Load capacity on floor

[pencilcase]

Hello,

I'm looking for advice on the load capacity of a floor which I'm planning to put an aquarium on. The placement is on the upstairs of a bungalow.

When we moved in we upgrade the entire structure, roof, walls, floors as the property was built in the early 1900's.

The floor is made up of:
9 x 2" CLS at 16" centres with plywood sheets
The beams span approx. 8 metres (26ft)
Each end rests on a brick wall however only one is load bearing. (double skin) and currently has the 250KG water storage tank directly above it.

The aquarium is 750mm x 750mm and will run parallel with the beams so the point load will be in a small space.

The aquarium weighs 400KG although 100KG can be located next to the hot water storage, directly on the brick wall. (saltwater tank with a sump)

Can anyone help with the calculations based on the information above?

Thank you in advance.

 

[jeds]

The placement is on the upstairs of a bungalow.

Is that not a contradiction in terms?

Your floor is on the limit now so there's no way it will comply with a 400kg fish tank on it as well. Domestic floors are designed to take a live load of 150kg/m², so you would be taking it nearly 3 times over that limit. That's not to say your floor will collapse - it probably wouldn't - but heavy long term loads cause what is known as creep. In other words when joists are permanently deflected past their limit the fibre structure of the timber eventually takes on the new shape and the joists become permanently deflected. Also, if you take the joists to their limit it allows nothing for anything else. So walking past will cause the floor to bounce and possibly crack brittle finishes. (plaster) So I'd strengthen if I were you.

 

[pencilcase]

Apparently not :

Definition of a Bungalow: "A low house having only one storey or, in some cases, upper rooms set in the roof, typically with dormer windows."

Anyway, I was of the understanding that most floors don't have 9 x 2 but something like 6 x 2 which is standard live load of 150kg

I think it's safe to assume this just isn't possible. It's not going to be feasible to try and reinforce the floor either because that would mean extensive and disruptive work to 2 rooms and 2 hallways. (the upstairs room is spread over these areas).

Out of interest, how would you reinforce it? My understanding is that adding more timber between the existing beams won't really do much in the way of strength because there isn't anything else to take the load. Vertical supports are impossible since the tank is above a hallway.

Thanks for your help.

 

[tony1851]

@ OP; do your 9 x 2s actually span 8m clear (ie with no intermediate wall below)?

 

[pencilcase]

There is a wall at the 5 metre mark (then 3 more metres to the other side of the hallway) but it's not structural as far as I know. However as two hallways are connected the beams are not supported by any intermediate wall where the aquarium would be placed. (and it can't be placed elsewhere due to the eaves.

 

[jeds]

Anyway, I was of the understanding that most floors don't have 9 x 2 but something like 6 x 2 which is standard live load of 150kg

A typical floor joist would be 8 x 2 over a span of something like 4.5m - not 8m.

 

[jeds]

There is a wall at the 5 metre mark (then 3 more metres to the other side of the hallway) but it's not structural as far as I know. However as two hallways are connected the beams are not supported by any intermediate wall where the aquarium would be placed. (and it can't be placed elsewhere due to the eaves.

Can you increase the load capacity of the wall - maybe with a timber pier or something?

 

[pencilcase]

There is a wall at the 5 metre mark (then 3 more metres to the other side of the hallway) but it's not structural as far as I know. However as two hallways are connected the beams are not supported by any intermediate wall where the aquarium would be placed. (and it can't be placed elsewhere due to the eaves.

Can you increase the load capacity of the wall - maybe with a timber pier or something?

Unfortunately not. The staircase is perpendicular to the wall so access is near impossible. The other side of the staircase is a bedroom and above both is a closed in space which would limit the piece of timber size.

 

[jeds]

So the floor joists aren't spanning 8 clear metres, they span 3m one side of the partition and 5m the other? If so the partition is bound to be giving some bearing. It might be enough?

If not would you want to go as far as upgrading the wall. Remove plasterboard, glue and screw 9mm ply either side re-plasterboard. The wall then becomes a load bearing beam. I presume it's sat on a concrete slab, which ideally would be thickened under the partition. But if not the load will be spread over such a distance it would be minor by the time it gets to the slab. Of course it depends how far you want to go?

 

[pencilcase]

They span 5m (room length) then there is another 3m span that makes up the hallway width...

I don't think it will be a good idea after many considerations and I'm looking at placing it in an alternative room on the ground floor which as you rightly said is concrete.

Thanks everyone for the advice.