My stove has been in for a year now. Loved it all last winter. Durant double wall chimney from the wall up. Durant single wall from the wall to the stove (90 from wall, 3ft down then 90into stove back) my problem is the single wall pipe, I used the recommended three self tappers and each joint and had it apart 4 times last year for cleaning. Now all the holes are stripped and sloppy and I need to change the pipe. Is this common? Always used a nut driver not a drill. Would better thicker pipe hold up better?