Optimized cutting length help needed

[mr63249]

Is there a formula to calculate this

I need to know how many furring channels, and what cuts I should make to optimize wastage.
The room is 3.63 meters (length) x 4.1 meters (width)
The channels only come in 6 meter lengths so if i cut each length at 3.63 meters I have wasted 2.37 meters
The spacing for the width would be at .6 meters so I think i need 7 lengths at 3.63 meters

My rough guess is if I cut the 6 meter lengths at 1.2 metres

A formula would be much easier to work these problems out for future rooms


I would like to avoid as much wastage as possible

[Pete_UK]

What is a furring channel ?

Pete

[jhren]

At a loss here. I've been involved in construction a fair portion of my 55 (and counting !) years... just not used to meters, or metres, as a unit of measure. Anyway... if cutting 6m lengths to 3.63m is wasting 2.37m, how would cutting 1.2m lengths not be wasting everything you cut???

Typical furring runs perpendicular to the structural framework, which is at a spacing interval. On the surface, it appears the shortest usable length would be the same as that spacing. However, beecause the structural supports' (joist, truss, rafter, etc.) spacing is usually based on the entire structure and not individual rooms, you don't always have a structural support at the parallel walls (in square to structure framing). A non-structural-bearing support is usually added to complete the room's framework... could be one side, both, or neither. Point is, sometimes the span of end furring members could be less than the structural spacing.

That said, when room measure in direction of furring is less than full length of pieces being cut, they must be cut at that length. The remainder section can still be used, but it must match the distance from the end wall to one of the structural members. Not knowing what the spacing to structural member is at either end wall means optimazation cannot be determined... at this time. In most cases of estimating, the room's 'crossing' dimension is rounded up to the next greater multiple of furring spacing because there will always be a furring member at the side walls. The cut dimension is taken at actual, nultiplied by the number of crossing members, then 10 to 15% added for waste. This gives you a raw material estimate. Actuall waste will vary for many circumstances. The optimal cut length is detemine by the max useful length of any piece available to be cut.

Just out of the gate, if your channel spacing is .6m and the crossing width is 4.1m, you will have 4.1÷.6=6.?, rounded up to 7... ×3.63÷6m lengths is 4.25 rounded up is 5 pieces... and already more than 15% extra for waste allowance. For every two full length channels cut to full room dimension, you'll have two leftovers that can be butted together. Since you will have 5 leftovers after full length cuts, you should be good to go with 5 stock length pieces of furring channel...