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Structural Inspection of Residential
4

Structural Inspection of Residential

Structural Inspection of Residential

(OP)
Perhaps several of you have conducted structural evaluations and/or inspections of residential construction. This subject is of interest to me in light of recent events highlighted on previous posts.

A couple of questions I would like to present here:

1.) Should there be general mandatory inspections required for structural elements of residential structures, regardless if they are privately owned or rented? How often should these inspections occur?
2.) In lieu of general mandatory inspections, should there be mandatory inspections of specific structural features of residential structures - and if so - what specific features should be inspected? And how often?

In absence of such required inspections, owners are left to their own judgement as to when to call for an evaluation. Usually, they do not call until disaster strikes. We get calls now and then from homeowners insurance companies for structural evaluations of residences that have recently been damaged. We also get calls from time to time from realtors regarding residences currently under escrow that have had a general inspection but required a "specialist" - in this case, a licensed engineer - to answer specific concerns.

Is it sufficient to leave the homeowner to his/her own devices, not really knowing when a certain situation could be dangerous, even life-threatening?

What are your thoughts on this?

Richard L. Flower, P. E., LEED Green Associate
Senior Structural Engineer
Complere Engineering Group, Inc.

RE: Structural Inspection of Residential

rlflower,

When I bought my house ten years ago, my home inspector was a Certified Engineering Technologist. I don't know what his actual training was. My insurance company was primarily interested in my electrics. Nobody in my neighborhood gets building permits, and there are lots of home handymen. The city is not aware of my roofed front porch or of my back room. Both of these extend across several townhouses. I am sure you can image the possibilities.

Having said that, I don't see any marginal structures like cantilevered balconies or porch roofs. Home handymen may overrate their skills, but they don't aggressively design crazy structures. My neighborhood does not lend itself to tall rear decks. Quite a few years ago on Toronto, somebody worked on his basement and undermined the townhouse next door. I don't know how common this is.

--
JHG

RE: Structural Inspection of Residential

(OP)
Is it a requirement for realtors to have a general inspection of any given property during escrow? Perhaps this would be a state law?

Richard L. Flower, P. E., LEED Green Associate
Senior Structural Engineer
Complere Engineering Group, Inc.

RE: Structural Inspection of Residential

To pre-qualify my response, I don't know the first thing about how the residential world currently works -- except for my limited experience in buying a house myself.

That said, proposing mandatory structural inspections seems ludicrous to me. To make a long argument short, I don't see the market bearing the proper cost of having a qualified and experienced engineer inspecting every new home for structural issues (probably requiring several visits from the engineer per home). I can't imagine this sort of inspection being easy. How often on this forum are details of wood-frame construction brought up and debated for several pages before a consensus is reached about a certain analysis approach being kosher or not?

I suspect that with the cost of a robust inspection program, there would quickly be a number of fly-by-night low cost operators out there providing structural inspections without the expertise or experience you envision. Give it a few years, and my guess is that the number of structural life-safety issues being caught by such a requirement approaches nil.

My opinion aside, do code inspections on new construction currently check for structural issues as well as your typical plumbing/electrical/fire items? I honestly don't know.

RE: Structural Inspection of Residential

This is more of a policy discussion than an engineering discussion. The implications of requiring structural inspection of new residential construction is daunting, if not completely infeasible. Requiring inspections for existing structures is probably impossible.

Refer to my post in the Balcony Collapse in Berkeley, CA thread for my thoughts on improving construction quality and/or the requiring of inspections. I believe the only way to make any actual progress on those ideas is to approach it from the insurance side of the equation. They are the ones ultimately footing the bill for issues so they'd be the most effective route for change. Piling more responsibility, policing duties, and documentation on governmental agencies won't work. If insurance (for contractors, designers and property owners) would offer discounts on rates for documented inspections similar to auto insurance rate discounts for attending driver safety courses there might be some adoption of engineering inspections of buildings.

