# Forum Home Renovation Waterproofing  Waterproofing around timber posts

## MPD

I have 125mm square timber posts penetrating down through my Scyon balcony. I'm looking for opinions on the best way to waterproof around the posts. 
I'm concerned about how well the Davco K10 Plus membrane will adhere to the timber. I was thinking that I could stick on some Ardex STB Tape which will act as a bond breaker and give the membrane something to stick to. Alternatively, I could use the Gripsett prefabricated corners and paint the membrane onto them. I intend to stick tiles to the posts to hide the membrane where it comes up the posts and above the door tile level. 
There's probably better options I haven't considered. 
Any advice?

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## phild01

Would have been easier had you used gal posts.  As for what you propose I'd say there is a lot of uncertainty.  I would forget about tiling onto the post's timber face.  The best I can think of at the moment is to use aluminium angle around the base of the post and affix to the scyon with polyurethane.  If the post ever absorbs water or moisture then that is your main issue to consider, let alone shrinkage.  With the angle, the shrinkage issue can be maintained over time by applying a flexible sealant.

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## MPD

> Would have been easier had you used gal posts

  Indeed. Would have been even easier not to have bought the house in the first place! 
Regarding your solution, are you proposing that once the angle is in place, I waterproof over the horizontal leg then tile over that?

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## phild01

> Regarding your solution, are you proposing that once the angle is in place, I waterproof over the horizontal leg then tile over that?

  Yeah, like you would in a bathroom for a water stop. The angle would sit a bit higher than the tile level.

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## MPD

Thanks mate. Do you think a 25mm angle would be adequate? Also, since each post collar will be in four parts, how would you treat the joins prior to waterproofing?

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## phild01

> Thanks mate. Do you think a 25mm angle would be adequate? Also, since each post collar will be in four parts, how would you treat the joins prior to waterproofing?

  That is the trickiest part.  I am a sucker for overthinking but they could be dealt with small 10mm pieces of aluminium angle that sit just below tile level bonded to each intersection with the same polyurethane used to secure the long pieces to the scyon.  Bit over the top and you need to be able to cut 10mm pieces.  Even if you didn't do that, just accurate intersects with polyurethane (11fc or similar) would be enough and you could bond break those when waterproofing.

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