Adding a space after a specific character in a string

Basically, (dog)(cat)(mouse) needs to be (dog) (cat) (mouse).

My attempted code:

StringBuilder sb = new StringBuilder("(dog)(cat)(mouse)");

for (int i = 0; i < sb.length(); i ++)
{
   if (sb.charAt(i) == ')')
   {
      sb.insert(i, ' ');
   }
}

String result = sb.toString();

But I'm getting some sort of "Java heap space" error