Another illustration of
using the water level
If you haven't read the
basic water level explanation
you need to read this first
My task is to level a 20' long ledger board
for the deck. From your
drawing, it looks like I would take two 10+ foot tubes, insert one end
of both tubes into a bucket of water.
There's only one 20 foot tube
(mine's more like 25'-30'). The dashed line is not a second tube.
It symbolizes putting the tube in a second location.
Then, I would siphon (i.e. pretend like the
tube is a straw and draw the
water up to my mouth) each tube?
Yes, I suck water into
the tube, If you do it just right, once water has come up and over
the edge of the bucket and back down the outside you can lay the tube
near ground level and it will fill itself. It doesn't matter how
you fill the tube, just be sure there are no bubbles large enough to
break the continuous run of water.
Second Illustration Will Help
Make sure the bucket is sitting on something such that the
surface of the water in the bucket is roughly at the height of the ledger board ( can be off several inches ). Put one end of the tube in the bucket and make sure it stays submerged.
Fill the tube with water. Get a stick (I normally use a yard
stick) and attach/tie/tape the stick to the tube such that the
water level in the tube falls
is near the middle of the stick.
Hold the stick up to one end of the ledger. Mark the top of the ledger on the stick or tube
Without moving the stick, also mark the water
line mark). Remember
which mark is the water line mark and which is the ledger mark,
maybe mark them with different colors. Move to the other end of
the ledger. Move the stick up and down until the
water level in the
tube lines up with the water line mark. The ledger should line up with the
The stick isn't absolutely necessary;
you can make your marks on the tube. But, the stick it makes it easier to handle the
tube and keep it reasonably straight and vertical. Also, if you intend to
reuse the tube you can replace the stick.