Washing Machine Weight

[John D v2.0]

Think I'm going to build a solid platform but it's about 4ft deep.
My Plan is as per the attached (pinched from another thread) .. I'm going to build a blockwork wall up to floor height.

Can I backfill this cavity with any old rubble like old bricks etc (removed from the chimney that's being opened up) and then top off with a poured 4 inch concrete slab?

How thick will this blockwork wall be? It will need to hold back the pressure of the rubble you throw in.
Normally you wouldn't make up such a lot of ground level by backfilling.
Personally I'd just hang a couple more joists from the wall to the other side, it's quick to do, easy to diy a doeand sn't need large amounts of material
That's about as far as my thoughts go.

 

[Ian H]

Or a wall on its own to support the joist level with the side of the machine?

 

[FRAN1870]

Ok I’ve slept on it and I’m ****ibly over thinking it.

I’m going to build an osb stud wall structure underneath and fix to the concrete floor (with damp membrane to protect the timber, although it’s not a damp floor)

Then whack a layer of rockwool under that area to dampen the sound?