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Does code require identifying wood grades of existing structures?

Does code require identifying wood grades of existing structures?

Does code require identifying wood grades of existing structures?

(OP)
I received comments from the Daly City Building's Division in California and one of the comments is "Provide documentations and evidence to verify the lumber grades and species for the original construction (IBC/CBC 2303.1.1). All I am doing is installing a 4x4 skylight that requires cutting one truss member in a small 60yrs old residential house. Every other engineer and plan checkers in other jurisdictions I asked said they've never been asked or asked to provide documentations on the lumber grades of an existing house. Is it even legal for them to request this? I would like to hear your feedback. Thanks.

RE: Does code require identifying wood grades of existing structures?

They can ask for anything. And cutting one truss member makes the truss no long valid to transfer loads unless it is analyzed... and a 4' skylight may require cutting two consecutive trusses unless the skylight is more like 3'10"x3'10"

RE: Does code require identifying wood grades of existing structures?

I've been asked to provide verification of lumber grades when we have needed to assume a specific grade (i.e. D.Fir SS instead of D.Fir No. 2). However that was only twice it has happened and both were commercial projects in 100 year old warehouses.

RE: Does code require identifying wood grades of existing structures?

How would one go about identifying the wood species? Call the local lumber yard and ask which wood is most prevalent? Or just be extra-conservative in the design. You can estimate the grade of wood by looking at it.

RE: Does code require identifying wood grades of existing structures?

In my cases we had a company come out and take samples and test the lumber to ensure it met or exceeded the design values we were using. They had a professor (specializing in wood) from the university consult when they needed an expert opinion.

RE: Does code require identifying wood grades of existing structures?

Jayrod, that's probably overkill for the project the OP is describing, but it is good to know that option is available for larger projects.

RE: Does code require identifying wood grades of existing structures?

Definitely overkill. Expensive too. Like I said it was only to prove we had stronger lumber than the city was willing to accept without testing. And it was a huge commercial remodelling and the reinforcement costs would've tanked the whole project.

In the OPs case we just assume a low enough grade that the City doesn't question it. If you have some reasonable assumptions I've found them to be reasonably accomodating.

RE: Does code require identifying wood grades of existing structures?

Per the 2010 CBC


"3401.4 Building materials. Building materials shall comply with the requirements of this section.

3401.4.1 Existing materials. Materials already in use in a building in compliance with requirements or approvals in effect at the time of their erection or installation shall be permitted to remain in use unless determined by the building code official to be dangerous to life, health or safety. Where such conditions are determined to be dangerous to life, health or safety, they shall be mitigated or made safe.
3401.4.2 New and replacement materials. Except as otherwise required or permitted by this code, materials permitted by the applicable code for new construction shall be used. Like materials shall be permitted for repairs and alterations, provided no hazard to life, health or property is created. Hazardous materials shall not be used where the code for new construction would not permit their use in buildings of similar occupancy, purpose and location.
3401.4.3 Replacement, retention and extension of original materials. [HCD1] Local ordinances or regulations shall permit the replacement, retention and extension of original materials, and the use of original methods of construction, for any building or accessory structure, provided such building or structure complied with the building code provisions in effect at the time of original construction and the building or accessory structure does not become or continue to be a substandard building. For additional information, see Health and Safety Code Sections 17912, 17920.3, 17922(d), 17922.3, 17958.8 and 17958.9."

and

"3401A.4 Building materials. Building materials shall comply with the requirements of this section.

3401A.4.1 Existing materials. Materials already in use in a building in compliance with requirements or approvals in effect at the time of their erection or installation shall be permitted to remain in use unless determined by the building code official to be dangerous to life, health or safety. Where such conditions are determined to be dangerous to life, health or safety, they shall be mitigated or made safe.

3401A.4.2 New and replacement materials. Except as otherwise required or permitted by this code, materials permitted by the applicable code for new construction shall be used. Like materials shall be permitted for repairs and alterations, provided no hazard to life, health or property is created. Hazardous materials shall not be used where the code for new construction would not permit their use in buildings of similar occupancy, purpose and location."

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

RE: Does code require identifying wood grades of existing structures?

If one or two trusses are to be cut, two things must be checked:

1. The cut trusses are properly supported at panel points at each end of the opening.

2. The adjacent trusses are adequately reinforced to sustain the additional load from headers supporting the cut trusses.

Knowing the grade of the existing lumber does not help very much in assessing the capability of the existing trusses to carry additional load. Their capacity is more likely to be governed by the connections than by the grade of truss members.

BA

RE: Does code require identifying wood grades of existing structures?

Well, I would assume a local likely species and grade for the time and area and use 2 grades less than that.

I have had to do that here for more than one municipality to get it to pass for older structures without sampling and lab testing.

I would certainly analyze the connections using the lower stress grade values to be conservative without formal testing.

