Tips & Installation

Builders' tips & information

 

Always adhere to highest industry standards and best practices when installing Niagara products. 

 



Do not install weatherboards, fascia or mouldings with a moisture content over 14%. We will not warrant any product that has not been maintained in accordance with our warranty specifications. 

Handling and storage

 

Unload timber products carefully by hand from the truck, or by using a mechanical lifting device. Never drag boards across the ground. To avoid bending, always carry individual boards on their edges. 

To minimise board distortion and moisture uptake all Niagara products must be stored in a dry, well-ventilated area, stacked on a flat surface at least 150mm above the ground, covered and out of direct sunlight and rain.

Moisture uptake before installation

 

Kiln dried radiata pine timber is hygroscopic. It will absorb moisture in a damp environment and release it in a dry environment (even when primed).

If timber absorbs moisture, some dimensional swelling may occur, which will disappear when the timber returns to its original moisture content. If the product shows signs of dimensional swelling allow time for it to dry out and return to the manufactured dimensions before installation.

All end cuts, notches, rebates and drill holes must be resealed with a suitable end-sealing product such as Envira Fast Dry End Seal. 

Proper application and nailing practices are essential for maximising the product performance and appearance. 

All nailing should be over studs with at least 35mm penetration into the frame. Nailing should be such that it does not restrict normal seasonal movement, so do not nail through overlapping pieces.

Selection of proper nails is important. For best holding power use JH hot-dipped galvanised or stainless steel annular ring shanked nails. Do not use plain or electroplated nails.

Hand nailing is recommended as nail guns can cause damage to the surface of the board. If a nail gun is used a non-marking attachment should be used to avoid damage to the board surface. Nails are to be countersunk (punched) by 2mm and must be filled immediately to avoid moisture uptake around the nail head.

Pre-drilling near the ends is recommended as a precaution to avoid the possibility of end splitting. We recommend the use of scarf joints. Butt joints can be used without an expansion gap, but these must be flashed. Joints should be staggered up the wall. Scarf joints should face away from the prevailing winds.

Prime all nail holes with a suitable premium exterior wood primer and fill holes with an exterior grade wood filler.

Sealants must not be relied upon for primary weather protection, they are used to assist with weathering at joint and laps only.

All filled areas must be spot-primed prior to top coating. 

The primer will not protect against the possibility of moisture uptake, which can result in dimensional swelling.

To avoid shrinkage lines it is essential that if swelling is evident, the product should be given time to dry out and return to its equilibrium moisture content and manufactured dimensions before application of any final coating system. 

Application of the first top coat prior to installation will help protect against moisture uptake during construction.

Use colours with a Light Reflectance Value (LRV) of 45 or more and with a gloss level of above 10%. Timber is a natural product and resin is a natural constituent of the pine species.

Resin bleed is rare,but will most likely occur in hot conditions, or where the product has been painted a darker colour. In the case of a resin bleed the following is offered as a guide:
1. Scrape off exposed resin.
2. Wipe with a cloth damp with solvent - mineral turpentine is ideal.
3. Sand back exposed area.
4. Apply Zinsser BIN Primer Sealer, following the instructions on the product.
5. Allow to dry.
6. Apply two coats of premium exterior grade paint.

Two top coats of quality house paint should be applied within six weeks of the product being installed. Irrespective of when the top coats are applied, ensure all loose material and dirt is removed. Some sanding and spot priming may be required.  

It is the painter’s responsibility to ensure all surfaces are prepared correctly prior to painting, including ensuring the primer is well adhered to the timber substrate and all surfaces are in a suitable condition for subsequent top coats.      

Do not top coat timber that has moisture-related dimensional swelling as this will help avoid shrinkage lines that may occur as the timber returns to its equilibrium moisture content and original machined dimension. This applies especially to weatherboards and fascia.

All preparation and painting shall be carried out in a good tradesman-like manner and to the requirements of the current AS/NZS 2311 Guide to Painting of Buildings, paint manufacturer’s data sheets and to be applied by applicators with the necessary equipment and experience, and under the appropriate environmental conditions to ensure that the potential of the paint system is maximised. 

For weatherboard painting guidelines click here.

All painted exterior surfaces should be washed at least once a year. Do not use a water blaster. Up to 10 years can be expected before a repaint is required, however this will depend on the colour, type and quality of the top coat and the preparation of the surface prior to applying the first top coats. 

To ensure timber products achieve the durability and long life you expect, it is essential a protective paint system is maintained in good condition and not allowed to deteriorate.

Visit the 'Caring for your paint' page on the Resene website for additional advice:
http://www.resene.co.nz/homeown/probsolv/prob9.htm

Refer to: BRANZ Good Practice Guide Timber Cladding • NZS3604 & E2/AS1.