So my floor joists in my 1917 house are 2x6, the first 10 floor joists are rotted at the end similar to what is shown in this picture. They have been sistered, but the sister does not extend the full length to the triple 2x6 beam in the center. At the triple 2x6 beam, the joists butt against eachother, they do not overlap.
The structure is supported as seen by stacks of things, in this case some 2x6 wood pieces which sit on top of some cement blocks, no proper footings. I'm implementing plans from an engineer to replace this with 6x6 support posts holding up triple 2x10 beams near the exterior end of the joists, these will be on specified footings.
The engineer's plans specified using the existing triple 2x6 beam in the center, but it's on stacks of cement blocks and is sagging between 2 colummns where the boards are spliced away from supports - all 3 boards splice between 2 columns, and this is where the floor sags, and it's part of where the stairway is supported. I plan to replace this center beam with triple 2x10 with joints properly supported.
Here's my question: the span between beams will be 11'. I want to either sister 2x8's onto the damaged joists OR replace them. I'd rather replace them, but I don't think I want to go as far as replacing all floor joists since there are floor joists that are not rotted. The floor joists have clearly been replaced because they are not true 2" x 6" boards like what would have been in use at the time of original construction and which I've seen in use elsewhere in the house.
If I replace, it makes it easier to put in joist hangers where I notch the joists for the beams, which need to be placed for supporting the 2x6's which aren't being replaced.
If I sister, it makes it easier because I don't have to remove old boards and devise temporary support while this work is in progress... But I don't know how I get a joist hanger in, or is there another way? Or do I fur in 2x2 under the 2x6's and use a triple 2x joist hanger?
Which way should I go?
The structure is supported as seen by stacks of things, in this case some 2x6 wood pieces which sit on top of some cement blocks, no proper footings. I'm implementing plans from an engineer to replace this with 6x6 support posts holding up triple 2x10 beams near the exterior end of the joists, these will be on specified footings.
The engineer's plans specified using the existing triple 2x6 beam in the center, but it's on stacks of cement blocks and is sagging between 2 colummns where the boards are spliced away from supports - all 3 boards splice between 2 columns, and this is where the floor sags, and it's part of where the stairway is supported. I plan to replace this center beam with triple 2x10 with joints properly supported.
Here's my question: the span between beams will be 11'. I want to either sister 2x8's onto the damaged joists OR replace them. I'd rather replace them, but I don't think I want to go as far as replacing all floor joists since there are floor joists that are not rotted. The floor joists have clearly been replaced because they are not true 2" x 6" boards like what would have been in use at the time of original construction and which I've seen in use elsewhere in the house.
If I replace, it makes it easier to put in joist hangers where I notch the joists for the beams, which need to be placed for supporting the 2x6's which aren't being replaced.
If I sister, it makes it easier because I don't have to remove old boards and devise temporary support while this work is in progress... But I don't know how I get a joist hanger in, or is there another way? Or do I fur in 2x2 under the 2x6's and use a triple 2x joist hanger?
Which way should I go?