char column with a single space as the default not working

All;


I created a table like this:

create table z (charcol char(1) default  ' ', intcol int);


Then I inserted a row with a single space in the charcol column and 
another insert letting the table use the default value:

insert into z values (' ', 1);

insert into z (intcol) values (2);


However neither of the inserted rows actually retained the single space 
in the charcol column:


select '[' || charcol || ']', intcol from z;
  ?column? | intcol
----------+--------
  []       |      1
  []       |      2
(2 rows)


Thoughts? Is it possible to add a single space to a char column without 
it getting truncated?


Thanks in advance