RE: Structural Inspection of Residential

rlflower, to answer your question about inspections during escrow, I don't know of any requirement, although it seemed to be standard practice when I bought my home.

That said, this inspection was not required to be by any specifically qualified person. Additionally, if we're talking about inspections of existing properties, I'd imagine the effectiveness of a structural inspection is even lower without substantial access to the structure. And I can't imagine homeowners agreeing to having their drywall torn out so the engineer can take a look (except for the case where a problem is already evident).

RE: Structural Inspection of Residential

(OP)
Here in California at least, there are sufficient inspections and observations conducted during construction as required by code. I tend to agree with Lomarandil regarding inspections; allowing the owner to make their own judgement as to when to call for an inspector is perhaps best. What remains, then, is how to educate the general public regarding residential safety and general maintenance.

Is it possible that an owner (not any specific owner) could be held liable for neglectful maintenance?

Richard L. Flower, P. E., LEED Green Associate
Senior Structural Engineer
Complere Engineering Group, Inc.

RE: Structural Inspection of Residential

When most everything is covered up, and special equipment would have to be brought into each privately owned residence each time, I do not think this would fly just based on economics.

I too am concerned for safety, but I think that the average homeowner would balk at 1 to 2k every 5 years or so. Upon sale, yes. It should be mandatory periodic for rental and commercial properties too.

Mike McCann, PE, SE (WA)


RE: Structural Inspection of Residential

1) No
2) No

I don't like mandatory. I'm getting more libertarian the longer I live.

RE: Structural Inspection of Residential

1) Realistically (in Canada at least) field level review of any Part 4 design is required by the designing engineer or any other suitably skilled person. If you want to try to actually enforce that - good luck. As-is (I had a meeting with our City permits department very recently on this very matter) it is left to the engineers discretion - if you think a monkey could do it right, no inspection; if you think they are capable of screwing it up - inspection.

2) Get real, first you have to sell it to the City. They are going to come back at you and ask where the money to oversee such a mammoth undertaking is going to come from. Second you have to explain it to the homeowner, which is going to be neigh impossible. Yah - multistory RC&Steel structures should be inspected, but if you are saying their should be a regular structural review of every townhouse, bungalow and 4-Plex people are going to call it exactly what it is - a make-work, money grab. No one is just going to swallow the cost of paying an engineer or ET $600 to crawl around there house, and possibly throw a big 'Do Not Occupy' sticker on the door at the end of it.

People are no-doubt going to tie this back to the balcony collapse - a regular inspection wouldn't have even caught that! A closed in balcony floor, only accessible in-suite. Totally independent of the superstructure and would not have been inspected in a regular structural review.

RE: Structural Inspection of Residential

rlflower,

My house was inspected because my insurance company insisted on it. Some friends of mine bought in downtown Toronto. When they asked about inspection, they were told the house would be sold before the inspector got there. In other words, "PFO".

--
JHG

RE: Structural Inspection of Residential

drawoh,

Typically we get asked to do inspections when there are modifications to the house other than those the city has paper on. If the previous reno was covered by a DP, BP, ext... and the file is closed - sale w/o inspection. If the drawings don't match the as-is layout then they call is in.

RE: Structural Inspection of Residential

Property transactions vary a lot with location. Where I am, if a house is sold by negotiation, the purchaser normally makes the sale conditional on acceptable building and termite inspections. But if sold at auction, it is caveat emptor.

RE: Structural Inspection of Residential

rlflower,

My inspector tested all the wall sockets he could get at. He pulled out the plastic fascia and noted the type of wiring. About half of my wall sockets were wired incorrectly. We did not see any knob and tube. My insurance company wanted to know how old the wiring was, and he claimed it was less than twenty five years.

He told me I would need a new roof in around seven years. He was right. He told me that it was normal for my living room ceiling to sag, given the age of my house. Now that I understand how tile ceilings work, I don't understand why someone would apply stucco to one.

When you inspect a house that has people living in it, you have limited access to stuff. If it was me doing the inspection, I would make it very clear that I inspected only the stuff I could get at. All it takes is for the tenant to put a rug over the cantilevered balcony, and some lawn furniture on top of that.

