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