A large percentage of the floors I walk seem “soft” when compared to adjacent rooms within the same home. Some walls concern me when I see moisture or wood destroying organisms in an area of the wall. One home owner told me that she might resurface the floor - I told her that I would be surprised if she did not have to replace the floor joists. (These were not visible and none of these could be visually verified.)
I do not want to be responsible for doing an engineering evaluation of a floor system. I do want to quantify my “feeling” that a floor system is soft. Having walked the exterior perimeter of the home, viewed the floor system “from the bottom up,” often I have an understanding of the nature of the floor system such that I can with some level of confidence guess that one rooms floor ought to be just about as stiff as an adjacent rooms floor. Of course, many times I may not be able to make this assumption. When I can, and I am on the fence as to whether or not it should be reported. I want something definitive that quantifies “seems soft.” My tester will give me a value, say “55.00” in one area (don’t worry at this point how to define the 55.00 - it is just a relative number) but reads 405.00 in areas that should read about the same value. Armed with this data, I then put in my report that I have reason to believe that a Structural Engineer will likely find a problem with this portion of the floor system as the other areas reported ‘stiffness values’ of about eight times more that the soft area.
I have contacted a company that is willing to modify their existing tester for use in the home inspection industry. I now wonder if I might be the only one of us who would find it useful.
For now, let’s assume that the cost of the tester is reasonable, and that its findings are indeed accurate. YOU would:
Use even if other HI’s fear liability issues with its use.
Not use if available
Campaign against its use because you don’t want to invest in another tester.
Campaign against its use because you fear liability issues
Give it a chance to prove or disprove its usefulness.
As an SE called in to do evaluations on framing, as well as doing inspections on residential/commercial buildings, I can say without a doubt it sounds like you are opening up a huge can of worms and probably will end up on a slippery slope with a pit at the bottom.
In addition to far exceeding any HI SOP, what industry standards would you compare those readings to? Is the equipment calibrated to recognized procedures? What is the exact loading on the floor at the time of the inspection/measurements so those readings have meaning? There is also the potential legal issue of keeping a consistent level of inspection for all the systems/components of an inspection.
As an HI instructor also, I understand your delima as to where to draw the line as to calling for further evaluation or not. But there is no simple solution to get a more definitively answer to possibly “flexible” floors short of doing engineering deflection calculations. You should have one or two SE’s you are familiar with in your area that you defer to for evaluations, and I would recommend discussing your inspection procedures with them.
Flexibility of floors is just another item in a very long list of things where experience and working with specialists you may recommend over time is the answer.
Perhaps I am not an SE (Structural Engineer) because I don’t think of things in the way you (or they) do. A Pharaoh once said “build me a pyramid!” (this could have started with "In the beginning A Pharaoh …) Can you imagine all the reasons given why this could not be done? (assume they didn’t mind having their heads separated from shoulders.)
This is not to make light of your thoughts! I have not considered these things. None-the-less I have to assume that if the way I feel about my ‘belly jiggle’ when I walk a floor can predict a problem fairly well, then a light-weight, easy-to-use laboratory prooven tester ought to do it better. Right?
Of course, you are aware that the MOE of a structural component can be determine without the benefit of
“stress tests.” I now realize that in my aforementioned proposal I have used the word “system” when I should have used the word “area.” That is “Floor area” rather than “Floor System.” Would this make a difference?
Let me explain. The marble I now carry in my pocket (thank you Kevin P. Mc Mahon) would take me to the floor’s lowest spot and here the tester would present an MOE value directly below the test - up to 18" depth (or 45.72cm). If I move two feet away and I cannot get a similar reading I have reason to suspect a problem (remember I don’t pull out the tester unless I feel it will tell me something - meaning I have considered the immediate environment.) How about a sill plate? Many times one side of it is exposed and does not look good. My tester will tell me how this spot compares to a spot a foot or six inches removed.
Rather than to say “Why?” I have chosen to say “Why not?”
You can find from my posts to other threads that I shutter at anything that will put my “liability” to challenge. However, I (apparently) have more tolerance for this when it is “MY IDEA.” This is exactly why I put this proposal to our membership - I have chased bad ideas before, i.e., back in 1971 I was going to add a touch-tone memory to a telephone (I knew how to do it) and my friends said “that’s a crazy notion, no one would want it …” and only five years later someone brought the first to market. So, on this one, give me some credit here - I didn’t ask my friends!
