Do You See Any Construction Problems With This Roof Framing? 6

jfklein · Dec 8, 2022

I am on the board of directors for small condominium in Canada. The building was built in 1979, it is wood-frame construction and has a flat (i.e. low-slope) roof.

Recently we had a roof consultant inspect the roof in preparation for replacement of the weatherproofing membrane, that covers the roof, next year. When looking at the framing below the plywood deck of the roof the consultant noticed what he described as questionable construction work and recommended that we hire a structural engineer to check it out and determine it's structural integrity.

The consultant made his observations of the roof framing from a hatch opening that penetrates through the roof structure making it possible to see below the deck. I have attached four photographs taken on opposite sides of the hatch opening, looking down the cavities between cross-strapping members that support the deck. On the photos I have indicated the consultant’s comments about the construction work.

My questions for this forum:

What do you think about the quality of the construction work shown in the photos, specifically the attachments between the components of the roof - the plywood deck, the tapered 2x4 cross-strapping members and the 2x10 joists?

Does it look like typical construction work for a wood-framed building?

Do you think the consultant’s comments about the structural integrity of the roof are justified?

phamENG · Dec 8, 2022

I'd say there's not enough information here to make a call. Go with the inspector's recommendation and hire a local engineer to check it out.

RPGs · Dec 8, 2022

pham is on the level: hire a local engineer for an evaluation and report, with sign/seal. There are too many considerations to make and--though a picture is worth a thousand words--a site visit is priceless.

jfklein · Dec 10, 2022

phamENG said:
I'd say there's not enough information here to make a call. Go with the inspector's recommendation and hire a local engineer to check it out.

RPGreen said:
pham is on the level: hire a local engineer for an evaluation and report, with sign/seal. There are too many considerations to make and--though a picture is worth a thousand words--a site visit is priceless.

I understand your point that an engineer should be hired to check it out. But do you see any significant problems based on what you can see in the photos?

Here are a few more photos of a joist hanger and close-ups of the joists pulled away from their hangers:

phamENG · Dec 10, 2022

Yes, I do see issues in the new photos. Your engineer should be able to document them for you.

Be prepared to remove finishes. Despite popular opinion, we are not issued xray goggles when we become engineers.

jfklein · Dec 10, 2022

phamENG said:
Yes, I do see issues in the new photos.

What are the issues that you see in the new photos?

SWComposites · Dec 10, 2022

It looks like moderately crappy construction. Though I have owned houses with far worse conditions.

Your consultant recommended hiring a structural engineer. Other knowledgeable people here made the same recommendation. That is what you should do. Regardless of the cost. No one here is going to give you a detailed answer one way or another.

dvd · Dec 10, 2022

I ask myself if the nails through plywood deck are insulation board nails. Is this the original roof replacement from 1979?

jfklein · Dec 10, 2022

dvd said:
I ask myself if the nails through plywood deck are insulation board nails. Is this the original roof replacement from 1979?

They wouldn't be insulation board nails because there is no insulation board above the plywood deck. The only thing above the deck is the membrane, which is a BUR (Built Up Roofing) system membrane. Thermal insulation is only the fibreglass batt between the joists as shown in the photos.

Apparently the roof was already replaced once since 1979, according to information from our consultant.

jfklein · Dec 10, 2022

SWComposites said:
Your consultant recommended hiring a structural engineer. Other knowledgeable people here made the same recommendation. That is what you should do. Regardless of the cost. No one here is going to give you a detailed answer one way or another.

I'm only trying to gather as many opinions as I can. The ones I have so far have not been universally the same. In fact I have received one opinion from an engineer, based on the photos and the age of the building, that an inspection isn't even needed.

One of the concerns I have is that an engineer could be biased to recommend an extensive investigation and/or extensive repairs because it would be paid work for themselves or their company. The cost, in particular the repairs, could double the cost of the roof membrane replacement and may not be affordable for some of the owners in the building.

IRstuff · Dec 10, 2022

It's not clear that the joists are "pulled away" from the joist hangers, since the hangers are all bent, suggesting that the joists are still connected to the bottoms of the hangars. Presumably, there should have been nails on the U-part of the hanger, so when the joist pulled away, the bottoms went with them, resulting in the hangers bending.

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kipfoot · Dec 11, 2022

jfklein said:
One of the concerns I have is that an engineer could be biased to recommend an extensive investigation

It's a bit off-putting when you ask a question on an engineering forum and then imply that engineers are dishonest. You have to be able to trust the consultant that you hire, and don't hire someone you don't trust.

I'd say there are two things to figure out:
1) the separation between a joist and its support may indicate some overall movement in the structure. An engineer needs to visit the building to see if there is any other evidence to support this or perhaps conclude that it's related to wood shrinkage or something else.

2) There's some doubt about how the sheathing is fastened to the furring* and how these pieces are fastened to the underlying framing. If you see a nail poking through, it doesn't mean that a nail wasn't also placed correctly. If you don't see a toe-nail, there could be one on the other side, which may be sufficient. In my opinion, this evaluation and work would be done from the top, so you won't know really the extent of the work that's necessary until you strip the roofing and examine it.

*furring is an imprecise word for these pieces, but someone can remind me of a better term.

Enable · Dec 11, 2022

As someone who used to work with condominium boards on a daily basis, I would strongly caution you against using the opinions of an online internet forum to sidestep the recommendations in a formal report; especially since those recommendations pertain to life safety, and the Board of Directors (BOD) commissioned the consultant to perform the work. YOU, the OP, and the rest of the BOD have a fiduciary duty to your members and are legally obligated to behave in a prudent, responsible manner.

