How to waterproof and repair a damp corner of the floor?

[ivanptr]

One corner of our house in our bedroom can get damp and moist when it rains. 

Only this corner so far. 

At first we thought its happens because the finished ground level of the yard is too high (higher than bedroom floor). But after we took out the soil lowering the ground level, the problem still persists.

Visually we do not see any brick wall cracks.

One mate told us, "even" the ground level was too high, theoretically the interior floor should not be damp and the problem is the vapor barriers of our concrete slab failed.

The problem is , we dont know how we should approach this and from which kind of professionals we should seek help first

We contacted waterproofing companies and they told us that :
May we also suggest that the plumber double check the fall and that the diameter of the drainage pipe is of adequate size. It would be good to have the pl;umber look at the rest of your property as you may need some additonal drainage system put in place.

1) There is only a rainwater drainage downpipe near that corner. No sanitary drainage pipe. And we installed a new downpipe to make sure there wont be water spilling out from the underground pipe.

2) We understand that upgrading the drainage system can help (There is an old AG drainage system alongside the house).

3) We regraded the side aisle of the house to make sure the water can flow away from that corner. But things only improved a little.

Isnt the first thing we need to do is directly addressing the problem : the leaking slab? 

We watched youtube and some companies applied the liquid rubber to the sides of the concrete slab, like this:

It seems much more effective and on point? If there are some "hairline" crack around the corner of the slab, put something to seal them seems to make more sense.

So complicated.
https://construemax.com/leaking-slab-foundation/
One useful link we found about this problem.

What are the most affordable way to solve this? Thank you in advance for any advice.

Any experienced members are specialized in this kind of issues? Really love to hear you thought. Thanks

[deluxe]

Check for any pipes with water then silicon it for 24 hours. Needs to be seen.

[MitchellMc]

Welcome to the Bunnings Workshop community @deluxe. It's great to have you join us, and many thanks for jumping into the discussion.

I trust @ivanptr appreciates your contribution. You might like to provide some more details surrounding the pipes to be silicone and the method you're suggesting.

We can't wait to hear all about your projects and plans around the house and garden. Please feel free to reach out anytime you need assistance or have something to share.

Mitchell

[deluxe]

Who ever did that didn't put any water proof firbre glass. Updated then Simply. Call a roofer to replace the repairs simple.