Back to the liability thing. Someone within these threads revealed that a Home Inspector was, or is being, sued for a ridiculous amount of money because the inspectors “mold tests” indicated to the a client that his investments in repairs were not needed. This too is beyond the HI SOP but many inspectors offer the service with anticipated risks. If we look at the depth of understanding we seeks, as industry specialist, most of us perform substantially above the standers (but occasionally miss a simple thing.) So why is a CMI needed - or even certification or licensing for that matter? Isn’t it true that if we perform to the level of the SOP’s most of us ‘jack of all trades’ would perform adequately with a “Handbook” and a relatively simple form. **The qualification for a *CERTIFIED Home Inspector ***should **require: 1) a MINIMUM of twenty-years of hands-on ‘Trades’ experiences, and 2) test completion to show command of the Handbook. That is it. **Wisdom is not gained from a book and we don’t want to compete with young folks who are looking for an “easy” job. When we are fifty years of age and are being replaced by the young strong guys, the HI industry utilizes our life experiences in a way not appreciated by employers who need the fast and strong. Why is our door open to the young with insufficient intuition? Age discrimination you say? Then lets consider strength and speed discrimination. Why not?
Okay, back to the point: “the litigious among us.” There is blatant incompetence which I expect to be accountable for. All other things are covered my our contract with our client. Disclaimer, disclaimer, disclaimer… Still not infallible. Maybe some of us just take ourselves too seriously, pretending to place genius before our clients. (There is always someone smarter, bigger, wiser…) This guy should be sued. I have driven the Freeways between the length of New Hampshire to Jacksonville Fl, through all the southern states to Ca, to WA, to Montana, to Colorado. If these are driven at five miles over the speed limit I bet you have a 99.99999999…% chance of NOT getting a speeding ticket for your five miles over the limit. And, similarly, if you do not insult your client and performed an honest home inspection to the best of your ability, I bet you would have equal chance of NOT finding yourself in a court room. Joe Ferry - is this true?
So, in conclusion, the Floor Area test is a simple “relative” test that I would gamble would not put me in a court room and would provide a client powerful information to consider in a home inspection. (I can hear Realtors pounding their collective jaws as I speak.) Yet, if a Realtor is buying a property for his personal investment I bet he would call me rather than is reliable HI that he sends his clients to.
Robert, as a Structural Engineer wouldn’t such a tester be invaluable in your service and potentially save you time during evaluations and reduce the possibility of finding your company in a court room if used appropriately?
(Sorry - lot’s to consider here, appreciate everyone’s help.)
There are established field load tests with ASTM standards that can be done on floor structures, but the cost is far above just having an SE come in to do an inspection and load/deflection calculations.
The problem is that you either need to do calculations, or accurately measure the response of a element/system with a known existing and additional load in order to predict strength and deflection response. It’s just a matter of basic physics and mechanics of materials. Also consider that you need to be careful not to cross the inspection verses evaluation line with structural systems, due to state licensing laws on the practice of engineering (which includes evaluation of structural elements).
Talk to some local SE’s, and possibly some local materials testing labs. There are also some very good research engineers at Lehigh University that you might be able to talk to. But load testing is usually the testing approach, with no other simple solutions.
However I wish you well on you endeavor to build the “better mouse trap” …
[quote=roconnor]
There are established field load tests with ASTM standards that can be done on floor structures, but the cost is far above just having an SE come in to do an inspection and load/deflection calculations.
The problem is that you either need to do calculations, or accurately measure the response of a element/system with a known existing and additional load in order to predict strength and deflection response. It’s just a matter of basic physics and mechanics of materials. Also consider that you need to be careful not to cross the inspection verses evaluation line with structural systems, due to state licensing laws on the practice of engineering (which includes evaluation of structural elements).
Robert,
Thank you for staying with this.
I wonder, from your response it seems maybe I did not make my point or I am not understanding your comments and if you wouldn’t mind, please get me on the same page with you.
Because I am talking about a localized area of maybe three square inches, I am not speaking to the entire floor system. On my other post “Poll: Would you use a floor system tester” I gave a better description of how this is done - I did not mean to create three of four posts but could not seem to get it right.
