Treated, Primed and Ready to Paint
LOSP stands for Light Organic Solvent Preservative — a treatment method that carries preservative into the timber using a solvent rather than water. Because LOSP does not introduce water into the wood, it leaves the timber dimensionally stable with minimal swelling or raised grain, which makes it especially well suited to dressed, finished products like exterior trim and joinery where stability and a clean surface matter. LOSP-treated pine is typically rated to H3 hazard class, meaning it is suitable for exterior, above-ground use exposed to the weather but not constantly wet — exactly the conditions exterior trim experiences. “Primed” means the timber has been coated at the factory with a primer, so it arrives paint-ready: you simply apply your exterior topcoat(s) rather than having to prime on site. This saves a labour step, improves coating adhesion and gives a more consistent, professional finish. The combination — treated for protection, dimensionally stable from LOSP, and pre-primed for painting — makes primed LOSP the efficient, reliable choice for fascia, bargeboards, window and door surrounds and exterior mouldings. As with all treated timber, any cut, drilled or notched surface must be re-sealed with a suitable preservative to maintain the treatment envelope.
Why Choose Primed LOSP
Specifications
Timber
Radiata Pine, dressed for trim/joinery profiles
Treatment
LOSP (Light Organic Solvent Preservative)
Hazard class
Typically H3 — exterior, above ground, not constantly wet
Finish
Factory-primed — paint-ready (apply exterior topcoat)
Key benefit
Dimensionally stable; minimal swelling / raised grain
Common uses
Fascia, bargeboards, window & door surrounds, mouldings
Critical practice
Re-seal all cut / drilled surfaces with preservative
Where Primed LOSP Performs Best
Fascia and bargeboards.
Window and door surrounds and reveals.
Exterior mouldings and trim.
Eaves, soffit trim and exterior joinery components.
Painted exterior detailing on new builds and renovations.
Any above-ground exterior trim that will be painted.
Working With Primed LOSP
Primed LOSP is fixed using standard trim and joinery practice. Apply your exterior topcoat(s) over the factory primer following the paint manufacturer’s guidance — painting all faces and edges, including cut ends, gives the best protection and finish. Critically, re-seal every cut, drilled or notched surface with a suitable preservative before fixing, because cutting exposes untreated inner timber and breaks the LOSP treatment envelope. Use corrosion-resistant fixings appropriate to exterior use, and prime and paint any exposed fixings or filler. Detail the trim to shed water — avoid leaving end-grain exposed to direct weather, and ensure good flashing and drainage so the timber stays within its H3 above-ground service conditions. Maintain the painted finish over time, repainting as needed, to keep both the appearance and the protection intact. Store the timber flat, off the ground and protected before installation.
Get Your Free QuoteSustainable & Ethically Sourced
JVS Timber supplies primed LOSP from certified producers, treated to recognised Australian hazard-class standards. Plantation-grown Radiata Pine is renewable, and a treated, primed product that lasts and resists decay reduces replacement and rework over the life of the building — an efficient and responsible choice for exterior trim. Our team can help you select the right profiles and sizes.
Get Your Free QuotePrimed LOSP Sizes & Availability
JVS Timber supplies primed LOSP pine in the common exterior trim and joinery profiles — fascia, bargeboards, window and door surrounds, mouldings and dressed sections — factory-treated to H3 and primed ready for your topcoats. Supplied in a range of sizes and lengths, it lets builders and joiners skip the treating and priming steps and move straight to fixing and painting. Whether you need trim for a single renovation or volume quantities for a development, our team can confirm current profiles, sizes, lengths and competitive trade pricing, delivered Australia-wide. Tell us the profiles and sizes you need along with your delivery location and we will confirm availability.
Get Your Free QuotePrimed LOSP — Frequently Asked Questions
LOSP stands for Light Organic Solvent Preservative — a treatment that carries preservative into the timber using a solvent rather than water. Because it doesn’t add water to the wood, the timber stays dimensionally stable, which is ideal for dressed, painted exterior trim.