Sounds good to me. Treated 1x4 should last at least several years even
in direct contact with the ground. If you are really able to do it
within 8 weeks you probably don't even need treated lumber (of course
I'm sure we've all started projects that take longer than we expect so
the treated might be good insurance). The only possible complication I
can think of would be if you got lots of rain and your screed boards
warped. I suppose you could go to the trouble of sealing them up (maybe
with some Thompson's Waterseal) if that really worried you.

Good Luck

JD wrote:
I am going to build a large brick patio ( 350 sq ft). Since I will only be
able to work on it during weekends. I was planning on doing it in sections.
My thoughts are to excavate the entire area, then pack my base and then put
up screed boards for the sand & leveling. I was going to do it in sections
and leave the screed boards buried in the sand and not remove them. If I
use treated 1x4 it will take quite a while for them to rot. Does anyone see
a problem with doing this? Is there another way to do this in sections over
6-8 weekends?
Thanks
JD