Sunroom: rotting subfloor
I have an all aluminum sunroom and noticed some leaking. Apparently it has been occurring for some time because the subfloor was mush under the vinyl sheet flooring. I peeled the floor back and the subfloor is indeed mush. It affects about a 1.5x1.5 foot area in the corner. My first priority is to find the leak and stop it. My question is How difficult will it be to replace the subfloor (it actually appears to be two 3/4" pieces of plywood)? The rotten part is in a far corner. Does the aluminum framed wall rest directly on the subfloor? If so, can I simply remove and replace the plywood underneath it? Are we talking about a DIY no-no?