How much weight can bedroom floor take

jackspade

I spent alot of time researching this question, "how much weight can upper/raised timber joist floor take" ?
The only answers I could find was that ( and in-line with UK building regulations )  the floors should be designed to take a load of 150kg/m2 spread over the entire floor.  
However this is an unsatisfactory answer , because does it mean 2 x 100kg people standing next to each will cause the floor to fail? Clearly not, so the specification of 150kg/m2 spread over the floor is not a useful metric in my opinion.

Ideally I need to know the maximum allowable weight  over a square meter taken at mid span.

The internet was generally very poor at answering this question.

theonlywayisup

Do you need to know the weight your floor will take?  

Belenus

What are you planning to put in that square meter at mid span?

Most upper floor timber and joist floors can take far more weight than they are ever likely to experience in normal use.

Have you ever been to a party where thirty or more people are crammed into an upstairs room dancing away. The floor may shake a bit but it doesn't normally collapse.

sgun

Belenus said:

Have you ever been to a party where thirty or more people are crammed into an upstairs room dancing away. The floor may shake a bit but it doesn't normally collapse.

Ahh ...those were the days. Roll on 2022.

DevilDamo

jackspade said:

Ideally I need to know the maximum allowable weight  over a square meter taken at mid span.

Nobody here can answer that as you’re missing vital parts of information, i.e. joist sizes, spacings, bearing details, etc... Once you have that, speak to a structural engineer. 

jackspade

DevilDamo said:

jackspade said:

Ideally I need to know the maximum allowable weight  over a square meter taken at mid span.

Nobody here can answer that as you’re missing vital parts of information, i.e. joist sizes, spacings, bearing details, etc... Once you have that, speak to a structural engineer. 

im guessing but im expecting my joists to be either 47x170 or 47x195  , probably 400mm spacing and about 3.5 meter span.

I havent pulled up any floorboards to check the joists but judging by the large central beam running through the house and the approx height between lower floor ceiling and upper floor those numbers are accurate

tbh it shouldnt matter what those individual numbers are, the rules state the floor must take 150kg/m2 over whole space and that is all that is stipulated in the building regulations

my room is about 10m2 so in theory should take 1500kg over whole room, but if I put that weight in same area floor would collapse most likely.

GDB2222

Why not bung the joist sizes into a calculator, and do the arithmetic.
"does it mean 2 x 100kg people standing next to each will cause the floor to fail?" It not only doesn't mean that, it doesn't say that. 

If your room is 10 sqm, the floor needs to be able to take as a minimum 1500 Kg, reasonably evenly distributed. That's plenty for most purposes. I don't think the design specs say anything about what happens if you stick the 1500kg right in the middle of the span. 

Norman_Castle

jackspade said:

my room is about 10m2 so in theory should take 1500kg over whole room, but if I put that weight in same area floor would collapse most likely.

The 1500kg in a single square meter would be far above specifications. At 400mm spacing it would only be directly supported by two joists.

greatcrested

,...........

theonlywayisup

jackspade said:

DevilDamo said:

jackspade said:

Ideally I need to know the maximum allowable weight  over a square meter taken at mid span.

Nobody here can answer that as you’re missing vital parts of information, i.e. joist sizes, spacings, bearing details, etc... Once you have that, speak to a structural engineer. 

im guessing but im expecting my joists to be either 47x170 or 47x195  , probably 400mm spacing and about 3.5 meter span.

I havent pulled up any floorboards to check the joists but judging by the large central beam running through the house and the approx height between lower floor ceiling and upper floor those numbers are accurate

tbh it shouldnt matter what those individual numbers are, the rules state the floor must take 150kg/m2 over whole space and that is all that is stipulated in the building regulations

my room is about 10m2 so in theory should take 1500kg over whole room, but if I put that weight in same area floor would collapse most likely.

If you are looking for a specific limit to the span/joists in your house then you need to work out what you have.  There are more tables on joist span than hot dinners.  If it's just a random spec then BR will give you the 'current' spec.  Either way, what is it you are trying to do/prove?

TELLIT01

jackspade said:

tbh it shouldnt matter what those individual numbers are, the rules state the floor must take 150kg/m2 over whole space and that is all that is stipulated in the building regulations

my room is about 10m2 so in theory should take 1500kg over whole room, but if I put that weight in same area floor would collapse most likely.

So why bother asking the question if you already believe you know the answer.