Before You Start: The Most Common Cladding Installation Pitfalls

Following the positive response from customers to our recent blog on some of the most common decking installation mistakes, we thought now was the perfect time to turn our attention to cladding. Whether you’re still weighing up your options or preparing to install boards you already have on order, there are a few common pitfalls that are well worth being aware of before you begin.

Some mistakes don’t just affect the appearance of your finished project. In some cases, they can lead to costly repairs and cause serious, irreversible damage to your cladding boards, resulting in extra time, expense, and unnecessary hassle.

By the end of this article, you’ll know how to avoid the most common issues customers face when installing cladding boards. The good news? With just a little planning and the right approach, these pitfalls are easily avoided.

Before jumping straight into the installation process, it’s always worth taking a moment to make sure you’re fully prepared. As with any project, a little planning at this stage can make a big difference to the finished result.

Composite and fibre cement cladding boards are manufactured in batches to achieve a consistent appearance, but it’s still completely normal for subtle colour variations to exist from board to board. This is intentional, as many cladding products are designed to replicate the natural variation you’d expect from real timber.

For this reason, we always recommend laying out all your boards before fixing them in place. Doing so allows you to assess any colour differences and arrange the boards into an order that creates a more natural, evenly blended finish. Mixing lighter and darker boards across the façade helps avoid obvious blocks of colour forming in one area.

Skipping this step can lead to visible patterning that looks unnatural and detracts from your project’s overall appearance. Spending a few extra minutes planning your layout is a simple, effective way to achieve a balanced, professional finish.

When it comes to following instructions, many of us like to rely on instinct and experience. While that approach can work just fine when putting up a bookshelf, larger projects, like cladding an external wall, are a different story. In these cases, it’s important that you respect the materials and the way the manufacturer intends their products to be used.

Manufacturers provide detailed guidance for a reason. Installation instructions cover everything from recommended trims and fixings to spacing, orientation and ventilation, helping to ensure your cladding system performs as it should and only uses fully compatible components.

While installation methods may seem similar across cladding types, subtle differences matter. A composite board from one brand can behave very differently from another, and what works for fibre cement won’t necessarily apply to composite systems.

That’s why we strongly recommend reading and following the manufacturer’s instructions. They offer clear, step-by-step guidance and help protect your warranty. If products aren’t installed as advised, most warranties become void, often leading to unnecessary costs, delays, and hassle to put things right. For all our Cladco cladding installation guides, simply click here to view the full collection.

If you’re new to cladding, it’s natural to think the goal is to make the system as airtight and watertight as possible. However, this approach can lead to serious problems later, including significant damage to your cladding boards.

All Cladco cladding boards are designed as rainscreen systems, which means a suitable waterproof layer must be installed behind them. Rainscreen cladding protects the structural wall from the elements but isn’t designed to carry structural loads. It consists of an outer layer of cladding panels and an insulated, airtight backing wall, separated by a ventilated cavity. While some water may enter this space, the rainscreen’s main role is to shield the building from rain.

For the system to work effectively, you must leave adequate gaps between boards and at the perimeter to allow for natural expansion and contraction as temperatures change. These movements are most noticeable in timber and composite cladding because of the natural fibres within the boards.

Fibre cement cladding boards tend to expand and contract far less than other cladding materials, but it is always worth checking first with the manufacturer's installation guide to make sure your installation does not encounter any issues.

Failure to leave sufficient space between your cladding boards can lead to boards warping and cracking under pressure when they expand. Leaving gaps that are too large will cause the system to fail when the boards contract in cooler conditions.

The good news, when it comes to cladding, is that most types can be installed either vertically or horizontally, giving you the flexibility to achieve a finish that best suits your property’s character. However, there are exceptions to this rule that can catch customers off guard. Some products can only be installed in a specific orientation, such as Cladco fibre cement lap wall cladding, which must be installed horizontally.

Board orientation is crucial for proper water drainage and airflow behind the cladding. Incorrect orientation can lead to water ingress, staining, and poor ventilation. Beyond performance and appearance, installing boards the wrong way will also void the product warranty, turning what seems like a minor detail into a costly mistake.

For anyone installing cladding for the first time, leaving a gap between your building and the boards might seem counterintuitive. After all, you want to keep your property protected from the elements and free from unwanted pests.

However, for an external cladding system to work effectively, it’s essential to leave an adequate gap behind the boards to allow for sufficient airflow. By allowing air to circulate freely, it helps the system breathe and prevents moisture from becoming trapped behind the cladding boards. Keeping this area dry is crucial for protecting both the cladding boards and the substructure from rot and long-term damage.

Always be sure to carefully check the manufacturer’s installation instructions before you begin, as the recommended ventilation gap should be clearly specified. The required gap will also vary depending on the type of cladding being installed. At Cladco, for example, our Signature and ProClad composite cladding boards require a minimum 10mm ventilation gap at the bottom edge (between the cladding and the floor) and should be installed using minimum 30mm battens, while our fibre cement click cladding requires at least 30mm, and fibre cement lap cladding needs a minimum gap of 38mm.

Don't forget: all Cladco cladding ranges are rainscreen systems, so water will eventually get behind the boards. Without adequate ventilation, this can cause the boards and battens to become damp, increasing the risk of rot and mould, which may damage both the substructure and the boards.

At this point, you may be wondering about the insects and pests that could potentially find their way into the space behind your cladding. Well, fear not. This is where the simple but effective aluminium perforated closure comes in. These lightweight perforated trims are designed to seal off exposed edges while still allowing airflow, preventing insects and other pests from gaining access behind the boards.

