A few thoughts on floors & storage

[Shannon Dealy]

I've been overloaded for the last week or so, so this may be to little
to late for Patrick, but here's my two bits.

For a storage building, I just used a few inches of gravel on the floor,
no binders or anything else, anything that I felt a need to protect was
placed on top of pieces of scrap lumber.  I have found over the years that
the biggest hazzard when storing one's belongings is not what they are
sitting on (as long as it's dry), but rather how much the temperature 
and humidity varies in the storage area.  The greater the temperature/
humidity swings, and the more often they occur, the greater the damage 
to anything made of wood, joints separate, solid boards crack, etc.

With regard to piano's on adobe floors or other similar materials, my 
understanding is that you will have some problems.  Floors of this type 
don't do well when a great deal of force is applied to a small area, such
as you get with women's spike heeled shoes, or heavy pianos on three or
four small legs or casters.  Even conventional floors often develop
permanent indentations due to pianos.  I would recommend when placing any
object this heavy on an adobe floor that pieces of plywood be placed under
the legs to spread out the weight distribution, you can make the plywood
look reasonably nice by beveling the edges and applying a finish to it.

The main thing to remember is that while the floor can handle the load,
it can't handle it all in one place.  I noticed in the pysllium thread 
a reference to the effect that if it can handle a loaded dump truck, then
it can handle your furniture, this is not necessarily true.  To give a 
quick and really crudely estimated example:

	Loaded dump truck, 10 tires, gross weight 80,000 pounds,
        ground contact area for each tire appx. 1-1/2 square feet.
        This gives 15 square feet to distribute the weight or
        about 37 pounds per square inch.

	Piano, 300 pounds, four metal casters, contact area one
        square inch for each, giving a total of 75 pounds per
        square inch.

So if your floor material can only handle 50 pounds per square inch,
the piano will sink and the truck won't.  Before anyone feels the need to 
dispute these numbers, I am only giving this as an example of how a piano 
COULD sink when a truck would not.  I am not by any means certain of these
numbers, though I think they are reasonable (I used to work in a truck tire 
shop, and my mother's piano is the basis for the above piano estimate).
        
One additional note about storing goods on any kind of packed earth, 
gravel or similar floor, if the floor is new and does not have 
some type of moisture seal, any flat surface in contact with the floor 
(such as a table top or the bottom of a box) will tend to trap moisture 
migrating up from the ground below, and can suffer damage as a result.


Shannon Dealy
dealy at deatech.com