Flooding Deck

I own a 16 year old unit immediately above shops that has a huge verandah / deck and garden. The deck has a concrete floor with a stencilled pattern on it. The stencil pattern is peeling up badly and needs to be redone. I am prepared to pay for this myself and am in the process of getting quotes. 

However there are associated problems that will be very expensive to repair and I would like to know who is responsible for the repair cost.

1. The deck ponds badly and doesn’t drain to the pits. Consequently the deck quickly becomes very slippery. I want to make sure the verandah slope is such that the water will drain to the pits.

2. A pipe draining water from smaller verandah’s above deposits runoff into the middle of my deck (down a supporting column). Some of the unit owner’s above have dogs and are washing urine (fortunately not worse!) onto my deck which then ponds. I want to cut a small channel with a grate on my deck to get rid of this waste.

3. The garden has a 0.3 metre high concrete wall to contain the garden. It is clear that no membrane exists as the base of the walls leach dirt onto the verandah. I would like to rectify this situation.

The only tradesman I have so far got to quote has told me that the stencil should last much longer than 16 years and stated that the concrete base had almost certainly not been etched with acid prior to laying the stencil.

Thanks in anticipation for the wonderful service you provide.