Hi brickeyee, you wrote that "winter installed floors are not laid all that tight" Are you saying that professional installers (meaning installers worthy of the word "professional"), would know not to lay the boards tight in the winter and allow for summer expansion? I'm asking because my kitchen floor is experiencing cupping similar to the original poster's description. I'm in MA, and our kitchen wood floor (3/4" Somerset hardwood, tongue and groove) was installed at the end of January. The wood itself had been sitting in a room adjacent to the kitchen for a month prior to installation. The installers definitely put the boards in tight at that time (I could see that). Now in the summer, with weeks of humid weather, the floor boards are cupping. No buckling, but I am wondering about the long term consequences, as I simply have no knowledge of this area. The basement is humid at this time of year, but none of the 100 year old floor boards in the other rooms over the basement are cupping. Yes, they do have slight gaps between the boards--that is part of their character. But only the new flooring in the kitchen is cupping. Should the installers have known not to install the boards so tight together in January? They are local residents of MA, so they know it gets humid in the summer. And (of course) no one asked me whether I wanted the boards to go in tight, and would I have minded if there were gaps to allow for summertime expansion. Thanks! Lee

2nd discussion this afternoon in London was your oak floor. First I think the best thing to do is explain something....In days gone by wood was harvested and then lay to 'season' for no less than 7 years. The reason for this was simple any expansion of the wood would occur in this time and eventually it would 'rest'. However today this is not the case....the wood is put through a kilning process for speed and commercial reasons. We had a long long discussion about this, and the first thing I have to ask is this....did you not do a test area before undertaking the task of re-colouring? I have to advise any client a test area is always a pre-requisite for undertaking any changes to oak. Unfortunately unbeknown to yourself you changed the conditions that this wood was enjoying and it has reacted in this way. This wood was happy and settled before the process of re-colouring was undertaken. The environmental forces of chemicals being enforced upon it now have changed and wood being a natural substance will react to such changes. This is what has happened to your oak. Now the bad news, we have never seen a wooden floor that has cupped be rectified. My advice to you is to see professional wood mason or master carpenter immediately. I am sending my best regards to you and please keep us updated. Kind Regards Lynn (and the boys in London England)

If it is cupping, it looks pretty slight to me. Cupping--unless it's evident shortly after installation--is usually the result of moisture imbalances which are due to environmental conditions outside the contractor's control. Cupping is more evident the wider the flooring width which is why I recommend engineered hardwood for widths greater than 3" As a point of calibration, the performance standard published in NAHB's Residential Construction Performance Guidelines for Professional Builders and Remodelers is: "Cupping or crowning in hardwood floor boards will not exceed 1 /16 inch in height in a 3-inch maximum span measured perpendicular to the long axis of the board. Cupping or crowning appearing after installation may result from fluctuations in the moisture conditions in the house, causing a noticeable curvature in the face of the floor boards. Cupping or crowning caused by exposure to moisture beyond the contractor’s control is not the contractor’s responsibility." If the OP wants to minimize cupping, they'll need to control the relative humidity in the living space as well as the space below the floor. If it's a basement or crawl space, moisture controls need to be in place and some amount of conditioning may be required.

Laying the new floor in the same direction as the old floor is not the normal way to go about this. In the building industry, it is more common to see layers that are staggered or "bricked". In other words if layer #1 is laid in a North-South direction, then layer #2 (the top layer) is laid perpendicular to it in an East-West presentation. If you want to run the new flooring in the same direction as the old, you will want to use some underlayment (plywood) over top of the old floor so that you can maintain the "staggered" or "bricked" layering system. That is one way to maintain the North-South presentation. Please work with hardwood flooring professionals who have some experience renovating these old gems. They will have seen what worked....and what didn't. Their experience will be invaluable on a project like yours.