floor joist spacing?

[yar1950]

I recently asked if stud partition studs of 600mm centres are allowed by building regs wich I was told yes. My new question is: Can floor joists also be spaced at 600 or do they have to be 400?

thanks guys

 

[RonnyRaygun]

I recently asked if stud partition studs of 600mm centres are allowed by building regs wich I was told yes. My new question is: Can floor joists also be spaced at 600 or do they have to be 400?

thanks guys

Yes, they can be as long as they are designed for the additional load that they are carrying.
You may also require thicker floorboards to span the extra distance between the joists.

 

[RogerBoyle]

Yes in general they can be ran at 600 but you have several factors to take into consideration like the Length of span, the final floor covering.
What internal walls are being built on them, loadings etc. to name but a few factors
When this is decided you can do or get some calc's done that will give you a min size timber for the joists and a spacing
Pick the one that suits your requirements the best

 

[chickenlips]

I recently asked if stud partition studs of 600mm centres are allowed by building regs wich I was told yes. My new question is: Can floor joists also be spaced at 600 or do they have to be 400?

thanks guys

Yes they can be, although generally, you will find most traditional joists are specified at 400mm centres, 600mm centres are more commonly used in engineered joists (I joist or open web).

 

[yar1950]

thanks for your help guys. The building is a old Victorian little shop with flat above. The actual room I want to put the joists in is in the flat. The room only has a span of 7ft 6" or 230cm. The original joists are only 6x2 with a few 6x4 and the centres are 400mm. The ceiling in the shop below this area is very low so to get a decent acoustic barrier I am putting new joists in between the old ones on hangers into the two walls. I am putting them about 35mm higher so that the ceiling below and new floor are separate. The new joists are all 6x3, I though that by using 600 centres would be less joists to transfer noise? and also suit the 600mm acoustic boards I will be using.