Too much weight- floor collapse?

[djmk1988]

I understand this might sound funny to many of you here. Also, it might sound like a joke post but this is as serious as it can get.

If I posted the subject under the wrong category may I ask a moderator to move the thread somewhere else.

I live in a wooden house in Central Cardiff, which is probably dated around the early 1900s. The house floors are made completely out of wood. I do have a quite generous reel to reel collection which I keep in one of the rooms on the first floor. The room measures about 3.50m by 3.80 approximately. Given there are about 30 machines in this room (the rest of them are on the ground floor) I would imagine the weight of them alone plus furniture and also other bits like amplifiers and tapes would rise to somewhere around 1000kg including myself - it does sound exaggerated but it is as real as possible.

May I ask what is the possibility of the floor to collapse under this weight and should I seriously consider moving everything somewhere downstairs?


Cheers to you all.

[Station X]

Difficult to say without knowing the size and spacing of the floor joists and their condition.

It's better to place heavy items close to supported walls rather than in the middle of the floor.

1000kgs is the weight of about 15 people.

[djmk1988]

There's not much stuff really in the middle of the floor.

But I am really getting very paranoid with this especially after reading some pages online with people's floors collapsing. Probably the healthiest solution would be to move everything downstairs for my own peace of mind at least..


I am waiting to see what other people here would suggest,

Thanks for your input though, Graham

[paulsherwin]

If the floor is really near collapsing then you will see the ceiling sagging and cracking in the room below.

That said, you shouldn't store large amounts of heavy industrial kit in domestic premises. They simply aren't specified to take the load. It's very unlikely the ceiling will collapse without warning though.

[djmk1988]

Originally Posted by paulsherwin

It's very unlikely the ceiling will collapse without warning though.

That really is going to block me from having a good sleep from tonight onwards and I'm being honest about it.

[The Philpott]

If practical, remove the heavyweight items from the room and hang a weighted plumbline from the centre of the ceiling to a floorboard below. Adjust the length so that the plumb bob is just touching the floor.
Replace the equipment in the room as normal and see if the floor is deflecting- and by how much. Then all you have to decide is...how much is too much.
It may be labour intensive but it is a solid strategy to start from.

Dave

[G6Tanuki]

The smart thing - if you're really worried - would be for you to engage a suitably-qualified structural engineer/architect - I'm sure RIBA could recommend one - and get him/her to provide a written report/advisory.

Having - by this posting - demonstrated that you have 'concerns' about the issue - if they remain unaddressed and a subsequent failure were to happen, your property-insurers may be disinclined to pay-out. £500 for an architectural/structural report is cheap, all things considered.

[In times-past I witnessed units of a multi-million-pound supercomputer wheeled across a distinctly-incomplete false-floor. There was much wobbling, and quietly-uttered oaths in multiple European languages].

[M0FYA Andy]

Originally Posted by djmk1988

That really is going to block me from having a good sleep from tonight onwards and I'm being honest about it.

If you are so worried about it I really think you have answered your own question.....

Andy

[MotorBikeLes]

David had the correct response as usual. How many joists. What spacing. how wide each one, and how deep.
Not sure offhand the transverse strength of joist timber (i have it somewhere) but you could calculate the floor's strength.
I had an old set of volumes on building construction, and this subject was addressed there. If memory serves, the first regulations regarding flooring timbers came from the LCC (London county council) in about 1902, and slowly updated thereafter and adopted for all areas.
The UK has building regulations, almost certainly available online, which probably include calculation info.
Start off with the numbers and sizes of the timbers.
I have just found a copy of Spon's Practical Builder's Pocket book from 1937, and it has strengths of timbers in there. Probably much more. I will look later.
Les.

[Joe_Lorenz]

Hello everyone,

if it was to think about a new wooden construction such a question would be easy to answer. But now we talk about a proudly aged house, so everything is possible.

In most cases timbers are sound and solid, engineered with caution considering the good possibility of someone placing a piano in the middle of the room and playing Schostakovitch with verve! But the other extremum would be the possibility of water having found a way to intrude the structure followed by rotting wood.

So, I would inspect the house thoroughly and follow Dave's tip. 0,1% Deflection is ok, so for a span of 6 m this would be 6 mm.

And well, Graham 1000 kg = 15 people? Sorry, no, I'm afraid that's not more than 10 people ;-) or maybe 11.

Regards, Joe

[GrimJosef]

All that said, in Edwardian times it wasn't uncommon to have a piano in the house. One of my great-grandfathers was a professional piano-mover (there were enough of them that that was a full-time job in a market town) and he used to say that they were quite often upstairs (and a nuisance to get there - or words to that effect ).

