Protected Timber, Built for the Outdoors
Treated pine is Radiata Pine that has been impregnated with a preservative solution containing fungicide and insecticide components, protecting the timber against borers, termite attack and fungal decay. This protection is what allows an otherwise non-durable softwood to be used confidently in exposed outdoor and in-ground applications throughout Australia. Common treatment methods include CCA (copper chrome arsenate, recognisable by its greenish tint), ACQ, and LOSP (light organic solvent preservative), each suited to particular uses and hazard levels. Treated pine is rated by hazard class — a simple system that matches the level of protection to the exposure of the application. H2 is for interior, dry, above-ground use (protection against termites and borers); H3 is for exterior, above-ground use exposed to weather but not constantly wet; H4 is for outside, in-ground contact; and H5 is for the most severe in-ground and fresh-water applications. Specifying the correct hazard class is essential: using an H3 product in the ground, for example, will dramatically shorten its life. A critical rule applies to all treated pine: wherever it is cut, notched, drilled or rebated, the freshly exposed timber must be re-sealed with a suitable preservative so the protective treatment envelope remains intact.
Why Choose Treated Pine
Hazard Class Guide
H2
Interior, dry, above ground — protection against termites & borers (e.g. internal framing in termite areas)
H3
Exterior, above ground — exposed to weather but not constantly wet (e.g. decking, pergolas, cladding)
H4
Exterior, in-ground contact (e.g. fence posts, landscaping, retaining)
H5
In-ground & fresh water, severe exposure (e.g. retaining walls, posts in wet ground)
Treatment types
CCA (greenish), ACQ, LOSP — selected to suit use and hazard level
Critical practice
Re-seal all cut, drilled or notched surfaces with a suitable preservative
Where Treated Pine Performs Best
Decks, pergolas, verandas and carports (H3 above ground).
Fence posts, rails and palings (H3/H4 depending on ground contact).
Retaining walls and sleepers (H4/H5 for in-ground and wet).
Landscaping, garden structures and raised beds.
Outdoor structural framing and decking substructures.
Posts and poles for a wide range of outdoor uses.
Working With Treated Pine
Always select the correct hazard class for the application — in-ground elements must be H4 or H5, while above-ground exterior timber is generally H3. The single most important on-site practice is to re-seal every cut, notch, drill hole or rebate with a suitable timber preservative, because cutting exposes untreated inner timber and breaks the protective envelope. Treated pine is handled using the same safety precautions as untreated timber; follow standard guidance for cutting, fixing and disposal, and avoid burning treated offcuts. For decking and exposed structures, allow the timber to dry and then finish with a quality exterior decking oil or stain to manage surface checking and improve appearance; reapply periodically. Use fixings appropriate to the treatment and environment — hot-dipped galvanised or stainless steel fastenings are recommended, particularly for CCA-treated timber and coastal locations, to avoid corrosion. Maintain good ventilation and drainage around structures to maximise service life.
Get Your Free QuoteSustainable & Ethically Sourced
JVS Timber supplies treated pine from certified producers, processed to recognised Australian hazard-class standards. Plantation-grown Radiata Pine is a renewable resource, and correct treatment ensures timber achieves its full intended service life outdoors — reducing replacement and waste. Our team can help you specify the right hazard class and treatment type for your project.
Get Your Free QuoteTreated Pine Sizes & Availability
JVS Timber supplies treated Radiata Pine across the full range of common structural and landscaping sections — from framing sizes and decking joists through to posts, palings, rails and sleepers — in a choice of hazard classes (H3 for above-ground exterior work and H4 for in-ground use) and treatment types to suit your project and budget. Whether you need a small parcel for a backyard pergola or bulk quantities for a fencing run, landscaping job or development, our team can confirm current stock, sizes, lengths, treatment options and competitive trade pricing, with delivery Australia-wide. If you are unsure which hazard class or treatment your application requires, just tell us how and where the timber will be used and we will point you to the right product.
Get Your Free QuoteTreated Pine — Frequently Asked Questions
They are hazard classes that indicate where treated pine can be safely used. H2 is interior and dry; H3 is exterior above ground; H4 is in-ground contact; H5 is severe in-ground and fresh-water exposure. Always match the hazard class to the application — for example, fence posts in the ground need H4 or higher.