WOODWORKING QUIZ for 13 June 04

[Ralph Jones]

Good Evening Friends,
When framing a structure and laying out the joists and studs on 406.4mm and being permitted to layout the rafters/trusses on 609.6mm.

How many or which rafters/trusses land over a stud?

Respectfully,

[Tonz]

Every second truss will fall on every third stud...

Studs 0",16,32,48,64,80,96"....
Trusses 0",24,48,72,96"...


Hey Ralph, as I said on a previous post (which I guess you didn't see) why don't you just say 16" and 24". We know what you mean even if you are using imperial terms. There's not a lot of point in going to the effort of directly converting your imperial question to metric for our benefit if you end up with weirdo numbers.

If it really was metric the studs would be at 400mm centres and the trusses would be at 600mm centres.

[bitingmidge]

Not with your usual thoroughness Tonz, although I agree with your sentiments about the metric stuff.

You see if the building length was not divisible buy either of those two dimensions, and the trusses were set out from the centre, only the end ones would coincide, assuming all the while that the wall has doors and windows which of course interrupt the stud grid...



BTW wouldn't the studs be at 450 centres?

Cheers,

P

[Robert WA]

2nd again. Dammit.
The common length is 8 inches. You have the studs at 2 times 8 inches and the rafters at 3 times 8 inches. Every multiple of 2 rafters (2,4,6 etc) will coincide with a stud.
In building terms we work in multiples of 25 mm or 300 mm, they being the rough equivalents of 1 inch and 1 foot. Typically we might buy an 1800 mm length of 100 mm x 50 mm. What we would get is the same as you would get if you asked for a 6 feet length of 4 x 2. Neiether of us would get exactly what we asked for because the measurements are off saw and the timber/lumber would have shrunk.
Tonz is right, as to his answer and his comment.

[Ralph Jones]

Good Evening Friends,
Every third rafter/ truss would end over a stud as 3 x 16" = 48" or the third rafter/truss.

Thank you for your support and help with the figures.

Respectfully,