TJI Cantilever balcony

[lubos1984]

Looking at a house with a cantilever of about 33" and inside length about 160". TJIs are 2x12 and are secured to a double header with hangers. The supports on the balcony are W10 steel beams and posts. The inspection was required because the original designed cantilever was 12".
Issues I see is that the roof is not extended completely over the balcony and may cause water infiltration over time. Also code here says something to the effect of 1/6 cantilever for floor joists which seems excessive.
Any thoughts ?

 

[JAE]

1. Not sure how a TJI is a 2x12....two different things.
2. Are the TJI's secured to a double header - or is the header at the end of the cantilevers simply supported by the ends of the TJI's...two different things.
3. Whether the roof extends over the balcony the same distance or not is not relevant. Water/rain would still get onto the balcony either way.
4. There needs to be a proper waterproofing membrane system protecting the wood whether the cantilevers are 12" or 33".
5. For structural strength - the 33" should be checked for their applied loads vs. capacity. Nothing complicated about that.
6. The code may have an empirical limit on span to cantilever ratio....unless it is engineered and checked.




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[lubos1984]

Thanks for responding.

1. Approximate dimensions of TJIs
2. Both ends of the TJIs are fastened with hangers. On the inside it is to a double header, on the outside to the rim joist. Approximately 33" from the outside the TJIs rest on a steel beam.
3. Yes understood
4. Yes
5. Checked, everything is ok there.


I also think it may not be optimal to have the front exterior wall bear down on the TJIs like that. Perhaps have the contractor install additional blocking between the TJIs under the wall to increase the bearing surface.