wrote in message
ups.com...
My husband and I want to build a concrete wall (and finish it with
stucco) on the windy side of a concrete slab which we intend to make a
patio. The wall will be 20' in length by ~5 ft tall. Have a number of
questions to which we could not find answers on the web or in
literatu
- do we need rebar in a 5 ft high wall?
- how do we attach the wall to the house?
- can we just start laying block on the slab or do we need to put some
kind of footing in?


Whoa, what are you doing here? You say a concrete wall, then you say you
are laying block. One or the other. Is it poured concrete (that does need
rebar) or is it concrete block? Big difference in construction.

In any case, you need a footer. Depth of footer is dependent on climate and
soil conditions and can range fro 12" to 60". Call your local building
official to be sure.


- the cement slab has a crack in it cause by a tree root nearby (we
think), will this cause the wall to shift or crack, could we span the
crack by say laying every other block on the bottom row?

You are asking for trouble. Find the problem, fix it, then start over, even
if it means taking up the slab.

- we live in central WA where the temp ranges from -20 to 106 (last
week), do we need to use special mortar or do anything special because
of the temp fluctuations?

I think you are in over your head already.