Loose deck planks advice

Got a couple of deck planks 'swimming'.
Is there a good step-by-step tutorial for repairs somewhere?
Total greenhorn over here, any advice welcome.

Assuming that this is an older trawler with the teak screwed to the fiberglass deck underneath, you will see bung plugs every 6" or so that cover the screws. If so and the following doesn't begin to address wet core that probably exists under the loose planks:

With a small chisel pry off the bung plug and scrape out debris. You should see a screw. Unscrew all in the loose plank. You should now be able to pull up the loose plank. Then squirt some epoxy in the screw holes. After it has cured, drill for the screws (but not too deep), put the plank down and screw it in place.

Replace with new bung plugs. Then use black polysulfide caulk for the joint.

But like i said above, with planks loose you almost certainly have water that has penetrated the core and has rotted it. That is a whole different kettle of fish to fix.

David

Teak is fake. Just for appearance, covering boards. They cost a bundle of cash and ruin the underlying structure. Often they don't even look so good, look dirty, lots of maintenance costs to keep up appearances. They slowly wear away eroding.

Lots of older boats show their age with the worn teak..

If the boards are loose, the screws are no longer holding them down. The broken 1/2 of the screw is still stuck in the fiberglass and probably isn't letting any water into the core. Pull the loose planks up (carefully), clean them up (I use a planer) and re-bed them. If you could pull out the old screw base - great! If not just drill next to it. The new screw will find the new path. With all the deck caulking it won't leak either. Be sure to use masking tape on the deck seams or you'll be sanding caulking for an eternity.

Ignore these lummoxes, teak decks are beautiful. Even grey and dirty.

Teak Taiwanese Trawler decks class 101:

Typically, the Teak is glued down / bedded in black polysulphide sealant. Since, when installing the Teak with the sealant, the boards will decline to stay where they're intended until the sealant cures, it's necessary to screw 'em down to the substrate and conceal the screws with bungs. It's the screw holes which can eventually leak and allow water to penetrate into the substrate. The substrate on these TTs is fiberglass reinforced plastic (FRP) over wood core over another layer of FRP. The wood is often end-grain Balsa blocks but is occasionally any old scrap plywood from the shop floor. The Teak was about 3/8" thick when new and the substrate is about 1" thick total. It does not take long for wet wood to rot, but it can take years before the screws and other penetrations leak enough to cause problems.

I suggest, for your repair, that you remove the loose boards, investigate the state of the screw holes and the core, and you'll learn how much trouble you're in. If you're lucky, there is not much water and rot in the core. A little drilling out of screw bores to add in epoxy filler and gluing the Teak back down with polysulphide. Weight the boards until the sealant cures and use no screws.

If you're unlucky, as might be expected by your description of loose boards, you'll be in for a larger repair. Repairs over large areas might be wholesale removal of areas of the Teak, removal of the top layer of FRP, removal of wet and rotted core, installing new core, installing new FRP, and the final decision is whether to reinstall Teak or fake Teak or some finish which includes non-skid.

Others will surely opine that polysulphide won't hold the Teak down. It will; my lazarette hatch was done that way 33 years ago (see my album showing my repair to the rotted substrate w/o relaying the Teak). Others may opine that the failed sealant lines between the Teak boards cause leaks; I don't think so; loose screws cause leaks. Water under the Teak where the sealant/adhesive has failed surely aids water to get to the screws.

There are all sorts of experiences to be had with Teak decks applied to FRP substrate. Well applied quality Teak will obviously do better than lesser Teak thrown down by a poor crew. I once walked the deck of a Choey Lee sailboat where every plank was cupped upwards; our Teak decks are worn thin but none are loose and most bungs remain.

Many thanks all - this is great advice and feeds my initial learning curve well.
I will get at it when time and circumstances/weather permit and report back with findings and results.

Talk to a pro, maybe get an estimate for a pro job, and find out how they do it.
I did this, thinking I would add teak on top of the cabins. I found out how they do it without using any screws. A better look and no possibility of leaks.
Too $pendy for me, but I still long for the low maintenance of the teak on those upper surfaces.

Thanks bunches

If you have rotted core in your decks there are other signs to look for. Can you get to the underside of the decks inside the boat anywhere? Rotted balsa/luan turns black, you can see it through the glass sometimes.

Drill a little hole on the underside, if water weeps out...

If you find rot you have a decision to make, if you're handy and can work under cover it's fixable - I know, I recored mine. The cost/effort will not be recouped when you sell it.

If you're up north and don't store in heated sooner or later the freeze is going to start cracking things and the water will start leaking in, usually over the Admirals bunk [emoji79]

If you decide to fix PM me I have tons of pictures and advice.