Damp framing, replace like for like or ?

[AKA-None]

Your comment about sagging was the indicator that it’s structural so that’s what you’ll need to replace it with, something strong enough for that purpose

[Spot]

Originally Posted by AKA-None

Your comment about sagging was the indicator that it’s structural so that’s what you’ll need to replace it with, something strong enough for that purpose

Yes, thanks. I am sort of glad it happened that way, gives me a better idea that the system was built well to start (short of the waterproofing), was mostly intact after the plywood rotted away, and was 100% needed to bear the swing keel as indicated by the sagging that happened after they were removed..

I was introduced to Vectorlam https://vectorply.com/vectorlam-4/ and shown some of the basics by their VP of Engineering. I was surprised to see that the 'good old' material set of CSM+plywood+polyester resin has some admirable properties, especially in compression. I ran this by them and they confirmed it. To make a similar laminate from structural foam and biax requires a greater thickness of foam. It also looks like the 1808 biax+mat and epoxy I have could use a layer of uni to improve the rigidity port to starboard, same axis as current 'sag'.

Still mulling over doing full depth floors or make it as-was with the plywood floor bowed down to the keelson. The deeper floors should be stronger that way but making the keelson a piecemeal operation seems counterproductive. Leaning towards plywood there again too but adding a 1/4" FR4 plate under the nuts and washers. Could split the difference and make the floors straight across on top but in wood deeper towards the hull and saddle the keelson. Still planning on fillets to the hull as well.