Hardi has about 30% cellulose fiber in it and the rest is cement. Hardi shrinks after it is installed so you must keep it tight to the the next board and not leave expansion gaps on either side. It de ... read more
They are definitely measured differently. The insert window you would measure inside the existint window frame, which in most cases is built out of 3/4" lumber all the way around. For a full replace ... read more