Anyone come across a wall filled with sand?

[Resu]

I think that you are referring to paramount walls. You saying about egg boxes in the music classrooms at my Upper school they had like cardboard large egg box trays stuck to the walls.

No I mean actual used egg boxes! Will try and get a picture on next visit.

As promised!

 

[Percyprod]

No point boarding over the egg boxes, the idea is to leave them ecposed to absorb the sound and stop echos asnin an anechoic chamber. Sand in walls is to make them sound proof. Once worked in a mansion, floors were 10 x 1.25 boards wth steel tongues, had a false floor under, top 3 inches filled with sand.