--
JHG

RE: Structural Inspection of Residential

2
The fact of the matter is that, other than decks, houses are pretty resilient. I have never witnessed any portion of a house collapse in my 24 years of residential work. Seen plenty of sagging, however.

RE: Structural Inspection of Residential

In this neck of the woods, home inspections of existing homes are only called for by the lending agency, prior to underwriting the mortgage. Cash sales do not get mandatory inspections, though many smart buyers will require one prior to closing. If they even see it at all (or are smart enough to recognize what they are seeing), the home inspectors around here will usually record anything they suspect is structurally deficient, and recommend an independent inspection by a registered engineer or architect. Fortunately, the termite control guys, who really have some cost liability on the line, tend to really look at the structure carefully, and they often see items missed by the home inspector. Thank God for them as a backup resource. smile2

Thaidavid

RE: Structural Inspection of Residential

Honestly, I'm of the opinion that as long as the residential code is prescriptive while also saying "provide a complete load path", I wouldn't know what to expect. With residential I feel like you follow a prescriptive set of measures that don't consider diaphragm elements, shear wall design, etc. and then you put your head in the sand at the end and say that'll work. Granted, except in the most extreme cases it seems to work.

In summary, I think the residential code needs a rehab before any true inspections are required. I don't think a house in my state would meet the commercial building code.

But it's not all doom and gloom. Houses have a good track record and we all hedge our bet somewhere. Think about this, no code really designs for tornados, and yet they happen. So it's about an acceptable level of risk. If you think about it too, car accidents happen and people die, and yet we still build roads. It's because the value added by roads exceeds the risk taken. Same way with houses. Let's say you had to provide a true complete load path. Well, good luck selling any existing houses. And then all these other new houses people want to build that have more jut-ins and outs than a coloring book maze.

I think sometimes we as structural engineers get too pie in the sky with theory and forget that even electrical conduit and ductwork add stiffness to a building/house. Point is, I don't think the risk is high enough that the extra cost is warranted. You might be able to buy a code approved house but can't afford to eat. Just my opinion though.

RE: Structural Inspection of Residential

I think that anything that isn’t at least thrice redundant should be inspected three times to provide some redundancy to the system. And, when we once get things a little more codified, every conceivable condition in the universe will be covered in such convoluted and conflicting detail that nothing can possible be built to code. Problem solved. The AHJ will be the organization or deity we pray and bow to, even more so than we do today, and for no better reason. If we can just get the code complex enough, any damn fool will be able to do anything, without even thinking, certainly without any need for engineering judgement or experience. As for working with insurance companies on some of these issues and problems, one would think that that might have some merit, until one thinks about how the insurance companies work and keep their books. The agent wants his/her commission on premiums, so mostly they care about selling lots of insurance. Hell, they’ll insure almost anything as long as the premium gets paid. Sometimes some of the crap that they insure falls down or fails, for all kinds of reasons. Then they pay a claim, and promptly raise the premiums to cover this payout and add a little more cushion and profits to their bank accounts. The upshot is that WE all pay the bill and most anyone who might bring some control to this mess doesn’t give a damn, they’re insured, so they don’t really have to care or think about the best (a better) approach. I’ve had this conversation a number of different times, after insurance companies retained me to help them figure what went wrong and who was at fault. I’ve said to them that I would have advised against insuring this situation, this structure if they had asked me in the first place, for the exact reasons which caused the problem which we are now facing. And while, what I said above about the insurance business is not an exact quote of what they answered, it is the gist of what their answers and shrugged shoulders suggested. Just part of doin business.

RE: Structural Inspection of Residential

Thank god I can finally put my X-ray vision to use.

I had a home owner request this. They wanted to make sure their 30 year old house was structurally sound - no specific concerns. I told them that I could come out, look at what I could see without opening anything up and give them a stamped letter saying that the few things that I could see were / weren't ok. I gave them a fee of twice what a standard home inspection cost.

