In the process of framing a salt box addition and have two questions on the framing of it. The addition is about 22 X 12 and two stories.
Do I need to balloon frame the wall with the kneewall? It would seem that I should since otherwise I would think the kneewall if framed platform would want to hinge at the plate. Second, for the second floor floor joists do I need to run them perpendicular to the roof ridge, or can then be parallel.
Made a mistake, three questions. For the second floor the ceiling will be partially sloped. Will the rafter ties running from the top plate of the front wall (kneewall in back) to the mid span of the rear rafters be sufficient?
Thank you.
Replies
hi, here's my 2 cents worth...
1) yes, balloon frame that wall. stronger, and easier to insulate well.
2) i would think perpendicular would be easier, and cheaper. (do you really want 22 feet long joists?)
3) should be sufficient. i'd finish by strapping the ties with 1 x 3 pine to level.
good luck!
This is my gut reaction, though I would consult an engineer. (You may be required to get some engineering to obtain a permit.)
1. Either balloon frame or brace the knee wall with braces running back at a 45 degree angle from the plates to the floor (if you have some crawl space under there)
2. Not necessarily, though it would be best. If you run your joists perpendicular to the wall it will be the floor sheathing that provides the tie-in to the walls. This means you might need some engineering to make sure the end joists are tied into the walls well enough to resist the force. The floor sheathing glue and nailing schedule are critical in this senario as well. But shouldn't present any major cost or difficulty.
3. As for the collar ties, it depends on rafter length and size. The rafters would need to be be sized to carry the full span and half the ceiling load.