Replace rotten Rim/Band Board with shorter blocks

[JStructsteel]

Looked a house today and the sill plate and outer rim board is trashed by termites and water damage. Some of the joist ends were damaged too, plan there is to sister a piece of 2x10 to existing joist to have new ends.

All work has to be done from inside, brick on outside of home.

For the rim/band board, I was going to suggest they put a 2x6 sill plate down, and then bear the new joist ends on that out to the edge. In between the joists, put in blocking flush with the ends to re-create a band board.

Whats your thoughts on that detail? there is no way to waterproof i?

Any good details for sistering a joist end? Nail pattern or thru-bolts? I wanted to sister on both sides of damaged joists, wondering if thats overkill?

Thanks

 

[NorthCivil]

Not sure what you are getting at. best to post a sketch to convey your thoughts.

Is this problem area bearing on the foundation wall, or bearing on another stud wall below?

Cutting the rotten bits off the end of a joist and sistering it to extend it to the supports is what I define as a "bandaid" solution. Bandaids aren't meant to be permanent. I have actually come across this detail before, when called in to inspect rotten framing. It was this solution, that had become rotten. Someone had fixed the rot like this, and it had rotted out again. Talk about dangerous!

I dont like the idea of chopping up the rim joist. That is a major part of your diaghram - you can't just cut it into bits.

I've been down roads like this many times before. If you don't have expertise in building science to stop the moisture issues, I recommend you find an engineer who does to support the repair. No sense repairing the structure if it will just rot out again.

Regarding the brick facade - if it is in the way of doing things right, it has to move. It sounds like that is the case.

 

[dik]

Can you use a penetrating epoxy... often used for boat re-construction?

Dik

 

[JStructsteel]

Right now there basically is no rim board, its been eaten by termites and rotted away from water damage. I have attached a detail of my repair and what I am thinking of doing.

the contractor is handling the waterproofing issue. Soffit repairs, gutter repairs, weep holes.

He is not going to remove the brick.

I was brought in to address the structure.

@ Dik, there is just too much rot. Were talking 50% of the house.

 

[dik]

and the floor joists are not affected?

Dik

 

[XR250]

jrisebo;

That is how I normally take care of them.
Make sure you check the floor sheathing and even the wall bottom plate as they usually take a beating as well.

 

[dik]

With brown rot (aka dry-rot) you can have lost 30% to 40% of the strength without a measurable weight loss. In case you're curious.

Dik

 

[JStructsteel]

Some of the floor joists are effected, thus a repair or replacement.

 

[KootK]

In between the joists, put in blocking flush with the ends to re-create a band board.

I've got no problem with the piecemeal rim board. I see the diaphragm chord/strut here really being the top of the block wall and the rim board as just vertical shear transfer. You may struggle to get quality connections from the blocking into the connecting stuff but the show must go on.

Any good details for sistering a joist end? Nail pattern or thru-bolts? I wanted to sister on both sides of damaged joists, wondering if thats overkill?

I don't like bolts. Too much slip before engagement. My first choice would be screws followed by nails. In my experience, the only way to make a go of it is by dealing with the moment as a couple resisted by two, spread apart, fastener groups. Tough, and tedious to design, as moment transfer through a single fastener group.



I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[KootK]

I like your graph paper with the numbered lines. Where do you get that?

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[JStructsteel]

KootK, I print the graph out from AutoCAD as needed, can do regular paper, or heavy stock for in the field.