chmod immediately?

I want to chmod a file right after finishing writing to it.

  :0c
  <snip>
  echo "<h1>END of WEB</h1>" >> $WEB/$FILE.html;
  :0a
  | chmod a+r $WEB/$FILE.html

This recipe works only about 50% of the time:-<
It fails with message WARNING: can't access.....
I tried
  | sleep 5;  chmod a+r $WEB/$FILE.html
but, did not improve.

Is there better way?
TIA
_/_/_/      Mitsuru FURUKAWA      _/_/_/
_/_/_/        Tokyo, Japan        _/_/_/
_/_/_/     mailto:furu(_at_)009(_dot_)com    _/_/_/
_/_/_/  http://www.009.com/furu/  _/_/_/