LOSP
Light Organic Solvent Preservative system that delivers H2 or H3 protection without the swelling associated with water-borne treatments, keeping dressed sections stable.
Light Organic Solvent Preservative is a hydrocarbon-solvent-based treatment system that carries fungicides and insecticides such as permethrin and tebuconazole into the timber without raising grain or causing dimensional change. LOSP is widely used for H2 and H3 treatment of dressed pine joinery, weatherboards, fascia, window components, and architraves where dimensional stability and a paintable surface are critical. Treatment retentions and end-uses are governed by AS/NZS 1604.1. The solvent flashes off after treatment, leaving the timber dry, dimensionally stable, and ready for finishing. Buyers should note that LOSP-treated timber is generally more expensive than CCA or ACQ-treated equivalents, but its stability suits visible, painted exterior applications. Confirm the active ingredients listed on the end-tag.
Values and references on this page are indicative and drawn from common industry sources. Always verify the current AS/NZS standard, manufacturer data sheet or NIAA policy publication before relying on figures for design, specification or compliance work.
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