If you are familiar with MSR Lumber, you are aware that one technology injects electrical impulses into fiber to interpret stiffness (MOE) by measurement of the velocity of the reflected wave. As more dense fiber, excluding compression wood, allows faster propagation time and this “time” correlates nicely to MOE, it would seem that this would work well to identify termite, powder beetle, or rot damage. The software within the tester would compute calculations and a go - no go condition should be possible. Again, this is only for the area immediately below the tester and says nothing about a floor systems functionality as a whole. Different wood species MOE are close enough that to attempt to distinguish between them for our HI test would not be usefull. Clearly, an established sever fiber loss condition not seen with the eye would be identified with the tester even with carpet and subfloor in the path of the test signal. Like testing window operation, we will not promise to find a problem - just if the floor seems excessively soft, and we want our client to tell his/her friends about the quality of our inspection, I would sure like to pull out this instrument… During one of my inspections a condition of sever powder beetle damage was not detected and definitely I would have used this tester to clearly show the client there was a problem.
Of course, I would not expect it to be helpful if used on concrete - who knows though, maybe it could be.
Thanks Robert, and thank you for the words of encouragement. I will not, however, be part of an effort to sell a product that will not do what it is intended to do.
Also, would you mind posting your response on the “Poll …” post, I would like to get them all together. Thanks.
From that description of “floor system” I assumed you were talking about the flexibility of framing system or members. Calculations or load testing is needed to accurately evaluate that.
I am familiar with MSR lumber (and you also mentioned “reported stiffness values”), and the accepted method is to subject each piece to a known load and measure the response to that load in order to establish a “stiffness” (which is a resistance to bending, not a density), and thus the strength … see the attached tech bulletin from WWPA from http://www.wwpa.org](http://www.wwpa.org). My understanding is that some newer non-load based technologies are out there, but there are problems and not generally accepted or used by producers (but perhaps something has changed recently with grading rules).
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[/FONT][/size]Now that sounds like you are trying to identify localized deterioration of wood members, and not the flexibility of floor systems/members. That is completely different from identifying a flexible floor (more along the lines of “why” a floor is flexible, which is not necessary as part of a home inspection). I believe for something like that to work it would probably have to be placed directly on the piece of lumber in the suspect area (similar to pulse/impact testing for concrete) … in which case you might as well just get out the awl and probe the lumber.
If you are trying to identify localized deterioration of non-visible members from above that also sounds problematic and not practical. You wouldn’t know if you are directly over a member or not … and even if you were you wouldn’t know if there is say 2" of rot at the bottom of a 2x10 as compared to an undersized 2x8 member that is causing the flexibility.
Also, as an engineer any equipment or procedures utilized in field evaluations have a well established and documented/published industry research and laboratory testing, along with ASTM standards for the equipment and procedures. Otherwise I wouldn’t even consider using it. That’s why I recommended trying to contact someone at Lehigh University as they may be more helpful since you are trying to come up with something completely new.
Yes Robert, I do not disagree with most that you have said especially that “density” does not directly correlate to strength. This is why the X-ray technology used in the southeast of the USA is inappropriately placing “MSR” grades on lumber during production runs. I have seen comparisons where the X-ray assigned grade was very, very wrong - the boards were sold at a higher price than should have been and those making it to market probably used in structural applications where they should not have been used. I understand that this situation is being corrected.
I have directed the engineers working on the proposed tester to this thread - they too misunderstood my application need for the tester and found your comment helpful. Of course, the tester will be put to the scrutiny you have described above before bringing to market.
That said, I cannot agree that the application of such a tester would be questionable. Yes, I would not know if it was rot or an undersized member - I would not care because my purpose is simply to say “Have a structural engineer look at this…” And, if I make this statement without good cause and someone pays to have the area investigated AND I am wrong I will loose credibility. Hence, the tester would allow higher confidence in my recommendation and higher probability of a correct action. Another scenario, “am i over a joist or not?” Somewhere within sixteen or twenty four inches of the inside perimeter wall will be a joist and the tester reading will, I estimate, read a substantially different value over the joist. While somewhat of a “witch hunt” I would find it interesting (fun if you will) as well as helpful. However, maybe the tester is better suited to the “Contractor (re-modeler)” or Pest (WDO) inspector, or Engineers than to the Home Inspector. I believe the tester developer will not go too far on this if their preliminary analysis finds it a hopeless endeavor.
As hoped, your comments have helped communicate to the developer the considerations essential to the development of the tester, foremost being its simplistic intent. Thanks so much for your thoughts and time.
I will let you know if the project moves foreward.
