[hebrewdiver]

I'm extending my bedroom and adding a 4' balcony on the outside of bedroom. I'm using 2x10x16 for the floor joist. The length of the extention is 12'6" leaving 3'6" for the balcony. I want to know if I can cantilever the the untreated wood for the balcony.

 

[Ron6519]

If the framing will be fully enclosed, so you can use regular framing lumber. What are the plans for the top surface to waterproof the structure.
This cantilever has been engineered?
Ron

 

[hebrewdiver]

the bedroom extention will be fully enclosed but the balcony which is the cantilever section will not there fore the 2x10 that are making up the balcony area (4' long by 24' wide) will not. The top portion or flooring of the balcony can be pressure treat lumber(haven't installed it yet. If I enclose the untreated in some pressure treated plywood it will be ok. Or should I just bite the bullet and purchase pressure treated lumber for the floor joist that will be cantilevered?

 

[Scuba_Dave]

I'd go with PT, not that much more
Then you don't have to worry about a sealed deck & water run off

 

[Gary in WA]

Different length cants for different locations. Some are 24" max. with 2x10, some are 36"max. Longer if engineered as Ron said.

Check with your local Building Department.

Page 3 and 4: http://www.bssconline.org/Homebuilders_Guide/Chapter4.pdf

Page 2, number 6: http://www.ci.apple-valley.mn.us/In...tions/Informational_Handouts/deck_handout.pdf

Everywhere is different. Be safe, G

 

[rwa]

I have to ask, is this a true cantilever (no support on the outer edge)? I'd also caution extending the floor joists the entire distance. Even PT lumber will need to be replaced at some point in time. I doubt that you would want to pull an entire floor just to replace a joist that is rotted at the exterior. Consider sistering off the floor joist whatever distance is necessary. Then, when the exterior does need to be replaced, in the worse scenerio, you could replace it by pulling the a portion of the ceiling below.

 

[Ron6519]

the bedroom extention will be fully enclosed but the balcony which is the cantilever section will not there fore the 2x10 that are making up the balcony area (4' long by 24' wide) will not. The top portion or flooring of the balcony can be pressure treat lumber(haven't installed it yet. If I enclose the untreated in some pressure treated plywood it will be ok. Or should I just bite the bullet and purchase pressure treated lumber for the floor joist that will be cantilevered?

I still don't know how you're constructing this. Is there some sort of flooring? What is it made of? Is this going to be some sort of mini deck with wood on top or a waterproof material?
You wouldn't use a plywood to wrap regular framing material.
Ron