Wet upper deck on Catalina 22 Sport?

[lestersails]

Hi All,
In decomissioning my boat (2016 Catalina 22 Sport) for the winter I noticed something concerning. See the below photos something oozing from the screw heads that hold down the slides for the cabin top door. I removed that grooved plastic strip in which the cabin top door slides. I cleaned the deck surface and the bottom of the slide (was quite moldy) and put a 3M5200 circular bead around the screw holes and reattached the strip with the screws from below. But, when I tightened them down, a small amount of greenish-brown liquid oozed out.
I assume this means I have water and probably rot in the coring material of my upper deck. Assume also that what this means is that I need to get someone to test the deck for water intrusion and based on the assessed extent, start to cut into it and get that rotten coring out?
And what is the coring material for that part of the deck?
Thanks in advance for any help!
Les

 

[Davidasailor26]

You almost certainly do have some amount of rotten wood core there. You could start by tapping the area around the screw to see if it sounds dull and dead from the rot. That and/or a moisture meter could tell you how far it goes. Depending on the extent of the moisture and how structural the area is you can then decide on how aggressive to be going forward.