What external wood filler for carport?

Rachel46

For This carport I've been advised that the timber needs to be sealed because its degrading. This is the vertical timbers around the edge of the ceiling. See pics for whole carport, close up on writing on timber as I dont know what type it is - this might help you, and close ups on the holes in the timber I need to fill.

My question is - what should I use to fill the holes in the wood? I dont know what caused them. I've had to fill hairline cracks in external timber before but not holes as big as this.

Please would you give me some advice. Thank you

JacobZ

Hi @Rachel46,

They are H3 treated glulam beams. Glulam (short for glued laminated timber) is made by bonding multiple smaller pieces of timber together to form one larger structural beam. You can see the straight lines along the beam where the pieces have been laminated. The holes you are seeing are the knots and minor imperfections of each individual timber that has been glued together to form the beam. This is why they end abruptly and follow the horizontal lines along the beam. They are imperfections in the timber which were present during manufacture, so they aren't really damage. From a structural standpoint, as they would have passed through a quality control process during manufacturer, there is no real cause for concern with these holes.

The timber itself is also unlikely to be degrading structurally. H3 treatment is designed for external use above ground, so what you are mostly seeing is surface weathering and fading from UV exposure rather than rot.

If you want to tidy up the appearance, you can fill those holes with an exterior grade timber filler such as https://www.bunnings.com.au/polyfilla-450g-exterior-timber-filler_p1210571 . Ensure you apply it as per the instructions, then sand it smooth once cured.

After that, you can seal the timber to protect it from further UV exposure using an exterior paint, oil, or a clear or tinted varnish depending on the look you are going for. This will help stabilise the surface and keep it looking consistent over time.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob