It can be used on a variety of surfaces, including brick, concrete, vinyl siding, and roofs. The compound is highly effective at removing organic stains, including those caused by algae, moss, mildew, and mould, which are common issues in outdoor environments.
Its popularity also lies in its ability to work quickly. When applied to a surface, sodium hypochlorite can begin breaking down organic matter almost immediately, delivering noticeable results in a short time frame. The fact that it is relatively inexpensive and widely available makes it an accessible choice for both professional and DIY pressure washers.
The Impact of Sodium Hypochlorite on Pressure Washed Surfaces
While sodium hypochlorite is highly effective in cleaning, it is important to understand how it interacts with the surfaces it’s used on. In general, sodium hypochlorite has minimal negative impact on most common materials, but improper use can result in damage.
One of the most significant risks is its potential to bleach or discolour certain surfaces. For instance, sodium hypochlorite can cause fading on coloured concrete or paint, especially when used in higher concentrations. This is why it is important to dilute the solution appropriately and test it on a small, inconspicuous area before applying it more widely. The solution’s strength can be adjusted by varying the dilution ratio.
For our regular pressure washing services in Edinburgh, a typical mix might involve 1 part sodium hypochlorite to 3 parts water. For tougher stains or darker marks, a 50/50 mixture is often used. In cases of extreme mould or mildew build-up, a neat solution of sodium hypochlorite may be necessary. However, it’s important to understand that excessive use of concentrated bleach can lead to damage such as corrosion of metal surfaces, deterioration of wood, or fading of outdoor fabrics.
Research into sodium hypochlorite’s effect on surfaces is ongoing, but industry experts agree that caution should be taken when applying it to sensitive areas. Studies have shown that regular exposure to high concentrations of bleach can weaken certain building materials, which is why it’s essential to follow recommended safety protocols and dilution guidelines.
The Application of Sodium Hypochlorite in Pressure Washing
The process of pressure washing and sodium hypochlorite application involves using a range of tools, from traditional watering cans to more advanced pressure washing systems. Pressure washers often use attachments like the XJet or sniper spraying lances, which allow for efficient application of cleaning solutions. These tools help distribute the sodium hypochlorite evenly across a surface, ensuring that the cleaning solution covers all areas in need of treatment.
For larger cleaning projects, especially on roofs or high walls, the sniper spraying lance used in systems like the Gutter Vac system is invaluable. It enables users to apply sodium hypochlorite from a distance, reducing the need for ladders and improving safety during the cleaning process. The XJet system, on the other hand, mixes the chemical with water at the point of application, which ensures an accurate and controlled delivery of the solution.
When applying sodium hypochlorite, it’s crucial to follow the correct dilution guidelines. A typical ratio is 1 part hypochlorite to 3 parts water, which is suitable for most cleaning tasks. For stubborn marks or areas with heavy build-up, a stronger 50/50 mix may be more effective. In cases where the surface is severely stained, such as with ingrained mould or mildew, neat sodium hypochlorite can be used for maximum strength. See more here about the development of the UK pressure washing industry, where technology and chemical use has became more common.
It’s also important to note that sodium hypochlorite is often combined with surfactants in cleaning solutions. Surfactants are compounds that lower the surface tension of water, allowing the solution to spread more evenly across surfaces. This helps the sodium hypochlorite to penetrate deeper into the dirt or organic material, enhancing its cleaning power. The surfactant also helps the solution to cling to vertical surfaces for longer, increasing the contact time and effectiveness.
Safety Precautions When Using Sodium Hypochlorite for Pressure Washing
Despite its effectiveness, sodium hypochlorite is a powerful chemical that requires careful handling. There are several important safety measures that should be followed when using it for pressure washing. One of the key safety concerns is protecting surrounding plants and vegetation. Sodium hypochlorite can be toxic to plants if it comes into direct contact with them, causing them to wilt and die.
To minimise the risk to plants, it’s recommended to pre-wet the surrounding areas before applying the cleaning solution. Wetting the plants and soil creates a protective barrier that can help dilute the chemical before it has a chance to damage the vegetation. In addition, any runoff should be carefully contained to prevent it from spreading onto plant life.
The application of sodium hypochlorite should be done in cooler weather to avoid rapid evaporation, which can lead to reduced effectiveness. Once applied, the solution should be allowed to dwell on the surface for a minimum of 10 minutes and up to 30 minutes for tougher stains. This dwell time allows the sodium hypochlorite to fully break down the organic materials before rinsing them away.
Lastly, personal protective equipment (PPE) should always be worn when handling sodium hypochlorite. This includes gloves, goggles, and suitable clothing to protect against splashes. It’s also recommended to use a respirator if the area being cleaned is poorly ventilated, as inhaling bleach fumes can be harmful to your health.