I did not get the job.

When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.

-R. Buckminster Fuller

RE: Structural Inspection of Residential

@Manstrom;

I get this "structurally sound" request al the time.
How do we define "structurally sound"?

RE: Structural Inspection of Residential

Seems like a lot of liability to say that an existing house is "structurally sound". The amount of time required to be sure of this would make an home owner balk at the price. Not only that, but a lot of residential framing is prescriptive design and doesn't really calc out which is something the forum talks about from time to time. A lot of roofs have been standing for 100 years (2x6's @ 24" oc anyone?), yet don't calc out. How do you put your liability on that?


I thought of becoming a home inspector on the side for some extra cash. I looked into how to get certified, pretty simple process. Pay a membership fee, get 100 hours experience, and take a test. Bam, certified.

I've seen some catastrophic failures of homes/garages for insurance companies. But it's always something the homeowner knows about and neglects.


RE: Structural Inspection of Residential

Different rules, different design perspective, no consistency....that's residential.

Residential inspections during construction vary all over the board, as do commercial inspections. Some are good...some not so good. Because of the speed with which residential construction happens, the inspections are often cursory with respect to structural items, usually hitting the high spots like wind ties, foundation attachment and general framing to see that headers are there, corners are framed correctly, trusses "look" ok, etc. They pay more attention to plumbing and electrical. They do little or no waterproofing inspection including roofs.

As for real estate transaction inspections, those are driven by either insurance requirements, lender requirements or both. I know of no states in the US having mandatory transaction surveys. Some states require certification of home inspectors. I've heard that there are actually states that will not accept an engineer's inspection report unless he is also certified as a home inspector. Ridiculous. As others have noted, the requirements for home inspection certification are not that difficult. I know one here locally who became certified shortly after retiring from the US Navy as a pilot. My guess is there is little wood framing in an airplane these days.

The "structurally sound" term comes up a lot. The thing we have to guard against is some legislative body defining what "structurally sound" means. We've already had them, in Florida, define "inspection for fatigue" in amusement rides, they've defined "sea walls" but not retaining walls adjacent to any other water body (like every one of them around retention/detention ponds), and various other loosely and poorly defined terms that we then have to spend an inordinate amount of time explaining to non-technical people and others what the real impact is. Waste of time.

In some states, residential structures are not required to be designed by an engineer. Bad move.

RE: Structural Inspection of Residential

My inspection of my house focused on the floor being too close to B vent pipe for the exhaust pipe for water heater. keep in mind, it was built this way.


Not a think was mentioned about my retaining wall being out of plumb (failed) by about 6".

House inspections are a joke.

Hire an engineer if you want a thorough inspection of the structure.

RE: Structural Inspection of Residential

Ron, in my area it's not required to have a stamp from an architect or engineer to build a residential house. This was surprising to me. Anybody can draw up plans and have them approved for one and two family dwellings.

RE: Structural Inspection of Residential

Same with my area as long as it meets prescriptive requiements

RE: Structural Inspection of Residential

jrisebo, home inspectors (in Florida) are prohibited from doing any structural inspections (they are not engineers).
Engineers can evaluate (inspect)systems under there area of expertise.

Residential structures engineering requirement have been influenced by builder trade groups to not require engineering.

RE: Structural Inspection of Residential

Home inspectors should still be able to recommend hiring a structural engineer to investigate when something in the house looks sketchy.

RE: Structural Inspection of Residential

Quote (Ron, in my area it's not required to have a stamp from an architect or engineer to build a residential house. This was surprising to me. Anybody can draw up plans and have them approved for one and two family dwellings. )


Same as in my area.

Meanwhile the Residential code says
"The construction of buildings and structures in accordance with the provisions of this code shall result in a system that provides a complete load path that meets all requirements for the transfer of all loads from their point of origin through the load-resisting elements to the foundation."

Then the next statement (prepare to bury your head in the sand):

"Buildings and structures constructed as prescribed by this code are deemed to comply with the requirements of this section."