If something should happen, and it came to light that you made the deliberate decision to not act on the recommendations of an official report, you personally will be held responsible. You will not be protected by the corporate structure. Additionally, it is a near certainty that the condominium insurance carrier would claim you were grossly negligent and rightfully deny you coverage, which means all legal expenses and restitution are on your dime. I've seen it happen on more than one occasion, and the outcome was devastating for the board members.

While the building has stood for some time, and it is probably unlikely anything too bad will happen in the foreseeable future, is that a risk you personally want to take? You are talking about the cost of an investigation, which might amount to a few thousand plus minor repairs. Do what the report recommends and sleep well; it's not worth it for a couple hundred out of your pocket.

JStructsteel · Dec 11, 2022

Its 42 plus years old. Are there major signs of impeding failure, or extensive damages to finishes?
Are you or the homeowners prepared for the ramifications of a engineers report?. Would this report spill over to other Condos in same development if the local building official caught wind of it?

Start with the engineer report if concerned still.

gte447f · Dec 12, 2022

Kootk, "furring" strips got your point across just fine. In this case/application, I sometimes call them "sleepers".

To the OP, your inspector has raised some potentially valid concerns that require further investigation to be prudent. For starters, much better visual access to a representative sampling of the existing conditions would need to be provided (i.e. selective demolition and/or removal of finishes).

jfklein · Dec 12, 2022

IRstuff said:
It's not clear that the joists are "pulled away" from the joist hangers, since the hangers are all bent, suggesting that the joists are still connected to the bottoms of the hangars. Presumably, there should have been nails on the U-part of the hanger, so when the joist pulled away, the bottoms went with them, resulting in the hangers bending.

I checked both sides of the U-part of one hanger on a joist that is on the south side of the roof hatch opening (shown in one of the photos above). It does not have any nails on either side into the supported joist. So, unless there is a nail on the bottom of the U-part, it appears that the supported joist is not attached to the hanger.

I’ve put all the photos I took into a Google Drive folder here:
https://drive.google.com/drive/folders/1nGb2y7S5WwoOcDwLk4oeRlYzO11RhniA?usp=share_link

gte447f · Dec 12, 2022

I like a note on drawings that says to fill all holes in joist hangers with specified fasteners, unless noted otherwise. To me, open holes in joist hangers is always a red flag. That being said, Simpson lists multiple capacities for some of their hangers depending on how many nails are used to install. In that case, you should be able to at least expect to to see symmetry of the nails and open holes in every joist hanger. Haphazard nails and open holes from one joist hanger to the next is again a huge red flag of possible shoddy construction and workmanship.

jfklein · Dec 12, 2022

kipfoot said:
It's a bit off-putting when you ask a question on an engineering forum and then imply that engineers are dishonest. You have to be able to trust the consultant that you hire, and don't hire someone you don't trust.

I'd say there are two things to figure out:
1) the separation between a joist and its support may indicate some overall movement in the structure. An engineer needs to visit the building to see if there is any other evidence to support this or perhaps conclude that it's related to wood shrinkage or something else.

2) There's some doubt about how the sheathing is fastened to the furring* and how these pieces are fastened to the underlying framing. If you see a nail poking through, it doesn't mean that a nail wasn't also placed correctly. If you don't see a toe-nail, there could be one on the other side, which may be sufficient. In my opinion, this evaluation and work would be done from the top, so you won't know really the extent of the work that's necessary until you strip the roofing and examine it.

*furring is an imprecise word for these pieces, but someone can remind me of a better term.

Trust, but verify, as Regan said. I’m an engineer also, by the way.

There has been some uneven settling and heave of the building foundation which was investigated about eight years ago. So perhaps that has something to do with the separation of the joists from the hangers. But the report says that at that time it didn’t appear to be significant enough to cause structural damage to the building.

The consultant told me that there is supposed to be a toe-nail on both sides of the cross-strapping.

Stripping the deck plywood off would be extremely expensive and is what I’m trying to avoid if at all possible, and would only be done at the time of membrane replacement anyway. I understand that an inspection of the roof structure would involve cutting some openings in the deck, taking a look at the structure, then sealing the openings. But this will also be a few thousand dollars to do.

jfklein · Dec 12, 2022

Enable said:
As someone who used to work with condominium boards on a daily basis, I would strongly caution you against using the opinions of an online internet forum to sidestep the recommendations in a formal report; especially since those recommendations pertain to life safety, and the Board of Directors (BOD) commissioned the consultant to perform the work. YOU, the OP, and the rest of the BOD have a fiduciary duty to your members and are legally obligated to behave in a prudent, responsible manner.

If something should happen, and it came to light that you made the deliberate decision to not act on the recommendations of an official report, you personally will be held responsible. You will not be protected by the corporate structure. Additionally, it is a near certainty that the condominium insurance carrier would claim you were grossly negligent and rightfully deny you coverage, which means all legal expenses and restitution are on your dime. I've seen it happen on more than one occasion, and the outcome was devastating for the board members.

While the building has stood for some time, and it is probably unlikely anything too bad will happen in the foreseeable future, is that a risk you personally want to take? You are talking about the cost of an investigation, which might amount to a few thousand plus minor repairs. Do what the report recommends and sleep well; it's not worth it for a couple hundred out of your pocket.

My understanding is that it would cost something like $100,000 if the roof deck needs to be removed and repairs made to the underlying structure. Although, this is something I need to clarify with our consultant.

jfklein · Dec 12, 2022

JStructsteel said:
Its 42 plus years old. Are there major signs of impeding failure, or extensive damages to finishes?

None.

Are you or the homeowners prepared for the ramifications of a engineers report?.

If it costs $100,000 to fix, we are not prepared.

Would this report spill over to other Condos in same development if the local building official caught wind of it?

There is only one building in our development.

Start with the engineer report if concerned still.

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Do You See Any Construction Problems With This Roof Framing? 6

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