Our local building inspector once told me that modern floor joists are spec'd at least to support bags of cement laid uniformly, one layer thick, covering your whole floor. That may not be much help though if your joists a) were laid before building regs came in or b) have been degraded by time e.g. by having the ends go rotten where they are set into damp external walls or by not-so-professional plumbers and electricians cutting excessive slots and/or boring excessive holes in them.

Cheers,

GJ

[Richard_FM]

I remember my dad reckoned 12 average weight adults were equivalent to an imperial ton when planning the capacity of a bus.

Once he claimed he was an excursion when the bus he was on encountered a weak bridge, and the driver had to ask the passengers to get off and walk across. When empty the bus was just within the weight limit.

[Station X]

Originally Posted by Joe_Lorenz

And well, Graham 1000 kg = 15 people? Sorry, no, I'm afraid that's not more than 10 people ;-) or maybe 11.

Regards, Joe

Rather depends on whether on whether they're men, women or children (most likely a mixture) and how obese they are.

A 100kg man, or as we'd say 15 stone 10 pounds, is quite large.

It would take 11 of me to make a tonne.

[Radio Wrangler]

That it's a wooden house may not be particularly important. Brick and stone houses still have timber joists and floors.

If you have any doubts, you need a professional inspection by a structural engineer. You are not going to feel comfortable otherwise.

I do know someone, one of the horsey gang back in the eighties, who had a lounge floor collapse into the apartment below. It was a newly built private block by a national house builder who used to support TV advertising agencies more firmly than it seems they built floors. She complained that the floor cracked and sagged during her housewarming party. The company pointed her to fine print: I think it was no more than six persons! Almost end of story. She went for the publicity option, got a refund on the flat plus costs. Bad press trumps advertising and legal weasel words.

But in 1900 things were built with a lot more margin. A school friend's house of that period had a slate billiard table in the attic, but only 3/4 size.

If you know the sizes of your joists and their number/spacing, there are stress tables.

David

[Glowing Bits!]

Our house was built in the late 1700's, it has solid oak beams at a spacing of just over a foot, the floorboards are solid wood with woodworm holes, at least 1 inch thick, the contents upstairs will weigh at least half a ton, the ceiling has always had a natural middle sag since we moved here in the mid 90's.
In case curiousity gets the better of you, the floor in the middle, compared to the sides, has a dip of at least 2 inches, it is noticeable when walking from one end to the other.
The floor joists rarely move when bouncing around up there, the floorboards do it instead.
If it puts the OP's mind at ease, a (sadly deceased) mate had an attic full of VHS tapes, many thousands, the ceiling did bow slightly with all the weight, it never collapsed though.

[regenfreak]

The EASA ( European Aviation Air Safety Agency ) estimates that the average male weighs 84.6kg, a female 66.5kg and an under-12, 30.7kg. So 1 metric ton is roughly 11-12 males. I had similar conversation with a mate who wanted to put olympic weights, bars and training cage station in a small bedroom with wooden floor. He was worrying the load concentration at the middle of the floor and the consequence of his landlord finding it out!!!!

[G3VKM_Roger]

Originally Posted by Richard_FM

I remember my dad reckoned 12 average weight adults were equivalent to an imperial ton when planning the capacity of a bus.

Once he claimed he was an excursion when the bus he was on encountered a weak bridge, and the driver had to ask the passengers to get off and walk across. When empty the bus was just within the weight limit.

Well, taking my weight today at 85kg about 12 of me would equal approx 1000kg (11.76!). As regards the bridge story I'm told that the former lifting road bridge near my village (on the A143) used to have a weight limit which necessitated passengers having to de-bus and re-bus when crossing the New Cut canal.

But getting back to storing heavy equipment in old houses, I recall visiting a 1930s style house in Kent to collect some Larkspur radios from a Silent Key sale and being asked by two amateurs who were dealing with the estate to help lift down several AR-77 and AR88 receivers from the loft, which we did with ropes, IIRC. For several minutes after lowering the receivers there were audible creaks and groans from the loft, which I found very off-putting! After the noises stopped the lady of the house found that she could open the door to an airing cupboard upstairs, which had not been accessible for many years!

I have a lot of radio stuff in my loft but it's ex-aircraft gear mostly, so light in weight and is dispersed on shelves fastened to the breeze block inner walls.

Cheers

Roger

[Glowing Bits!]

Maybe the airing cupboard door was holding up the ceiling?
Just a thought.

[petervk2mlg]

If we don't hear from djmk1988 again, we'll know what's happened.

[Electronpusher0]

Might be worth contacting the Weald and Downland living museum just north of Chichester, they have a lot of expertise in wooden buildings, they even run courses on strengthening old buildings.
https://www.wealddown.co.uk/

Peter