In between those two sentences is an assumption that the code provides a complete load path. I don't buy it, but the track record of houses is pretty good. I just feel like the first statement is very misleading. I feel as though the residential code should come clean and say it's a prescriptive method. This half-engineered, half-prescriptive is why I stay away from residential work.

PS - I'm not all negative about the IRC, I don't know what a better solution would be, I just don't think that those statements are accurate together. I think they are misleading at best, and it puts engineers in an awkward spot when reviewing residential structures that clearly don't have a complete load path, but were approved to be built.

RE: Structural Inspection of Residential

My opinion is that the designer should do the inspections. In lieu of that the insurance companies should have inspectors.
The government inspection process is too corrupt, which is why I left the field after 16 years.
The contractors own the commissioners who control the major who controls the building official.
I can tell you guys that 15 % of inspectors look at all of the structural details and get them enforced.
I failed a contractor for missing 60% of the nails at an osb splice plate designed for uplift and shear.
The boss came out to the job and was on the contractors side. Then the engineer rolled over and said those nails
didn't matter if there were 10 nails above and below the splices IN the side studs. That was not on the plan.
So you see the inspector is attacked on all fronts, and fights a losing battle. A sane person eventually gives up.
Now on to the matter of houses being engineered.In many cases it is not possible to do without steel, which a contractor won't use.
Many Florida counties required engineered wind load design on houses ( which is against State Statute). This puts the engineer in a lose-lose position for it can be proven on many houses that there are no load paths.
I have seen double garage doors with 12" walls between them and called out as shear walls.The above comments are correct in that there are unknown load paths and mechanisms in a house than engineering practice knows, uses or comprehends.
A wall corner functioning as an angle or channel is stronger than a shear wall.



Inspector Jeff

RE: Structural Inspection of Residential

Quote (ChiefInspectorJeff)

Now on to the matter of houses being engineered.In many cases it is not possible to do without steel, which a contractor won't use.
Many Florida counties required engineered wind load design on houses ( which is against State Statute). This puts the engineer in a lose-lose position for it can be proven on many houses that there are no load paths.
I have seen double garage doors with 12" walls between them and called out as shear walls.The above comments are correct in that there are unknown load paths and mechanisms in a house than engineering practice knows, uses or comprehends

??? This makes no sense. Please explain.

RE: Structural Inspection of Residential

Which part?

Inspector Jeff

RE: Structural Inspection of Residential

Quote (ChiefInspectorJeff)

Now on to the matter of houses being engineered.In many cases it is not possible to do without steel, which a contractor won't use.
What steel are you talking about? If straps, contractors have no issue with installing straps. If tension rods, same thing...however, they don't always install either properly.

Quote (ChiefInspectorJeff)

Many Florida counties required engineered wind load design on houses ( which is against State Statute). This puts the engineer in a lose-lose position for it can be proven on many houses that there are no load paths.
How is this against state statute? There are load paths on/in every structure. Residential structures are no different.

Quote (ChiefInspectorJeff)

I have seen double garage doors with 12" walls between them and called out as shear walls.The above comments are correct in that there are unknown load paths and mechanisms in a house than engineering practice knows, uses or comprehends
Competent engineering practice can clearly define the load paths and such is not difficult to comprehend by an experienced engineer.

Please explain your comments so that we might better understand what you mean by them. They are not helpful as stated and seem to have no basis in engineering or fact.

RE: Structural Inspection of Residential

Quote (ChiefInspectorJeff)
Now on to the matter of houses being engineered.In many cases it is not possible to do without steel, which a contractor won't use.

What steel are you talking about? If straps, contractors have no issue with installing straps. If tension rods, same thing...however, they don't always install either properly.
I am talking about steel columns required for overturning moments under second floor shear walls that occur over garages and are offset 12' from a shear wall.

Quote (ChiefInspectorJeff)
Many Florida counties required engineered wind load design on houses ( which is against State Statute). This puts the engineer in a lose-lose position for it can be proven on many houses that there are no load paths.

