Flooring problems

[eylandter]

I am currently owner building a house in the rainforest of a Cairns suburb. I had a builder work with me on this project and in the middle of December last year we laid a Blackbutt 80mmx 19mm timber floor. We laid the floor out in 4 seperate piles for about a week to accliamatise the timber to the tropics. The floor was then glued and secret nail to the joists allowing a 12 mm gap around the walls. The humidity in Cairns for December was on average 60% as per the bureaus website. In January we had substantial rain with average humidity of 78%. Thats when all our troubles started. The boards have pushed walls 30mm off the joists, (this is additional to the 12mm gap left next to the wall) and the boards have increased in size at least 1mm in width. In one case the boards have lifted 120mm off the top of the joist. We had the boards tested last week for moisture content and they currently measure 17%. The timber supplier indicates the boards left the mill with between 12-15%. The boards are still growing. Any help or suggestions gladly recieved.

[Gaza]

och....

cut out a few boards in each room and wait till the floor stops moving then replace with a new board and allow room for expansion.

being in wet area i would have left 2mm gap every 6 boards plus 20mm at vertical surfaces.

[eylandter]

Thanks Gaza for your reply. As most of the boards have now broken the glue and lifted about a minimum of 2mm in most places, two large areas of flooring will need to be replaced (approx 4x 3.6 and 3x3m) as these boards have lifted between 5 and 20mm and with the secret nails can't be knocked down as the staple bends over. If i was to face nail the boards that are retrievable how much will they contract in the dry season? Do you think that the boards could have been dried too quickly? Will they keep increasing in size with the wet season still around and increase in moisture content. We spoke to our neighbours on both sides and they have had no trouble with their floor?