What coating to protect a balcony/decking?

[Kal Ico]

Hi, I have a wooden balcony that has been painted with a proprietory seal/varnish type stuff. The problem is that it takes a beating from the sun and cracks appear. Rainwater gets in the cracks and then the rot starts. I've replaced a few of the planks over the years, but I hope there is a better way.

The planks are approx 15cm wide, 5cm deep, regular pine softwood.

Would something like Acrypol or another thick, bituminous roofing-type compound work? Wouldn't be so abrasion/wear resistant, but would fill in the cracks and hopefully keep the rain out.

Happy to hear all suggestions.

[Chris Bacon]

I'd be temp-ted to slosh some fungicidal treatment on it when it's dry, and just do that occasionally. Not sure what's good now, I looked up Cuprinol Five Star, but it does not seem to contain what it once did, so I can't actually recommend it. There're other products like Barrettine Premier Wood Preserver, which is fungicidal, you could look at that. I'd use something clear, certainly not "shed and fence treatment" or similar such rubbish.