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I am looking at designing a covered outdoor area using timber. I assume LVL is the correct product to span circa 20m.
The timber is external but undercover. It will not be exposed to the rain.
My client wants minimal maintentance.
What treatment is appropriate to the LVL and how long until first maintenance?

Woodsolutions Answer +

For a 20m span some kind of ‘engineered’ product would be needed since sawn timber is not available in such long lengths. Of course shorter spans could be supported with posts. For a clear span, LVL will be fine although for a higher quality appearance you could consider glued laminated timber (‘glulam’). LVL is produced with a structural grade face and is not generally used in appearance applications unless a rustic look is desired. While a 20m beam is theoretically possible to produce, it’s beyond the usual range of sizes used in domestic construction and likely to require a special order. We suggest you discuss lead times and transport considerations with an LVL producer. If the timber is shielded so it won’t get wet when it rains, preservative treatment is not necessary and the usual range of paints and exterior wood stains can be used. Maintenance will not be an issue if the timber is not exposed to the weather.


My benchtop has osmo oil and around the sink and in areas of high use, the finish is coming away. We have reapplied the oil, we have sanded and reapplied the oil and lastly throughly cleaned (with osmo cleaner), sanded and reapplied. Although the oil appears to be absorbed, almost immediately, it returns to the previous state. Any ideas?

Woodsolutions Answer +

It’s not possible for us to have a detailed understanding of all the finishes on the market. We don’t carry out our own tests and we are not familiar with Osmo Polyx. If you are not satisfied with its performance perhaps it’s something to take up with the supplier. Osmo Polyx appears to be an oil-based finish. As a general rule we don’t recommend oils or waxes for areas where contact with water is likely. In our opinion the most satisfactory treatment for timber benchtops adjacent to sinks is polyurethane, applied to all surfaces including the edges of cutouts and the underside of the bench, ie. a complete envelope. Polyurethane forms a barrier against water and liquid spills, can be wiped clean easily, and is resistant to heat. However, if you intend to switch to polyurethane, note that any residual wax or oil may interfere with its curing, so all traces of the previous coating must be removed.


We are looking to use a timber portal frame for a building we are currently designing. The building is quite simple, rectangular with metal sheet cladding. The portals are required to offer a clear span of 25m. Can you please advise what a rough lead time may be for such a product, and additionally could you provide some advice or reference to the fire resistance properties of these sort of portal frame products?

Woodsolutions Answer +

You will have to contact a company that produces timber portal frames to discuss lead times, for example Timberbuilt Solutions could advise you. They have a website here: www.timberbuilt.com.au. Regarding fire resistance, this can be calculated by reference to Australian Standard 1720, ‘Timber Structures’, Part 4: Fire resistance for structural adequacy of timber members. Possibly Timberbuilt can also advise on this point.

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