Wood Guys - This a Problem? 4

azcats · Nov 23, 2020

***I'm wholly unaffiliated with this project***

Driving home over the weekend and saw these condos under construction. Thought the framing was interesting so I stopped for a look.

Any concern with the checks/splits in those cantilevered 4x8s? Or is this already considered in the lumber grading?

KootK · Nov 23, 2020

That's actually a pretty cool detail. I know what you mean about the checking though. It feels as though that would totally compromise your horizontal shear capacity and render the thing two independent pieces of lumber. However:

1) Pretty much every beam and column in every ski lodge in all of Canada has this.

2) Some massive glulam columns at the university of British Columbia have this.

3) When I've looked into it myself in the past, the answer seamed to be that if it was truly partial thickness checking rather than actual shear failure, it was okay. Sadly, I failed to file my hard won research and am unable to produce it here.

4) Part of me feels as though this is just something that woodies choose to turn a blind eye to because their woodies.

oldestguy · Nov 23, 2020

Those are two 4 x 4's stacked. Run the numbers. They might be spiked together, ?? The wood is not pine, probably red wood. Strong stuff.

r13 · Nov 23, 2020

Splitting or just water mark?

LittleInch · Nov 23, 2020

Looks like a future Balcony collapse thread in 8 years time to me. ...

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oldestguy · Nov 23, 2020

And you commenters are engineers??

MIStructE_IRE · Nov 23, 2020

Since the Berkley collapse I hate the idea of timber balconies. You can’t rely on the weathering detail to prevent decay.

What’s up with the ground floor lateral stability here?

JoshPlumSE · Nov 23, 2020

Hmmm, I don't like it. It's not just that the checking exists. But, that it exists at this stage of construction. I've seen checks like that in wood that's been exposed and drying out for 20 years. But, at this age?! If I were the engineer on the job, this would make me want to (at the very least) switch to an engineered wood product for similarly sized beams in the future.

I'm not saying it's inherently dangerous. Things like this can be optical illusions, after all. And, the wood had to be rated in that condition. Presumably, that means it would still satisfy stress requirements.

Lastly, I actually kind of like the long back-span detail for the cantilever. That bodes well for the future safety of the balcony. Someone else mentioned decay. But, we don't know what architectural detail there will be to prevent that. I don't do enough of these types of decks to say that they shouldn't be done out of wood. Especially if they're a one-off family home. For condos and apartments with a balcony like this repeated 100 times, it might be worth it to use some other material. But, tough to justify another material for a single family home.

KootK · Nov 23, 2020

MIStructE said:
What’s up with the ground floor lateral stability here?

That's almost always the way of it with these row house looking things over here. One hopes for an interior shear wall hidden away in there. There was a fun LinkedIn video a while back where somebody tapped the side of one of these with a backhoe and it pancake racked just like you'd be afraid it would. Of course, that changes nothing.

MIStructE_IRE · Nov 23, 2020

I actually saw that LinkedIn video! Yeah, hopefully there’s a shear wall behind there somewhere.

KootK · Nov 23, 2020

I feel like:

1) The guard rails on the sides of the balcony will be sturdier than usual but;

2) Not so much with the guard rails on the front of the balcony unless the rail's meant to span to the sides maybe.

azcats · Nov 23, 2020

Here's a shot of the finished condition.

LittleInch · Nov 24, 2020

Well that covers up all or any evidence of rotting wood alright.

The fact that there are only two beams is what causes me the issue and the fact non one will know they are a bit dodgy until the balcony gets rather "spongy" or just plain collapses one day when a bunch of people lean on the rail admiring the view.

Putting the drain right by the joist could be very bad if the detailing and sealing of the drain isn't perfect.

Remind me never to sit on a a balcony where you can't see the beams or attachments to the building....

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Ron · Nov 24, 2020

That stucco facade has no weep capability at the bottom of the balcony. It will cause the wood to rot behind the stucco...unseen until too late. Makes me suspect the other waterproofing details as well. If this were in Florida, it might be one of my projects in 4 or 5 years! [sad]

IRstuff · Nov 24, 2020

I'm curious:
> what holds the joists onto the beams? are they just toe-nailed in place?
> is the gap between the bottom of the joist and the left side beam supposed to be there?
> is the slope of the deck typical?

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oldestguy · Nov 24, 2020

OK guys. That's two 4 x 4's one above the other. If you go to a typical lumber yard ask for a 4 x 8 and you likely won't find any. However, ask for a 4 x 4 and they have plenty. May explain the situation. Was there a design for a 4 x 8 or two 4 x 4's? Likely a 4 x 8. Or no design?

dauwerda · Nov 24, 2020

@oldestguy, based on the pictures I'm looking at it's definitely not two 4x4's stacked on top of each other.
The following two pictures show splits/checks that are obviously not straight, which would be required for two 4x4's

The end of this beam isn't split at all, indicating it is one piece:

Go to a typical lumber yard and tell them you need lumber to build a condo and they will order it all for you from their suppliers, it won't come from their stock.

JoelTXCive · Nov 24, 2020

I really can't tell if they are two 4x4's or single 4x8's. (I've really zoomed in on all the photos too)

Some of the photos showing the end grains makes me think they are single 4x8's, but then the side elevations make me think that maybe it's two 4x4's with beat up edges.

I think AzCAT needs to go back into to the field and get us better photos. [glasses]

LittleInch · Nov 24, 2020

Joists onto the beams looks like gravity to me...
Gap is supposed to be there as it seems the two beams are at different heights. Interestingly it shows on the RH beam that the cantilever is about 1/3: 2/3 You assume the LH beam des the same thing
Slope looks a little steep but pooling water is a big issue on decks so maybe they go for a 1: 20 or something

The other thing about stucco is to the uninitiated it makes it look like the frame is brick or concrete not timber, ditto the important bits holding the balcony up.

I'm sure one of the balcony collapses recently looked like that.

this one I think

https://www.eng-tips.com/viewthread.cfm?qid=389494

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

dauwerda · Nov 24, 2020

Just curious, is rot much of an issue in Arizona like it is in other climates?

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