How to clad balcony sofit?

cgerke

I have a wrap around balcony. A basic timer frame with corrugated roof. I’m looking at cladding the underside. The options I see are, cement fibre, pvc or marine ply.

im leaning toward Marine ply as it seems lighter than fibre cement and cheaper than pvc. 

Anyone have any comments, thoughts or recommendations?

MitchellMc

Welcome to the Bunnings Workshop community @cgerke. It's wonderful to have you join us, and many thanks for your question about lining a balcony roof.

If you’re worried about the weight that the balcony frame can hold, the first step is to confirm whether the structure was designed to take a lining or if it’s only meant to support the roof sheeting above. In situations like this, it’s often worth checking in with an engineer or builder before committing, just to be sure the frame is up to it. Where a roof has been built with eaves or a soffit in mind, the usual approach is to use eave lining or 4.5mm fibre cement sheets. These are light enough that a properly designed frame won’t have any issue supporting them, and they’re ideal because they stand up to moisture and weather over the long term.

I’d be cautious with marine ply. While it is more moisture resistant than standard ply, it still needs to be completely sealed on all faces and edges to survive in an exposed outdoor environment. Even a small amount of water getting through can cause it to swell or delaminate over time. That isn't a concern with fibre cement, which is made for external use and will last perfectly fine outdoors with minimal maintenance.

Could you share a couple of photos of the frame? That would help in working out whether it looks like it’s capable of holding sheets, and give a better idea of what product would be most appropriate. My leaning would be towards 4.5mm cement sheets, but confirming the strength of the structure first would be the safest next step. Let me know if you need a hand uploading images.

Please let me know if you have any questions.

Mitchell