Hand Tools Archive
I am building a room onto my summer place that will be framed first as a deck and then walls will be erected above the deck structure, and then a roof will be put on. Size is 8 x 14 feet. The deck is supported by a ledger at the wall, and the other side will be supported by a beam running about 7 feet out from the wall, there will be a cantilever of 1 foot, footings are in, and these factors are fixed.
The "room" will function as a screen porch but is being built to have full wall strength, and the capability to completely enclose the structure and later insulate it or whatever. The real intent though is that the porch needs to be secured many months of the year, and screens need to be as full as possible, yet the structure easily boarded in for security, so while I want a screen I also want secure walls. Probably the easiest way to get there would be to stick frame the structure, and sheet the lower walls while leaving plentiful and large window openings under conventional headers.
So here is the question. Notwithstanding the stick option I would like to frame the long wall pole style with 3 x 6"x6" posts on 7 foot centers, with a large header over the top. The only problem with this approach is that the posts would be resting on the deck edge with no particular structure under then. This is because the deck is joisted on 16 inch centers extending over the 7 foot support beam one foot. It should be easy to ensure that the post all sit above a joist, but the load transfer of a beam to 3/4 ply deck/to rim joist/and joist seems inadequate. My solution is to either pair two of the 2x10 joists at the corners and center point, so that the transfer is at least to that extent. Another option is to place a 2x12 girder notched into the base of the posts, along the base of the wall, this would transfer the load Across the whole surface just as the average pole structure use beefy poles and beams to carry roof or second story loads.
I have seen structures where the front rim joist was built up, but I don't really think that will make maters better in this case where the front rim joist is not directly supported by posts.
This Bob Villa piece shows the basic structural layout, though he is attempting a very different structure overall. Start at 1:40. He also has walls on two sides and the posts are set back enough to be almost over the beam.