How is this against state statute? There are load paths on/in every structure. Residential structures are no different

Florida statute does not require engineering certification on residential and certain commercial jobs.I did not mean engineering is against statutes.
.Try engineering some houses per ASCE and you won't get anymore work.

Quote (ChiefInspectorJeff)
I have seen double garage doors with 12" walls between them and called out as shear walls.The above comments are correct in that there are unknown load paths and mechanisms in a house than engineering practice knows, uses or comprehends
:. Alluding to the fact raised above that there are other untested load paths in houses( electric wiring was mentioned.) I noted that the corner configuration of a wall could be construed to be a channel or angle analogy,imparting more strength to the structure, but is not done according to conventional engineering methods.

Competent engineering practice can clearly define the load paths and such is not difficult to comprehend by an experienced engineer.Many engineers do not know where the load paths are especially with diaphragms and shear walls.They leave out drag struts, chords, etc.

Please explain your comments so that we might better understand what you mean by them. They are not helpful as stated and seem to have no basis in engineering or fact.

The basis in fact is I have done 68,000 inspections and plan review and have seen all of this.
Thus many houses are not engineered to ASCE or codes because to do so would be cost prohibitive as mentioned in above post.They are sealed but do not meet the standards; that is the lose-lose.
One last example.Gable end bracing is attached to the webs of trusses. Was that plate designed to transfer the load to the sheathing? In fact the Fl. engineering board came out with a letter prohibiting the use of x-bracing in 2001.
I have many more examples.
I hope that cleared up the issues regarding structural inspections of residential.

Inspector Jeff

RE: Structural Inspection of Residential

Steel columns at overhanging shear walls? Usually straps or HD'S with 6x6's. Why? Is this a soft story condition?

Mike McCann, PE, SE (WA)


RE: Structural Inspection of Residential

I design houses in Florida on the east coast. I design for all load paths including uplift and lateral from wind. All of the counties we work in have building inspectors to verify all of the structural components. In my opinion the inspectors do a good job since I get calls from contractors all the time for failed inspections. Most of the residential engineers around my area do good job as well. Occasionally I come across a set of really bad structural plans, usually they are from an "out of town" engineer not familiar with the uplift requirements or from an architect who thinks they are an engineer.

RE: Structural Inspection of Residential

NFExp....I practice in Florida as well and my experience is similar to yours with regard to the capability of residential design engineers....thus my questions and comments above. I do mostly forensic work which involves a lot of multifamily, condo and single family residences, including evaluations of the structures. The residential structural design is rarely an issue....more often construction.

RE: Structural Inspection of Residential

Agree on residential design engineers. But in west FL we have many designs that use deem to comply (SSTD 12) or only have Eng on area that don't meet the SSTD. Our inspectors are not as experienced as NFExp has found. The biggest issues I see are load paths, interior load bearing and shear walls and truss point loads.

RE: Structural Inspection of Residential

Aftering working through many residential designs over the past year and half I think that residential designs in this area are thoroughly engineered and inspected. Based on many comments above one would think that residential construction is the bastard child of commercial work but this is not so.

Our local inspector here is very conscientious and careful with both new and remodel work. If the structure is something that does not fit neatly within a prescriptive method that he is comfortable with he turns them over to an engineer and requires a stamped drawing or letter.

With residential work I typically look at the following items for a complete analysis:

Vertical:
Beams
Headers
Posts
Footings
Rafters
Deck Joists
Floor Joists
Uplift

Lateral:

Shearwall (sheathing, chords, connections and holdowns)
Anchor Bolts
Wall Sheathing & nailing
Roof Sheathing & nailing
Stud Wall Check for Biaxial loading

Special situations such as window walls, multi-story, interior shearwalls, girder trusses, highly loaded shearwalls or portal frames require additional analysis and usually another sheet or two of structural drawings.



A confused student is a good student.
Nathaniel P. Wilkerson, PE
www.medeek.com

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