Beam and block floor strengh for a 500kg fish tank

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Hi all just been pointed to this forum by someone to ask for some help.

Here is the strory,i live in a purpose built council flat thats about 40 yrs old

I live on the first floor i.e there is a tennent below me.

I know the floor is beam and block,i have a 200kg fish tank and im upgrading soon to a 500kg tank,now i think i know which way the beams go (a few builders think same as me) as there is a skim of concrete over the top.

The tank is going to sit on 2 beams against the load baring wall.Now i no noone can say it will be fine thats inpossible not seing the floor,,and im struggling to aford a engineer to come out.

Im just asking for view on if anyone thinks its a defo no no it wont hold or a it will be fine or any other help on it.

im told of 2 council workers it should be fine who did a few jobs,but 1 was a kitchen fitter and the other a chippy,,im a chippt and fit kitchens and strucutual aint my thing so i cant rely on them.

sorry for the long message

thanks
craig
 
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Hi, craig,
I'm a bricky, so you can take that as you wish.
I suppose the 1/2 tonne weight is when the tank is full of water.
Now, if you were living in a modern house with beam and block, and you knew for deffo which way the beams went, then I would just advise you to slip some timbers under the tank right along the floor wall to wall to spread the load and that would be ok. (providing that they spanned all the beams and were next to the wall into which the conker beam ends were built)
However, doing some sums, and subtracting 40 from 2008 leaves me to think that you might be in danger of giving your downstairs neighbour an unexpected shower.
Beam and block then isn't what it is now, I would say, don't do it, buy smaller fish.
 
If you've ever had a few packs of 7N blocks dropped onto a beam and block floor ready for loading out, then you will know that they can take a bit of weight

A timber floor is designed for 1.5 tonne/m2 so I presume a concrete one will take more. Might have to wait for that engineer chap to appear after he's scoffed all his choc-chip biscuits to confirm though
 
thanks for that ive done a very very very rough plan of my flat from the top view.

the flat is about roughly 50ftx25ft and all the sqaures are rooms/bathroom/kitchen etc.in the picture

i might point out that not 1 wall internal is solid or a supporting wall which leaves only external.

my mate recons the beams will not span the long way 50ft and go the short 25ft which i have done in red colour :D

and the blue are the way the false sounded deadening floor runs,(which you would think went opposite to the beam/block)which consist of 3"x2" and 18mm chip bourd sheets on top

the idea was i was going to add more 3"x"2 under the full lengh like already said (ive done them in grey).

sorry pic is rubbish

plan.jpg
 
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Uuuuurp! Pardon me, just finished the last of the packet ;) .

Tank dims? Assuming that they are something like 2mx0.5mx0.5m = 0.5m3 = 500 litres = 500kg = 5kN, then that would give an equivalent load of 5kN/(2x0.5) = 5kN/m2.

Domestic pot and beam floor will be designed for 1.5kN/m2 live load, as Woody says and probably 1.2kN/m2 finishes, with self weight of around 5kN/m2; thus planks at say 500mm centres will be required to take 0.75kN/m live and 0.6kN/m dead and 2.5kN/m self weight along their length.

If your tank is over two beams, that's putting an additional load of 2.5kN/m (although you can take the live loading off, making it a net extra of 1.75kN/m) over part of each beam length. That said, it's - presumably? - going to be against the wall, so the additional bending stresses will be minimal, although the shear stresses will increase somewhat.

If the tank is long and thin, with the long side parallel to the wall (and will presumably extend over more than two beams), you are theoretically still overloading it, but it shouldn't be a problem; if it's more square on only over two beams, you might have a problem, insofar as causing increased deflection and possibly cracking of the ceiling underneath is concerned, but it's unlikely to collapse.

The more that you can spread it over, the better it will be. No surprise there, then.

For a definitive answer, you would need to find out who the pcc floor manufacturer was and ask them to do you a calculation.
 
Hi that has baffled me,,in easy term the tank is to heavy? :D

the tank has a foot print of 3ftx2ft and 26"high plus there is an additional tank under it as a sump/filter,but thats only a tiny thing.

I think the best bet might be to sell the tank and get somethin smaller.

will the floor still be clased as domestic being a purpose built building of flats..id assume so?

I think its going to be spread over more 2 beams,which like you said is putting a lot of weight on it,,with a sofa on the same wall and people sat on it could cause there ceiling to crack :eek:

ive had visions of it going through the floor,,,

got me on choc-biscuits now
 
That comes out as the equivalent of about 9kN/m2 for the footprint, assuming total weight of 500kg. But it is only over a small area.

Spread it over 3 beams, that should be ok, 3' side running parallel with and next to the wall, equates to 6.8kN/m2. Over 4 will reduce it to around 4.1kN/m2, which is even better.

Domestic floor loading of 1.5kN/m2 is the same for a flat, but you're unlikely to get anywhere near that and certainly over the entire floor at the same time, so a bit of extra load in that one area won't hurt.

Sit and watch the fishies and eat some choc-chips :)
 
That comes out as the equivalent of about 9kN/m2 for the footprint, assuming total weight of 500kg. But it is only over a small area.

Spread it over 3 beams, that should be ok, 3' side running parallel with and next to the wall, equates to 6.8kN/m2. Over 4 will reduce it to around 4.1kN/m2, which is even better.

Domestic floor loading of 1.5kN/m2 is the same for a flat, but you're unlikely to get anywhere near that and certainly over the entire floor at the same time, so a bit of extra load in that one area won't hurt.

Sit and watch the fishies and eat some choc-chips :)

Thanks for that,,glad i joined this forum now,,,all i need to do s find that they do run defo that way ,,its so difficult to know where the beams are with the screed stuff over the block and beams..might need to do some digging :D i was also going to bolt the stand at the back to the wall

in the back room a had 2 4ft tanks and 3 2 ft tanks in a room 8x8...which at the time was prob far to much and suppose the load was spread over the entire room
 

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