Expert: Daniel Humphrey - 5/9/2010

Question
QUESTION: I want to extent my dining rm wall out 24". This is a gabled side wall of my home, and is located on the second floor of a split ranch home.  I want to know the proper was to properly anchor the new floor beams to the sill plate/header of the first floor.  also can I sister the wall studs to extend the side walls. Do I need to support the new overhangingspace which is to be 24" wide and 12' long with 2 windows???

ANSWER: Gary,

Normally such an extension is supported by a cantilever of the floor framing and again at the roof level. Lacking that, you will need to support it by posts. I know the 24" isn't much, but with windows it could be heavy. Gable walls don't bear much, or any, weight from the roof if you have roof trusses; but the new wall hanging from the roof will weigh too much to expect your lookouts to hold up.

Your objective on the floor is to join as much of the floor sheathing as possible. This may mean cutting the flooring back into the room a bit so you can have some of your new subfloor extend into the original part.

Hope this helps. Write back if you get further along in your planning and have more questions.

Daniel

---------- FOLLOW-UP ----------

QUESTION: Can I use metal posts set in concrete?  Do I need more than 1 in each corner. If I can use metal posts, what is the best way to anchor my bump-out to them?  Is there a free site where I can draw up plans for the town to see when I apply for the permits?  If not a pay site than?  I plan to use a dbl 2"x10"x12 header and 2"x10"x2' for the sides. Can I use 2"x8"x2' for floor and ceiling joist. 2"x6" roof rafters.  Thank you for your help.  I ;love to do these things but hate dealing w/ the town on permits...  Also, I plan to use joist hangers on all floor and ceiling rafters.  I like the idea of removing existing flooring and using new to tie old and new areas together for additional support!  any other ideas or things I need to take into consideration??  Thank you again for your help. where r u located I am in Cary, NC... I might need your help again....

Answer
Dear Gary,

With only 12 feet of wall, two posts can easily carry that span. For best effect, place a timber or I-beam above the posts and set the posts about 10 feet on center, somewhat in from the corners. Realistically, if you are using double 2x10 for your header, you don't need any beam beneath it. The best way to anchor a rim joist to the top of a metal post is to weld a bracket on there that just fits the double 2x10. Joist hangers are fine, and what I would use also.

For going only 24", any 2x will work as a joist, from 4" to 10", depending on appearance and other factors, such as insulation requirements. the 2x8s sound fine.

I don't know of any free site for doing the drawings, but I'll notify you if I come across something.  I have done many pencil drawings for permit purposes and sometimes have found just what I need by doing image searches.

I live in Alaska, where permitting is generally easier.

Daniel