I made a stupid mistake on the improvement project I’m currenting working on. I’m bumping our laundry room out into the garage by 4 feet or so. There is an existing stairs & platform built in order to enter the house from the garage, which I’m extending to become part of the laundry room as well. Well, stupid me neglected to put a level on the surface of the plywood platform to see if it was level. I have built the floor joist system for the new area that marries up to the existing platform. I’ve uploaded a photo of the problem to the Photos section in an album named Shane White.

As you can see, the plywood on the platform slopes upwards, whilst the new joist area is perfectly level. Unfortunately, I’ve nailed the sills of the platform structure into the concrete, as well as nailing the new walls into the platform, so tearing it out would be difficult to say the least. Anyone have any suggestions on how to tackle this?

It’s the existing platform that’s that un-level? That’s 2×6 lumber? I would probably pull up the plywood and shave off the sticking-up portion of the platform (with a sawsall), put the plywood back down. Maybe put a little reinforcement under the existing platform if it needs it.

How about a sawzall with a long blade to cut existing nails into between joists/walls/or studs? This would allow shifting of the off level unit into a level position?

To fix it right you will have to remove or cut the nails/screws of anything you have attached to the platform. The platform probably has supports under the garage side. They will have to be shortened to level the platform. Or if you can raise the floor in the whole room, use floor leveler to level the platform floor then put 3/4 subfloor over that. Another option would be to pull up the subfloor on the platform and start shimming there (probably even more work than option 1)