How To Build Cantilever In Open Web Type Floor Framing Structure With Construction Standard Lumber

[@nb-eq6rw]

I have a 1ft cantilever for a window box. It is raised above the floor 18 inches. How does that work? just a 2x6 cripple wall?

[@gregvancom]

I would have the engineer or building designer provide instructions. Here is a video that might help kzbin.info/www/bejne/roGll3Z9Zb2cbKs

[@Oldhogleg]

That reminds the biggest issue with cantilevered framing projecting beyond the exterior wall is less about the framing itself, but flawed methods of sealing/flashing the wall penetrations, not to mention the fenestration above. Of course one way is to make the deck an impermeable one, but States like California have amended their building code to require impermeable decks to be engineered with something like a 300% safety margin due to recent deadly catastrophic failures from water infiltration and rot concealed from inspection by the impermeable deck encapsulating encloser. But the most common issue of faulty seal/flashing is water infiltration where the joists protrudes through the exterior wall material in an open frame deck. Easy enough to flash the top of cantilevered joints with a Z-bar flashing set in a saw kurf on top of the joints. But not so simple to reliably seal/flash the sides of the joints. The only reliable way to seal/flash the sides of the joints is to not let the rain reach them in the first place by having the bottom of the Z-bar flashing under the deck boards wide enough to screens the joist wall penetrations from the rain, probably something like 6 to 8 inches out from the wall.

[@gregvancom]

Yes, there's a lot more to a cantilever than just the framing.

[@VP411Designs]

Great video, very helpful. Of topic, For existing home with load bearing wall, Can you join two small beams using metal connector between the two together to make one long beam to get rid of a column holding up the weight?

[@gregvancom]

Probably not.

[@evak.5234]

Question on how to insulate kitchen that is bumped out and piper are under cantilever. Hard winters, pipes freeze. Suggestions from someone skilled on insulating cantilever properly?

[@gregvancom]

Check with your local contractors or building department. The answer to your question has to variables for me help with.

[@sakana1977]

Is is possible to cantilever off the side of floor joist? So the cantilever is perpendicular to to the existing joist.? The joists are made of solid timber.

[@gregvancom]

I don't think you would be able to get the on center joist spacing you might need. For example, the joist might be spaced 40 inches on center. I'm not suggesting it wouldn't work, but I couldn't get it to work in this project.

[@KevinBaxter]

Excellent video. Thank you....this is exactly what I was looking for.

[@gregvancom]

Great to hear!

[@fredericrike5974]

Just curious- why can't trusses of more length be used to gain the structure outside the wall framing? In other words, instead of all the sistered 2x large (spelled even more expensive than trusses) be run across the outer wall framing continuously ? It strikes me it would use less material and labor. But my background is as a plumber, so I'm going to do the "smart" thing and ask the dumm question! FR PS; This looks extremely attractive to me for the second example you show- once you reinforce the long truss to act as a support for the interior end of your floor joists, running longer trusses for the porch floor would significantly decrease costs and would also leave the trusses clear to run AC ducting, etc if not blocked by all the solid 2x's shown scabbed on. My thinking anyway! fr

[@gregvancom]

Most open web joist are built so that the ends of the joist sit on load bearing walls or beams, but can be built with cantilevers most of the time.

[@fredericrike5974]

@@gregvancom Could the design/build for those joists be changed to do so? I do get your point- to do this at all a verticle support member would have to land right on the load bearing wall. I just find the large 2x scab on (or sistering) potentially only shifts the joist's point of load mostly to the far end and leaves it trying to lift the joist- where direct pulling forces will more likely cause nails to fail, as well as being costly and cumbersome. Thank you for your reply- my "personal exp" is as a plumber and framing as it applies to, hopefully, my new two story garage- I only foresee a big enough "porch" to access the 2nd floor entry door- three feet wide by say four across. FR

[@monahandesign]

As a current roof/floor truss designer in Florida. Top chord pitch breaks in 4x2 floor trusses are not an option. However they are very possible with flat trusses. They are floor trusses that are 2x4 like roof trusses and you can have multiple plies and apply a slope for a cantilever depending on loading. We often use flat trusses in floor situations to carry floor truss girder type loads.

[@FlashGamer521]

Would it be weird to use steel beams to support a cantilever in an otherwise wooden structure?

[@gregvancom]

No, go for it, I've seen it done plenty of times.