Load bearing question

[ss]

Can anyone help with this load bearing question.

I initially want to place a weight that will have an area of 55 x 48 cms and currently weighs 90 kilo.

The floor that this rests on I have no idea what it is and cannot access it to be sure, however the floors in other parts of the house are I believe ¾ inch proper floor boards (not chipboard), I cannot be sure where the weight is going is constructed the same as it was a later addition to the house (around the 80s)

The room this weight is going in is approx 6 x 3 feet and I have no idea of the state or number of the joists or indeed what direction they go in.

So assuming the worst, if the floor is chipboard and the joist are running the 6 ft length what would be a rough guide to the maximum weight that could be placed on this floor as I am looking to increase the weight by another 70 kilo giving a total of 160 kilos.(same floor area)

[Andy Burns]

My feet have an area of 35 x 26 cms and I weigh in at 157 kilos

Even with jumping up and down, I've never gone through anyone's floor (chipboard or wooden boards)

HTH :-)

[newshound]

Someone will be along in a minute with the official numbers, but your first case is clearly less than a large person standing upright with his feet together, while the second is another smaller person standing very close to the first.

So superficially, I can't see that you are going anywhere outside normal loadings.

[Tim+]

Hmm, 160kg. So, two fattish people cuddling. Can't see that stressing most floors too much.

Tim

[ss]

Duh! I should have thought that through a bit more as it becomes obvious when you compare it to people, I was nearly asking another about it being a dead weight and will be sitting there for years to come, then I thought thats (90k) about the same a washing machine thats sits for ever in the same spot. I need to reboot my head me thinks.

Thanks guys

[Andy Wade]

Common sense here suggests you don't have too much to worry about, unless the floor is rotten or riddled with woodworm. 160 kg is only the mass of 2 or 3 people and they could stand together (just about) in a similar area without worrying about the floor giving way.

If you want to be more analytical, the usual design floor loading for houses is 1.5 kN/m^2, uniformly distributed. 160 kg (1.6 kN) over your area of about 0.26 m^2 certainly exceeds that (by a factor of ~4) but the rest of the room is presumably lightly loaded. Taken over the whole room area (~1.6 m^2) the loading is ~1.0 kN/m^2 - well within the design value. To analyse the situation in any more detail you really would have to determine the structural details. But 6 ft is a very short joist span, assuming this is at 1st floor level with (say) 175 mm deep joists, and the factor of safety is likely to be huge.

If you're still worried get a structural engineer in.

[Tim Watts]

Thank you - I feel much better now ;-)

[Andy Burns]

Well it *is* hibernation season :-P

[ss]

Thanks Andy, this is just a small unused porch so nothing much else in there as we like to keep the rest of the area free as a fire exit. Quite frankly if the weight fell through the floor it wouldnt cause any disruption to the house.

[Tim Watts]

Yes I have such big feet

;->

Seriously.

I'm joining the gym in January. Yes, cliche, whatever...

But I sit on my a*se all day and like cooking. So roundness is inevitable. I need a couple of structured sessions twice a week to try and restart my metabolism. I really do not feel remotely fit right now.

Although I can still outwalk the kids. One has a slow metabolism and likes being a cat, the other such a high metabolism he literally burns off the food as soon as he eats it. He however has a very low long term energy reserve I guess because he's so thin. Lucky bugger :)

[The Natural Philosopher]

lets face it, 90kg is a bath with 90 litres of water in it. Would you be happy to install such a bath?

I myself weigh nearly 85kg, and so too do you. Probably. Its 13 1/2 stone.

Does the floor flex when you stand on it?

90kg is nothing. 900kg is staring to be 'heavy'

[F Murtz]

Which in some cases have 4 small feet, so with Andy in it as well, 250 kg per a few square inches of feet area.

[ss]

Nope no flexing.

[Dave Liquorice]

I think that is more likely to be a problem, rather than it crashing through the floor as you install it.

Can you really not see which way the joists run and where? Are the boards secret nailed? Lines of nail/screw heads are a bit of a giveaway...

The final weight of 150 kg I'd be happier spread across at least couple of joists. Our 300 l (so >300 kg) thermal store is on a low platform (frame of 3 x 2's, 3" upright, 3/4" ply top) to spread it's weight over at least four joists but probably 5 joists. As advised by a structural engineer.

90 kg i'd say is double the weight of a washing machine. They are heavy but at 90 kg they would be a real struggle to move on ones own.

[JimK]

/90 kg i'd say is double the weight of a washing machine. They are heavy but at 90 kg they would be a real struggle to move on ones own. /q

Miele's base model is 94kg......

Jim K

[ss]

The previous owners have tiled the floor thats why I cant determine whats underneath.

[Johny B Good]

Do you really mean kilogrammes? That's just over 24 1/2 stone.

Now, I _am_ beginning to think you _must_ have meant 157 Lbs after all (11 stone 3 Lbs).

[Bill Wright]

We had a kid like that. She was a problem in cold weather because if she got cold (and it happened quickly) she became very peculiar indeed. A hot drink and a duvet fixed her quick though. She's grown up to become a marathon runner and lawyer.

Bill

[Andy Burns]

Indeed I do, every few years it creeps up on me ...

[PeterC]

That's because you weight for it.