Mike McCann, PE, SE (WA)


RE: Does code require identifying wood grades of existing structures?

(OP)
I assumed Douglas Fir Larch No. 2, which is conservative, and analyzed in Risa 3D. I am also doubling up the affected chords. But even without doubling up, it is still within code limits with one truss cut. The design is very conservative as I explained in my submitted calcs. The plan check comment (among many other ridiculously difficult comments) is:
"Provide documentations and evidence to verify the lumber grades and species for the original construction (CBC 2303.1.1).

How much does it cost to have someone grade and certify the wood? Where can I find this service?

RE: Does code require identifying wood grades of existing structures?

Have you tried calling the plan reviewer directly and discussing the comment? I've found most plan reviewers to be pretty accommodating to you on the phone if you have a reasonable request.

RE: Does code require identifying wood grades of existing structures?

Jacky89...you gave the age of the structure as 60 years. That would put construction in the mid 1950's. If the trusses were pre-fabricated and have metal truss plates, then it is likely that there are grade stamps on the truss members. Most pre-fabricated trusses are going to have No.2 or better top and bottom chords and can have No. 3 diagonals, usually of pine or fir.

The West Coast Lumber Inspection Bureau has been grading lumber along the west coast since the 1920's, so it is likely that your lumber is grade stamped.

Here's a link to their website:

WCLIB

The building department has every right to ask for this information, particularly since you are modifying a structural component. You will not likely be able to get any good documentation of the lumber properties unless you can find a grade stamp and photograph it. This is all assuming you have no original plans.

RE: Does code require identifying wood grades of existing structures?

(OP)
The truss were not prefabricated and uses plywood gusset plates.

It's hard to imagine the building department would ask this every time someone makes any change to a small single family house. My analysis assuming conservative DFL No.2 results in a lot of remaining capacity. Most old structures here use lumber equal to No. 1 or better.

If they require evidence and documentation for grade of lumber for all existing residence in this city, then no one will be able to do any kind of structural work regardless of how minor it is. The residents are also generally low-income in this city.

RE: Does code require identifying wood grades of existing structures?

But it is California, after all.

RE: Does code require identifying wood grades of existing structures?

Grading lumber for your purposes is not that difficult. You can get a copy of the grading rules for your area and do it based on the rules. Call the grading bureau that does the grading for your area and talk to them. I gave in my previous post a place to start.

Yes, this takes time but you'll learn something.

RE: Does code require identifying wood grades of existing structures?

(OP)
I know several experts at grading lumber. But the issue is they are not a lumber grading agency and would not comply with this code section.

2303.1.1.1 Certificate of inspection. In lieu of a grade
mark on the material, a certificate of inspection as to
species and grade issued by a lumber grading or inspection
agency meeting the requirements of this section is
permitted to be accepted for precut, remanufactured or
rough-sawn lumber and for sizes larger than 3 inches
(76 mm) nominal thickness.

RE: Does code require identifying wood grades of existing structures?

(OP)
I checked with the structural plan checker and he said it must be graded by a certified lumber grading agency. I asked him has anyone been able to install a 4x4 skylight in the city and he said no. He said no one will be able to prove to him the unknowns in an existing truss system. He also said the lumber grading agency will most likely not come to my house to grade the lumber.

Now I really see why the house prices in Daly City are not going up like the cities around it. It is near impossible, if not impossible, to get any kind of structural permits. Even very simple work that would be over-the-counter permits at neighboring cities will have to take months to get in this city.

RE: Does code require identifying wood grades of existing structures?

Would it be possible (I didn't say practical) to insert a new truss or beam each side of the skylight such that you are not relying on the existing trusses?

BA

RE: Does code require identifying wood grades of existing structures?

What a silly situation... We offer lumber identification (not grading) services, but I do not do this work. It is not as simple as looking through a book and matching photos. One of our partners is a Forest Engineering grade from UNB and actually qualifier to do this work. Beyond that we simply apply the lowest grade of lumber available at that time. We have yet to have any problem with any city using this approach; While I don't know the jurisdiction in question, their interpretation of your code/requirement seems unreasonable.

Why not sister the cut members with a new set of rafters, effectively turning the old timber into packing?

Oh, and as for identifying your own lumber, just try to think of what your would say in your defends if you got it wrong: I read a book your honour. Not quite then equivalent of having stayed at the holiday inn, but I think you get my point...

RE: Does code require identifying wood grades of existing structures?

