Preparation and Treatment of Exterior Cladding Materials
Preparation and Treatment of Cladding Materials
Before cladding is installed, taking the time to treat it properly can make a big difference in how it holds up over time. With New Zealand’s mixed climate, from coastal humidity to strong sun, applying protective finishes to your cladding helps it stay looking sharp and functioning well for years to come.
This guide covers the key prep tasks such as staining, painting, waterproofing and accurate cutting, with added insights on the types of treatments best suited to different materials and environments.
Key Activities
Staining or Painting the Cladding
Applying stain or paint before installation helps shield the cladding from sun, rain and seasonal changes. For timber cladding, this step is essential.
If you're working with timber weatherboards, it’s almost always required to stain or seal all four sides of each board before they are fixed in place. This includes the front, back and both edges. Doing this reduces the chance of cupping, splitting or moisture damage.
Once the cladding is installed, the face usually needs at least one more coat. In some cases, a second final coat will be added to build up protection and even out the finish.
What you gain:
- Better moisture control
- A more durable and consistent finish
- Less risk of movement or warping
- A longer life for your exterior cladding
Paint Types for Exterior Use:
- Acrylic paint is a common choice for timber and fibre cement. It is flexible, UV resistant and cleans up with water.
- Oil-based paint offers excellent coverage and is ideal for hardwoods or homes in high-exposure zones.
- Elastomeric paint creates a thick, flexible layer that helps fill small gaps and protect surfaces that may shift or crack over time.
Types of Timber Stains:
- Oil-based stains soak into the timber to enhance grain and provide deep protection.
- Water-based stains are fast drying, lower in odour and more environmentally friendly.
- Semi-transparent stains let the natural timber grain show through while adding colour and UV defence.
- Solid stains provide strong colour coverage and a uniform finish while keeping the wood texture visible.
Waterproofing the Cladding
New Zealand’s conditions make waterproofing vital. It protects cladding from swelling or decay while still allowing the timber or material to breathe.
Options include:
- Clear sealers for a natural look with added protection
- Paints that include built-in waterproofing components
- Penetrating oils that work especially well with timber to protect from within
Cutting to Size Before Coating
Before coating, it’s important to cut cladding to its final size. This means all ends and edges can be fully sealed before exposure to the elements.
Why this matters:
- Helps prevent swelling or distortion
- Reduces water absorption through cut ends
- Ensures an even and durable finish when installed
Considerations
Choose Products That Suit Your Materials and Location
Every cladding type responds differently to treatments. Match your stains, sealers or paints to both the material and the local environment.
- Timber suits breathable finishes that allow moisture to escape while blocking rain
- Fibre cement requires priming and a high-quality exterior paint
- Metal often comes pre-coated but can be recoated with specialised paint systems
- Plywood and board-and-batten should be fully sealed on all surfaces including the cut edges
Application Techniques Matter
The right tools and timing can make your finish last longer and look better.
- Mix and stir products before use to avoid colour differences
- Apply in dry, mild weather to avoid trapping moisture
- Allow enough time between coats for proper curing
- Use brushes or sprayers suited to the product for even coverage
Stay Safe While You Work
Paints, stains and sealers can contain chemicals that require care. Always work in well-ventilated areas and wear appropriate protective gear like gloves and masks. Follow product instructions closely.
Why It Pays to Prepare
Prepping cladding before installation adds real value to the exterior of your home. It helps prevent costly repairs, improves appearance and supports a longer lifespan for your materials. Whether you’re going for a painted look or a natural stained timber finish, the steps you take now will protect your home from day one.
