Recently extended our house and due to needing to move the family back in, I was laying the solid oak floor just a couple of days before. Unfortunatly it didn't stand long enough in the environment which may have added to the issue.
Problem is that in one area I have a joint that has opened up as the boards have shunk. Generally I nailed the board down but in this area I just glued due to have all the central heating pipe running just underneath. The joint has opened up the width of the tongue which doesn't look great.
What can I do. If I fill it then what will happen in the summer as I understand the floor will expand. Any idea by how much? I have tried putting some straps on to pull it back together but know joy. Rooms measure about 2m across and gap right down the middle.