(OP)
I talked to the structural plan checker who gave these comments. He said I would need to hire a certified grading agency to grade the wood but he doesn't think I will be able to find one that will be willing to come to my house for such a small task. He said the other option would be to cut out a piece of wood from the truss and send it to the lab for testing, which is also unpractical as that would damage the truss, and he will probably make me redo my whole roof. I asked him has anyone been able to put in a 4x4 skylight in a trussed roof system and he said many engineers have attempted a permit before but none has ever gotten a permit from him. Basically he said there's no way for it to be done without tearing out the roof and rebuilding new trusses around the skylight. If I knew this building department was this difficult, I would have never wasted 2+ months on this. I bought the house in May and I still haven't been able to start construction. I'm paying mortgage, property tax, insurance, and utility bills on the new house and still renting another place waiting for the whole permit/construction process to be over with so I can move in. My plan checker friends at all the other jurisdictions around Daly City said the work I'm doing is so simple, I would have gotten an over the counter permit. It sucks thinking that I'm paying such a hefty price for being a good law abiding citizen.

RE: Does code require identifying wood grades of existing structures?

What a jackass. You can't go over his head?

RE: Does code require identifying wood grades of existing structures?

Also the idea that the timber must be specifically graded is dumb. Once you've identified the species, an assumption of the lowest (or even most common) grade is perfectly reasonable so long as you are also upgrading... Which you likely would be.

I say jgailla is right, but I'd propose going political. Your city councilor does not like trouble any more than the next politician. Building Officials are not Gods, and have a very hard time enforcing more strictly than the common practice demands when placed under a microscope of political pressure.

RE: Does code require identifying wood grades of existing structures?

(OP)
I can't risk going to City Council as that will take too long and risk anger the structural plan checker and I will never ever be able to get a permit. I am doing so little work to my house, I just want my permit so I'm not paying rent and mortgage at the same time and run into a foreclosure as I am already dangerously low on money. I might even have to just cancel my permit now as I am still waiting. I asked the structural plan checker if he still needs to review it because there's obviously no more structural work as I am no longer cutting any truss members. I told him my hardships and that my family will be flying over to visit me next month because I told them I will have a place for them to stay when I first bought the house almost 4 months ago. He told me in anger that it's up to him to determine whether there's any structural work and that he won't look at my resubmittal until he is done with others that are ahead of me and he's angry I'm wasting his time for talking to him. He was talking like I am being super selfish trying to cut in line when all I'm asking is if we can stop wasting both his time and my time since there's no structural work and he doesn't need to review them, which is a very reasonable question. I am about to go bankrupt and my family won't have a place to stay when they come. So yes, Daly City plan checkers pretty much are Gods and completely unsympathetic to hardships of the lowly humans.

I so regret buying a house in Daly City. I have heard tons of horror stories about the building department and warned not to buy in this City but I always thought it was exaggerated until now. sigh...

RE: Does code require identifying wood grades of existing structures?

With sympathy to your situation, I think you have little choice but to go political. The type of small mindedness that this plan checker has now shown (taking you at your word for the gist of the conversation) means they are just as likely to purposefully take longer in reviewing your work out of spite.

In terms of the technical situation, it is an unreasonable request. In terms of client service this is now completely unreasonable as well, but I don't see how anyone here can help you.

Good luck.

RE: Does code require identifying wood grades of existing structures?

I would be talking to my client and recommending changing the skylight configuration so that trusses do not need to be cut. If the trusses are 24" on center, 2 skylights that are 22.5" x 24" or something similar might be just as well.

By the way I do not think it unreasonable for the building official to require an analysis and lumber grades are known to vary widely in truss construction.

RE: Does code require identifying wood grades of existing structures?

I feel it is unreasonable for them to require it if you are assuming the lowest grade of material in use at the time. If you require a higher grade in order for your calculations to work then yes I agree that professional identification and grading is required.

RE: Does code require identifying wood grades of existing structures?

Jayrod is bang on: It is relatively easy for a qualified individual to identify he species of wood, and as it would all have been graded, an assumption of the lowest available grade available at the time of construction is completely reasonable.

I have yet to see a timber member fail at the calculated strength in testing. Timber is very conservative and robust by nature. True, trusses make the most of the permitted strength, but we are talking about a situation where the client is open to upgrade and so the precise strength is not required.

The building official is not being reasonable, they are being obtuse and pedantic. I suspect the combination is an actionable tort, but it would be an uphill battle and our OP is already in a delicate position.

RE: Does code require identifying wood grades of existing structures?

(OP)
The existing wood used in these structures are well known by engineers here to be no. 1 or better grade and visual inspection of the truss member shows that it is very hard sturdy wood in excellent condition. But he will not allow assumption of even the most conservative wood. The structural plan checker will not allow assuming the most conservative wood grade. He mandates a certified lumber grading agency to grade the wood or cutout a piece of wood to send to a certified lumber testing laboratory for testing. Both solutions are completely not practicable. But he is the law and we must obey. I don't have money or time to find justice. It is hard to imagine how much power a Building Official can have on the ordinary home owners in the city.

RE: Does code require identifying wood grades of existing structures?

Is there not someone at their office that does the larger type project plan checking (i.e. commercial)? If so, try calling them, they would have started in the residential review sector and might be able to give you some better direction than this arse-hole

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