Expert: Dave Johnson - 7/22/2008

Question
WE ARE BUILDING A GARAGE APT FOR MY SON. IT HAS TWO GARAGE ENTRANCES. THIS IS A NINE FOOT WALL 2X6 ON 24" CENTERS. ONE WALL IS 21 FEET LONG. HE WOULD LIKE TO PUT IN A 18 FOOT GARAGE DOOR. IS THIS POSSIBLE AND WHAT TYPE OF HEADER IS BEST FOR THIS SIZE OPENING. THE SECOND WALL HE WANTS A 8 FT DOOR WHAT IS THE BEST HEADERS FOR IT. THANKS FOR ANY INFO YOU CAN GIVE
                         THANKS  JEFF

Answer
Hi Jeff,
For the 18' door: if it is in a gable wall, there is little downpressure and anything that will not sag on its own will be fine. If it is in a sidewall, you need to build a triple 2"x12" laminated with plywood.(or go to your lumber yard and ask them for a "glue-lam" or "micro-lam" and they'll tell you the size.
The 8' door is okay with triple 2"x6".