Ive been renting a house in a village in Bkk since May last year.

We just noticed a huge leak in the ceiling outside in the part of the building that covers the parking area (see pics attached) and I can tell from its location that its coming from the ensuite bathroom of the master bedroom and more specifically the shower area.

Im wondering how bad is this and how can it be fixed? Is it just a case of checking for leaking pipes and/or grouting up the bathroom better or are we talking about ripping out all the floor etc?

My other concern is that my landlord doesnt care about taking care of her house at all (even though its probably worth about 5m) and lives in Singapore. However my contract is up for renewal very soon so I guess I have that on my side but I really like this house and was hoping to renew.

I had a similiar problem in my house (which I own) and solved by re-grouting especially around the drain but also between the tiles. It was not necessary to remove the tiles to do so. However I did have to remove and replace the damaged ceiling.

There are waterproofing compounds you can buy to paint over the tiles - Bosny is one brand, it's a clear silicone. But first need to regrout and maybe put thick water sealant all around the drain area.

Obviously, your landlord should do this. What if you offer to do it and subtract the cost from the rent, sending her the receipts?

Obviously, your landlord should do this. What if you offer to do it and subtract the cost from the rent, sending her the receipts?

That's the way I do it too, let the tenant pay first and then they deduct it from the rent. Requires a bit of trust but so far worked out well.

I would remove the damaged ceiling first as it may only be a leaking drain pipe connection and can be fixed from below and grout will not help that.

You need to rip off that wet ceiling to 1) get at the source of the leak and 2) prevent toxic mold from ruining the whole house and your health.

^agree. Sometimes those problems are from rain that seeps in from places you just don't know. Get a box cutter and take out the affected area. If there is still a leak, then try to find source. If no leak now, then wait a while and if it doesn't reappear, then it's easy to repair the hole.

I would remove the damaged ceiling first as it may only be a leaking drain pipe connection and can be fixed from below and grout will not help that.

Yes your right and it also gives you a good view of the pipes. Check for dark stain tracks which might lead you to the problem.