Joist Spacing
- Thread starter russellsmiler
- Start date
Right ok have had a total rethink on this.
Have decided to turn joists 90 degrees so that the total span is 3800mm
I will have one truss bolted to wall and use joist hangers, the other end will bear on new blockwork, total span will be reduced by 50mm to 3750mm.
I have inherited as leftovers a couple of hundred 44mm x 44mm square stair spindles that i will use extensively as herringbone noggings, (or perhaps sell them and use 50mm x 50mm of the shelf).
the joists I have were previously used as joists in a property that we demolished, there is no grading but they were in a structural situation, there possibbly 100 YO when wood was wood, there clean dry and i have rucks of them. they are 48mm x230mm in section. Now I have said i would like to cut the, down to 178mm x 48mm purposly to keep a flush ceiling with the existing room which now becomes extended into the extension.
Yes i could use these joists in there entirety, and batten/pack existing joists, but i really dont want to lose any height in ceiling. the ceiling is at 2400mm which is pretty standard, but the room is going to be quite large, and I know that ceiling height will make all the difference.
My question I suppose is given a 3750mm bearing, and as many noggings as I like + spacing the joists as close as nessessary, what is the minimum depth i can use.
I have looked at Local authority joist/span tables, but they are not in the fine increments i seek.
Again thanks for any advice,
Russell
Have decided to turn joists 90 degrees so that the total span is 3800mm
I will have one truss bolted to wall and use joist hangers, the other end will bear on new blockwork, total span will be reduced by 50mm to 3750mm.
I have inherited as leftovers a couple of hundred 44mm x 44mm square stair spindles that i will use extensively as herringbone noggings, (or perhaps sell them and use 50mm x 50mm of the shelf).
the joists I have were previously used as joists in a property that we demolished, there is no grading but they were in a structural situation, there possibbly 100 YO when wood was wood, there clean dry and i have rucks of them. they are 48mm x230mm in section. Now I have said i would like to cut the, down to 178mm x 48mm purposly to keep a flush ceiling with the existing room which now becomes extended into the extension.
Yes i could use these joists in there entirety, and batten/pack existing joists, but i really dont want to lose any height in ceiling. the ceiling is at 2400mm which is pretty standard, but the room is going to be quite large, and I know that ceiling height will make all the difference.
My question I suppose is given a 3750mm bearing, and as many noggings as I like + spacing the joists as close as nessessary, what is the minimum depth i can use.
I have looked at Local authority joist/span tables, but they are not in the fine increments i seek.
Again thanks for any advice,
Russell
M
munchingB
what is under the suspended floor? cant you build a bit of a foundation and support the joists from the middle to lose the deflection?
IIRC it's an upper floor, so that wouldn't be possible.
If you have as you say plenty of them then why ask a question that is impossible to answer, get a load out and build your own floor on the drive you don't need nail anything together, just space them as you decide and keep ripping them down until you get the required bounce.
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