The temptation to cut corners during an installation, whether to save time or materials, can easily catch customers out. When manufacturers state that abutting cladding boards must be fixed to double joists, some assume this is overkill and that a single joist will work just fine. Unfortunately, this mistake can lead to serious issues over time.

Installation instructions are designed to prevent long-term problems, and the requirement for double joists at abutting board ends is one of the most important to follow. Think of the cladding substructure as a skeleton. Although hidden once installation is complete, it provides the support that the entire system relies on. Fixing two board ends to a single joist places excessive strain on it, which it simply isn’t designed to handle. Over time, this can cause boards to move and become loose, leading to further issues.

While we're on the subject of abutting cladding boards, most standard installations where two boards meet on a double joist require an expansion gap between the boards to allow for natural expansion and contraction.

If you want to achieve a cleaner, more refined finish, you can use a mitred edge when butting two composite cladding boards together, as shown in the image above. This angled cut creates a neat join and allows the boards to sit closely for a more seamless appearance. Because one board will be slightly longer than the other, careful measuring and planning are essential to ensure the join lines up correctly. Please note that even with mitred joints, an expansion gap must be left around the perimeter of the cladding to allow for lateral movement.

As we touched on earlier in the ventilation section, if you’re new to cladding, it may seem logical to try to seal every gap in a cladding system. However, this is never recommended. When cladding the exterior of any building, it’s important to leave suitable ground clearance. This means ensuring there is a gap between the bottom of the cladding boards and the ground below.

Failing to leave adequate clearance means your cladding boards will be exposed to standing water, which will lead to water ingress. Not only will this stain your cladding boards and spoil their appearance, but over time, it can also compromise the integrity of the boards themselves. Left unchecked, this often results in the need to replace sections of cladding, leading to avoidable cost and disruption.

The amount of ground clearance required will depend on the material and type of cladding being installed, which is why it’s essential to follow the manufacturer’s recommendations. At Cladco, for example, we recommend a minimum gap of 10mm between the ground surface and the base of the cladding starter trim (for fibre cement) or starter strip (for composite cladding).

After investing plenty of valuable time, effort and money into planning your cladding installation, it can be tempting for some to try and cut costs. However, when it comes to fixings and accessories, this is one area where cutting corners can quickly undo all your hard work.

External cladding systems rely on every component working together, and fixings play a fundamental role in keeping boards secure, aligned and performing as they are supposed to. Using unsuitable fixings, or even the right fixings in the wrong way, can lead to long-term problems that are difficult and costly to put right.

Because cladding is permanently exposed to the elements, stainless steel fixings are usually recommended. These are designed to resist corrosion and rust, helping to ensure the boards remain securely fixed for years to come.

Choosing the correct screw type and screw length is just as important. While it may be tempting to reach for those spare fixings you have stashed away in your garage or work shed, using screws that haven’t been specified by the manufacturer can also lead to issues. Screws that are not the specified size will not adequately secure the boards to the battens. Using screws that are too short can also lead to overtightening, which may damage materials and restrict natural movement. We recommend using reliable, corrosion-resistant M4x40 stainless steel wood screws for all Cladco cladding installations, which are easy to install with the use of a PH2 screwdriver bit. If alternative fixings are used, the Cladco cladding warranty will be void.

Yes, you’re right, this article is mainly focused on installation pitfalls. However, this is one common post-installation mistake that’s well worth mentioning, as it can have a real impact on how your cladding looks and performs over time.

Many customers fall into the trap of assuming that once their cladding is fully installed, it's a case of mission accomplished. While the hard work is certainly behind you at this stage, ongoing care still plays an important role in ensuring your cladding looks its best for many years.

Fibre cement and composite cladding are both lower-maintenance alternatives to timber cladding, but they’re not entirely maintenance-free. If you want your cladding to retain its clean, fresh appearance throughout its lifespan, it’s important to keep on top of aftercare.

For composite cladding, a stiff-bristle brush can be used in everyday cleaning tasks, such as removing leaves. If you need to remove dried dirt, tree sap or bird droppings, warm water mixed with a household detergent and applied with a sponge or soft cloth is recommended. Once the boards have been hosed down with water to remove any excess soap, we recommend wiping the boards with a cloth to remove any remaining residue and help prevent watermarks from appearing.

Our very own Cladco decking cleaner is a fast-acting formula that you can use on our composite cladding boards to achieve a clean, professional finish, available in a 5L bottle, perfect for large and small projects.

When it comes to fibre cement boards, a stiff brush isn’t recommended, as this can damage the painted surface. Instead, a soft wash cleaning method is the safer and more effective option.

Soft washing uses a low-pressure application of a chemical-based cleaning solution, which allows moss, algae, bacteria and other organic build-up to be removed without the risk of surface damage associated with high-pressure jet washing. Once applied, the solution should be left to work before being gently rinsed away with clean water. This approach provides a thorough clean while helping to preserve the finish of your cladding.

Now that we’ve walked through some of the most common mistakes customers encounter when installing cladding, you should now feel much more confident and better prepared to navigate these potential issues, setting your project up for success.

Remember, manufacturers provide installation guides, diagrams, videos and technical support to help ensure products perform exactly as intended. Following this advice and using products as intended will significantly reduce the potential for mistakes occurring during and after installation. And if anything isn’t clear, most manufacturers have knowledgeable teams on hand to offer guidance and support before problems arise.

For Cladco customers, if you ever need assistance during your project, our friendly and knowledgeable Sales Team is always happy to help you. You can call us on 01837 659901 or email [email protected] for expert advice at any stage of your installation.