Hello,

I am installing a 3/4" Oak Prefinished Floor in my living room. It is about 12'x20'. I am running the boards along the 12' length to stay perpendicular to the joists and the match the run of the dining room.

Before I started I took out the trim, and undercut the door jambs. I placed all the threshholds, which are basically boards run perpendicular on the sides (stapled on tongue and glued) on the left (kitchen) and right (mudroom), a oak stair tread on the step down to the new dinning room addition (face nailed and glued) (front), and a single board run inline with the row direction on the one bedroom (rear).

My plan was to run the board side tongues into the kitchen threshhold (left), and butted up against the mudroom door frame (old exterior door frame) (right) and the rear threshold piece to the bedroom. I will use reducers then from the board to the other finish floors.

My question is, I can leave enough expansion gaps on the walls, and I'm not too worried about the Kitchen and mudroom doorways as the floor shouldn't expand much on the left and right sides, but the step down in the front and bedroom door at the rear are directly opposite each other across 20', do I need to worry about an expansion gap on these thresholds? I planned to run them tight.

Thanks
Justin

Images:

A threshold will sit on top of the flooring, leaving an expansion gap that will be covered by the threshold. A reducer strip can be used for a floor that is not the same height.. No threshold is usually needed for carpet. The small expansion that will take place will be "absorbed" by the carpet, if that is next door. The "expansion gap" for floors is for the time when the floor gets lots of water and can expand against walls with enough pressure to move the plate, before it starts to buckle up when the nails let loose. When wood gets really wet it can exert tons of pressure. Normal expansion and contraction will usually not be much of a problem. The fasteners will hold the wood in place. If you had a floating floor you would need to cover an expansion gap.

Thank You Sir.