More wood decks collapse, this time in New Jersey 1

[hokie66]

https://www.foxnews.com/us/new-jersey-deck-collapse-wildwood-firemans-convention

 

[Pud]

I don't think I would be crowding onto the decking next door to get a better view!


Politicians like to panic, they need activity. It is their substitute for achievement.

 

[IRstuff]

It looked pretty reasonable, before. Interestingly, the roof overhang stayed intact.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[LittleInch]

This picture shows the deck survived as a complete slab.

Looking closely it looks like the main beams run parallel to the building with only the odd bit of 10x2 actually holding it up!!

Looks like quite a heavy deck to start with.

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

 

[IRstuff]

That picture doesn't show the details, but a picture of the other side does

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[Sym P. le]

Re: Image posted by LittleInch - The joists and ledger do not look healthy, nevermind the logic in the structural layout. The deck slats also allow for generous water penetration of the hidden structure. Obvious external decay does not bode well for that which could not be seen.

Re: Image posted by IRstuff - An initial glance can be dismissive of the misaligned columns given stitching of multiple images by Google Earth, however closer inspection reveals either significant maintenance issues, poor construction techniques, or both.

EDIT: It seems I missed a seam across the middle of the highlight, but I will otherwise leave the post as is. From multiple angles, something is not right with that deck.

 

[Sym P. le]

I think we have seen enough harm caused by external decks. It is time for appropriate authorities to step up with campaigns to advise home owners of issues stemming from external decks. In current practice they are hazards. Although they are pleasant retreats for a few folks at a time, they are injury/death traps for congregations of people. Insurance policies do not undo damage to the lives of friends or family members.

 

[IRstuff]

I saw the wiggles in the photo I posted, but Google Maps photos aren't always straightforward

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[Earth314159]

I find that contractors don't take decks seriously. If they don't follow your details, they say "why are you so concerned with just a deck". It is usually the connection into the building that is the issue. Decks can be design to be as safe as any other portion of the building. It is just that they aren't designed or built well.

This appears to be a drip through deck (there is no membrane and water can drip through the deck) with a soffit. This is not great since the rain water goes through the deck but the soffit help retain the water. One thing this deck had going for it was the roof over which would have minimized the exposure to rain. Good practice is to avoid drip through decks that are supporting a portion of the building such as this case. Although the roof protects the deck, it is not a great idea to rely on the drip through deck to support the roof. I am also not a fan of multilevel drip through decks.

From the photos on google, it looks like the joist were running parallel to the facade which is unusual. I couldn't see any connections for the beams into the building. There should be beams at the column locations.

One report said that this was a pancake type failure. Another witness said the first level came down first and the other level came down slowly. This contradicts the claim that this was a pancake failure.

There doesn't appear to be much damage to the facade of the building. Glass and siding are not broken or ripped away from the face. However, the connection to the building does not appear to be substantial. The other possibility is that the one witness was correct. The fist suspended level failed first, the columns were pushed outward and then the upper level was pulled out.

 

[1503-44]

Looks like nothing more than a 2x10 nailer onto the lower wall header or floor joist.

A relatively new construction, no?

 

[Earth314159]

A 2x10 ledger is a common detail. The direction of the joist are usually perpendicular to the ledger. Otherwise, the ledger has to support point loads from the beams.

The age of the building is very important to know. The roof is suppose to be supported by the deck columns (even through the roof did not collapse) which implies the decks were original components.

 

[Tomfh]

Looks like nothing more than a 2x10 nailer onto the lower wall header or floor joist.

It's a very common method, and a common point of failure if it's poorly connected to the building, which they often are.

My mother had her deck replaced and it had similar shortcomings. A few nails here and there and that was it. I ended up installing bolts for her.

 

[RAB678]

Diamonds and rust

 

[LittleInch]

Column connection looks poor also

Reports say the bottom deck moved first so whatever the columns were testing on maybe sank?

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

 

[sandman21]

I like the people standing on the deck looking at the collapsed deck.

 

[msquared48]

Nothing like getting decked in Jersey.


Mike McCann, PE, SE (WA, HI)

 

[jari001]

Man, and I was just about to start bothering my parents in NJ to have their deck rebuilt!