On 10 Oct 2005 05:15:01 -0700, wrote:

Is there a recommended way of working out the size of a joist (e.g.
50x150) required to span a 3m distance? It needs to be robust as it
will be supporting a washing machine pretty much on its center point.

One of the walls that the joist will attach to is a conventional brick
wall. To attach to this wall I was planning on cutting a grove with an
angle grinder and then using joist hangers.

At the other end, the wall is soft breeze block - so soft that I can
easily push a screwdriver blade into it. I'm assuming on this side that
I'll need to support it from ground level rather than attaching to the
breeze blocks - The new floor is only going to be about 2ft above an
existing concrete garage floor, so this would be relatively straight
forward as a solution.

Don

The building regs have a load of tables, which tell you the sizes. I
don't have my copy handy, else I'd look for you. The type of wood
effects the size.

If you can support from ground level all the way accross, you can make
dwarf walls to hold the joits, which can now be much smaller.

Rick