New + Old Floor = Uneven

We just finished having approx. 1000 SF of living space added to our ranch home and wanted to install maple hardwood floors (3/4 " solid 4" planks) in the living room. Problem is where the old part of the living room meets the new we are somewhere between 1/8 and 1/4 " off, the new part of the addition is plywood while the older portion is tongue and groove planks. I figured we could bring up the new floor by adding some 1/4 plywood (nail and screw) but it would then make the new floor a little too high. The uneven area runs the length of the addition in the living room (approx. 18 feet across), the only thing I can think of at this point is to rip up the existing tongue and groove to lay down new plywood, this will be a real hassle because I would need to cut it perfectly to the edge of the sill plates.

Anyone have any suggestions to correct the problem without tearing out my existing T & G? Any suggestions would be appreciated.

Mike

 

Had a similar issue with a new attached garage and 2nd floor addition. The floors at the new 2nd floor door way (french) were off due to the house not being level. They were even at one end and about 3/8ths + at the other. After many ideas we ended up cutting the joist below the old tongue and groove wood floor to bring it down to the level of the new. Had just enough room to get a sawsall with a long blade in. We were able to do this because the "threshold" area had its own plywood that we pulled up. (probably would have cut out anyway to make it happen if we had to) We made sure the studs were level and put in a piece of metal angle (like you use to hang garage door stuff) to act as a guide and cut along it. Have to bend the blade a bit while doing it but the guide gives you something to work against. Probably will have to do the same procedure downstairs between the kitchen and new utility room. More fun.

 

Why not glue down 1/8" plywood and rent a drum sander to sand the T&G flush with the plywood. You shouldn't have to sand much more than about 4' wide to feather the old floor flush to the new and it would be almost imposible to see any difference in your 3/4" flooring. Use 24 grit paper and use 30lb roofing felt as a vapor barrier. Check out the NOFMA site for installation. They even give information for installing over an existing T&G floor.