How to fix plasterboard behind sink that is soggy?

[Cat234]

I was scraping off some mouldy silicon just behind my kitchen sink at the bottom of the tile splashback, when I realised that my Stanley knife was able to easily go right into the wall. It doesn’t seem to be a widespread problem- it stops about five cm either side or that spot . I’m guessing the silicon was so mouldy that it wasn’t sealing that area behind the sink and perhaps has led to water damage to the plasterboard? I’m assuming I’ll need to take some of the tiles off to have a proper look. 

I iust wanted to make sure I’m not missing something obvious- such as- there wouldn’t be any other reason to have a gap behind the sink? The tap is mounted on the counter top with the piping belong the sink so there would be no reason to have a gap  in behind the sink for that. 

Thanks in advance for any tips!

[MitchellMc]

Hi @Cat234,

If this is directly behind the sink, it sounds like the silicone was compromised and allowed water to penetrate the plasterboard. If that is the case, then simply replacing the silicone would likely resolve the situation, and provided the plasterboard wasn't structurally compromised, it'll dry out on its own. However, if this is a leak from the plumping work, then further investigation is needed. If you take a look at the area from under the bench, are there any signs of water damage to the wall, bench or cabinetry?

To answer your question, there would be no reason to have a gap behind the sink.

You might like to post some images of the area so our members can better understand the layout.

Please let me know if you have any questions.

Mitchell

[Cat234]

Thanks very much!