Figured out where my bathtub was leaking; all around the base of the tile surround where it meets the tub; whomever installed it left approx. 1cm gap between that goes right through to the vapour barrier and just threw a tonne of caulk into the gap to seal it to the tub. Problem is the tub wasn't framed in correctly along the back wall and there is no supports under each corner; when weight is on the corner of the tub rim it sags noticeably and created a separation between the caulking and the tub rim; hence the water leak.

Really hoping to solve this issue without ripping out the whole tub and tile surround; tight space underneath to try and squeeze in some bracing for the back tub corners; wondering if there is any products on the market to provide a gasket/seal etc.. Along the inside of the tub/tile rim (ie. An L-shaped design to fit against the edge and seal to the tub and tile preventing water from flowing through the gap and into the crawlspace.

Thoughts?

Can you post detailed photo of the gap and the tub itself ? Thanks. Back to you. Milo