Our 1996 Sundowner 205 DLX definitely has nine lives! We had a transom repair that turned into an engine rebuild and now that the boat is running like it did in 1996. One thing that always bugged me was the floor was sagging. After removing the screws, I pulled up the center floor cover and was met with the ugly blight of wood rot. Yikes.
https://www.dropbox.com/scl/fi/brjsou70ufoupzn1v0k84/FLOOR1.jpg?rlkey=65g4f253opf0e7vgzuj441plk&st=num1v5tt&dl=0I set out to replace the floor support as this was absolutely necessary no matter what I wanted to do next. I measured each of the pieces. The entire framework is installed by screws, so after removing some 16 screws I was able to wrestle the boards out of the cockpit.
https://www.dropbox.com/scl/fi/s74gqo28ssjwby9glumke/FLOOR0.jpg?rlkey=8z9m5g34dtqnb4cn0mdhdhaby&st=002y3n90&dl=0The wood was so badly splintered some of it crumbled in my hands. I can't say what type of wood was used under there, but it was very cheap and hardly seemed marine grade. It looked more like pressed plywood. Just awful. Here's the good news: the rest of the wood under there (along sides of gas tank and walls) was fine. It looked great - nothing to complain about. For my replacement framing I looked into marine grade wood here in Portland but it was ridiculously expensive because I would need custom cuts. The side rails were 1 x 3's, the crossbars were 1 x 2's. You just don't get anything like that off the shelf anywhere. I supposed I could have gone with thicker wood without any issue, but I wanted to keep the replacement sizes the same. With a little research I came upon 5/4x4 primed wood used mostly as trim for houses. They are water resistant and the real-world measurement was 1 x 3.5 inches. They also have a 1 x 2.5 inch length. The extra .5 inches would work under the floor (above the gas tank) with no issue, so I bought two 16' lengths - the only size they sell them. I used the measurements to recreate the rails and slots for the wood crossbars. A bandsaw was used to make the cuts.
https://www.dropbox.com/scl/fi/q0q3emx96h9nl7p4dda99/FLOOR9.jpg?rlkey=fqarh9yz3kvsp9hph55ym4gfz&st=oyuywgzo&dl=0I laid the structure on the garage floor to make sure the cuts were flush.
https://www.dropbox.com/scl/fi/64bul4crx85q9a7bjaymg/FLOOR2.jpg?rlkey=r2nxit36o168vs5kmvmk784o3&st=vhs2txsa&dl=0Next step, assemble the materials on the boat.
https://www.dropbox.com/scl/fi/zt8t3r2kw360egxav6lb1/FLOOR8.jpg?rlkey=y8jfvt1xdvh9gvtjr1ofmcdia&st=g5uwwtpz&dl=0It was pretty easy to line up the top of the first siderail to where the old one used to be. I drilled a couple of new holes through the wood into the wall to support the first side. Note that I had to cut out a piece near the gas hose because the 3.5" length would press up against it and didn't want vibration ro cause any issues.
https://www.dropbox.com/scl/fi/i66xgjdljpi2g539qz3oe/FLOOR3.jpg?rlkey=mwhn3go17rqk9i77979soiqv5&st=i0hpoh37&dl=0Note, too, I treated the open cuts with Copper Green Wood Preservative, just as an added precaution. In fact, I sprayed the Copper Green on the gas tank wood supports as well, knowing full well it probably wouldn't make a difference there - but every little bit helps. The sides and the wood wall at the engine were strong and, after almost 30-years of boating, sturdy. I didn't spray there. Evidently not a lot of water gets into that area of the boat. If it does, it comes from water on the carpet above. Years of kids water skiing, etc. probably did that floor in. Everything lined up perfectly as I screwed in the second support rail and dropped in the crossbars.
https://www.dropbox.com/scl/fi/1c8o5r49dduoj0fbqqeho/FLOOR4.jpg?rlkey=qdsrqc847wtprnbdu659pfbb0&st=ck2mn59i&dl=0I did have to shim one of the crossbars to insure it was flush. It was treated with Copper Green and glued into the slot. But it all came out flush. Each of the crossbars needed to be secured with a screw (that's the way it was assembled at factory).
https://www.dropbox.com/scl/fi/cbd2btsuxftcracl8tjbq/FLOOR5.jpg?rlkey=li5wc75k0853vatu2nyl677vz&st=rx2gsngc&dl=0Once assembled it looked like it should. I thought about adding another crossbar, but that might have been a bit of over-engineering. At this point it was time to put the cover back on and screw down (15 times) the lid. Presto.
https://www.dropbox.com/scl/fi/y8wvfjpiyc8txp5y6q2xs/FLOOR6.jpg?rlkey=hknk81yf92kizx9jocje6y24c&st=h8kcf61w&dl=0It feels solid, like when we first bought it. There's no give on the floor anymore. I would have loved to replace the plywood cover, but finding matching carpet is about impossible. Besides, that plywood was in good shape. (I may treat the underside with Copper Green someday.) If you have any ideas, let me know, Someday I'll replace ALL OF THAT almost-30-year-old carpet...but it works for now.
You are all more resourceful than I - so add your tips and what worked for you. As for me, i am glad this project is over.