Glulam Modification/Replacement 3

[Bhotar3]

I’ve been tasked to Analyze and give a Engineering Judgement on a damaged glulam beam for an apartment complex. I wanted to get a feel for potential solutions from the board here, as I don’t have a ton of experience dealing with Timber design.

A truck didn’t clear the bottom of the beam, and At first glimpse, there is pretty significant damage to the structure. It looks like it gouged out a pretty decent chuck of the member. Also, it looks like there has been some significant moisture damage now that the beam is exposed.

Are there any potential retrofit ideas here? Could they potentially bolt metal plates on both sides of the affected portion? I would assume you can not cut out and splice in a new beam just at the damaged location (or maybe you can and just need to design significant splice connections).

Or is a complete replace in kind the only realistic option? It would require substantial bracing, as this complex is 3 stories.

 

[NorthCivil]

Bhotar3 - are you a structural engineer, or a building science/envelope engineer?

This little rotten gluelam looks to be a small piece of the puzzle with this building. if your expertise is only in structural, I would be looking to pass the buck to someone qualified. hopefully having written nothing with your name on it, to be found in five years in a huge pile of documents while somebody is looking for somebody else to sue.

 

[dik]

Mike's got it... immediate shoring and your report should note that the same condition could occur elsewhere.

Dik

 

[dik]

If this job required, 2.5 hours of travel and inspection, and 2 pages of Engineering report. What would you guys charge the client? (Just recommendation. Not further consultation)

Depending on what the market can bear... but, a two page report + 3 hours... would be about $3000 min.

Dik

 

[dik]

I've attached an Appendix from one of my reports... it's been included in a dozen or more reports... just toss it into an appendix...

Feel free to use whatever parts you choose... or, just for your own information... no attribution required. The article explains why it's called brown rot and because of the appearance of the deterioration it is often referred to as dry-rot.

Dik

 

[Bhotar3]

@NorthCivil
Civil/Structural. For this initial phase of identifying if the beam needs to be replaced, I would like to think I am qualified.

If the 2nd phase - of developing potential solutions and design - ends up being something I am uncomfortable with, I don’t mind passing this off.

The architect simply needs something in writing explaining the existing condition and whether it can be repaired or needs replacing.

@Dik. Thank you! Big help.

 

[dik]

No reason to pass it off... great learning experience. You can use an incremental borer to take 'core' samples for a university to check for fungi, etc. Go out to a local university and talk to a couple of mycologists and learn about the little critters... it's fascinating.

Dik

 

[dik]

I have papers I've prepared for Brown Rot, Historic Brickwork, etc. that I include with reports as 'added information. Information is continually added... in that one, I've removes some of the biologic info on the common types of fungi, but, have it if necessary.

Dik

 

[Bhotar3]

Dik, this is great info.
If you have any useful links/resources where I could learn more about all of this, I would love to do my research! Thanks again.

 

[dik]

Just info picked up over the decades... we homeschooled our youngest son to an equivalent Grade 13, Honours English... I was responsible for his science and mathematics studies that fit into my wife's framework for study... he was schooled using a thematic approach. Worked great. Picked up a little biology in the process.

You can modify it, shorten it, or whatever and incorporate it as a Appendix item for your next half dozen Brown Rot reports... I've provided technical information on this in 4 or 5 provinces. I withdrew from one project in Saskatchewan because the PM wouldn't approve about 40 hours of work. My thesis was that a building 180' wide and 1200' long should be reconstructed due to brown rot deterioration, and, I was researching actual technical info to back up my claim. He couldn't understand why I could, outright quit the project.

Dik

 

[Bhotar3]

I wanted to give a general update:

I conducted the inspection. Sheathing, stucco and other components were not installed properly around the beam per manufacturers specifications, in addition to consistent leaking of some sort (source not identified at this point).

I recommended immediate temporary shoring as precaution and for public safety.
I composed an email and a portion stated “Contact a licensed Contractor to provide adequate shoring, under the supervision of a Structural Engineer.”
I will echo this sentiment in my report.

My question to you guys is, does the shoring plan fall under my Responsibility now that I’ve recommended it as a result of inspection?
I feel as if shoring should be construction “means and methods”, in that it will be up to the contractor to come up with the best way to shore it while still allowing traffic through the Drive-Thru.

Am I responsible in creating a full-blown, sealed, shoring plan, or will supplying the appropriate loads to the contractor suffice?

Thank you for your continued input!

 

[dik]

Unless your scope of work includes it, and it likely doesn't. This would normally be undertaken by a contractor and he can provide the engineering drawings.

Due to the urgency, you can offer your services, for an additional fee to do this. Impress upon him that the work has to be undertaken immediately.

Dik

 

[dik]

The architect simply needs something in writing explaining the existing condition and whether it can be repaired or needs replacing.

There's nothing that can be repaired... it needs total replacement. There may be other areas that are just as dangerous.

Dik

 

[wikidcool]

I don't know if this is the case for most structural engineers who don't specialize in it, but my professional liability insurance does not cover shoring design. This was not highlighted to me anywhere along the way during obtaining it. It's probably buried in 30 pages of fine print somewhere. Thankfully, it came up by chance in a conversation with my insurance agent.

If you're not positive you're covered for designing shoring, I highly advise that you check. While it's common for a contractor to ask me, I refuse to provide even the tiniest amount of advice or guidance on shoring or means and methods. And the exclusion is also noted in my contract. When I explain I'm not trying to be difficult but I'm just not covered for that, they understand.

 

[RickyTickyTavi]

Generally, when i'm doing repair design I give the shoring loads to the contractor and put language in my repair drawings that the building or structure needs to be shored so as to not incur any additional damage.I also will have a note stating that shoring needs to be signed and sealed by a professional engineer and I require a submittal for me to review. If is a condition where say the lateral system is compromised and residents/tenants are still there, I'll give additional guidance. If my repair design requires a phasing approach, I'll also tell the contractor how to do it in phases.

Also, just a heads up, the comment "sheathing, stucco and other components were not installed properly around the beam per manufacturers specifications" is raising flags for me. The owner may sue the original contractor/architect/engineer for damages, so be sure to keep really good records of everything you have done on this project. You could get subpoenaed.

Welcome to the world of Forensics Structural Engineering.

 

[dik]

If you don't mind telling us... what happened?

Dik