Expert: Bill-C - 10/25/2007

Question
please help me
i live in a first floor flat in hampshire witch has beam and block flooring with a floating timber floor ontop,
i have recently built a large fish tank which base measure 99"x19", there are smaller tanks within the stand to hold the filteration. this all adds up to 1.25 ton /glass /water ect.
the problem is i have just found out that the tank is running parrelle with  the beams , as in it is only sitting on 1 beam, i know that it should span across many beams to be best affecitve weight distribution, and i really can`t put the tank on another wall as, it just would`nt work in the room i.e tv postion and chairs ect.

i was woundering if i could remove the floating floor and lay either 60mm(height of floating floor) timbers bolted together at 2.4 meters across the beams technicly creating a 6m2 foot witch the tank would sit in the middle of as these would go into the room behind the wall the tank sits against

or i could use 4x 3.25 meter lengths on 60mm steel box section with the same principle

im really stuck and have got so far with my project and don`t want it all ending in tata`s and a trip to a&e
any thoughts sujuestion would be very greatfully received

many many thanks

tony

Answer
Hi Tony,

What you don't say and i presume the floating floor battens are running 90 degrees to the floor beams?
If not , carry this out -- use load bearing timbers ie; red pine and treated so as not to rot with moisture .
Lay the timber battens50mm x  50mm at right angle to the floor beams and span the length of two beams  with a bearing over these by at least 200mm, Lay these at 300mm centres and dwang with short sections between at 450mm centres forming a grid frame,nailing or screwfixing the timber will suffice as the load is transmitting downward compressing vertically.
If you have the height lay and fix structural plywood 10-12mm on top fixing at every 100mm centres with screws or annular ringshank nails. this should be more than  sufficient to transfer the load .Normal houshold load is average to approx 1.5knm2. Just ensure you gradually fill the tank over a  7 day period to allow undulations and compression of the timber to bed in to the sub floor.
Hope this is of assistance to you, and dont hesitate to follow up.
Regard's
Bill