Hi guys, i am come across a thread there that mention resin injection can fix leaking.
Anyone mind to further explain it or can provide opinion whether it will fix my current problem ?

I did toilet/back extension with flat concrete roof by a noob person, it have leaking problem sometime when raining really heavily. however sometime it does not.

I consulted another contractor and he suggest I do awning to cover the concrete roof, somehow i come across this thread and I wonder whether this method will work.

He also told me the problem occur because the contractor do the extension in wrong way.
If there is no solution, it will cost a lot of money and time if Im going to redo/hack it.
He said the contractor do Picture A method, correct method should be Picture B. Last picture show leaking.

Thanks.

bro, what is gi flashing tuck ?
screed to fall maybe not possible because wall is a bit higher than roof.
concrete kerb is it make thick concrete to cover the joint area ?

it look like this

bro i think after contractor fix/water proof will also leak..mine is something like this too.

regarding my case, as i dont have money to demolish and rebuild, i do ajiya awning, it fixed the problem, but in very very heavy rain i can see 2-3 small water mark.
recently i cleaned the roof, clean away dust etc, paint the whole cement roof with undercoat and then paint. hope it will do. considering to put bitumen stripes around the roof sides/lines later

did them fix it bro?