Notching Or Cutting Holes In Engineered Floor Joists
Code, Shmode.
It doesn't take a Rhodes Scholar to know that when a critical support for anything, anywhere, anytime is 
breached, the strength of that support has been reduced. That's not construction, that's simple physics.
TEST OF TIME. If I outlast some of the manufactured building materials used by the industry today, I won't be surprised. For instance, I will admit that I am not an admirer of OSB. I don't care what the builder says. I've stood on it and felt it BOUNCE under my feet. If nothing else, what does that do for the carpet backing??? Now the industry is building entire home of "manufactured materials". Fine. Let me say on thing. THESE MATERIALS HAVE NOT STOOD THE TEST OF TIME.
WHO ARE YOU GOING TO BELIEVE, THE MANUFACTURER'S CLAIMS OR YOUR LYING EYES! I've witnessed homes with damp basements whereby the OSB sub-flooring has swollen to a point where it buckles, shakes, rattles and rolls, all in difiance of the manufacturer's claims to the contrary.
For some years, my new home buyers would spend an extra $1,000-$1,500 to upgrade subflooring from OSB to plywood. For the past 5 years or so, builders wouldn't even consider that upgrade. Of course, the thickness of the materials is important, but still, those 100-150 year old homes with PLANK subflooring are as sound today as they were when constructed. Not so with homes built in the past 25 years with more and more manufactured materials.
STRESS TESTED? What does industry testing say when the airplane survives the wind tunnel test, but in flight, the tail assemply falls off??? HA!
What I have learned over the years from smart home inspectors is, sure, the manufactured building materials are strong, if not tampered with.
I've also learned that when SUPPORT BEAMS have huge holes punched or cut into them to accomodate hoses, wiring, etc., that BEAM has lost the ability to do what it was designed and installed to do, bear the weight of a HOUSE.
I've also learned that, when a builder's construction supervisor cites to the code, they are endorsing a "bare minimum" standard for construction. I CAN NAME NAMES. This is, BTW, all price sensitive. There are levels of quality construction in new homes that, with experience, agents and home inspectors learn. For home buyers, don't expect a silk purse from a sow's ear.
Courtesy, Lenn Harley, Broker, Homefinders.com, 800-711-7988.
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A popular construction material these days are floor I-beams, sometimes called "Engineered Floor Joists." You have seen them. They are convenient and easy to use. But there are strict guidelines for notching or cutting holes in engineered floor joists.
From the side they look like a steel I-beam. There is a top and bottom section, with a vertical member in between. They utilize a lot of glue, which is why the fire department does not like them if they get too hot. The glue melts!
There are strict guidelines for their installation, necessarily. They are strong when left intact, and not so strong if cut
improperly. Hence the guidelines.
These guidelines are based on codes imposed by Mother Nature. She is a very strict disciplinarian.
But she also enforces her codes with impunity.
Just look at her! Impunity I tell you! Impunity means "exemption from punishment or consequences." Go ahead, try to punish Mother Nature for her code enforcement!
These guidelines have been developed by engineers after much testing and analysis. The local building codes are based on these criteria.
IT DOESN'T MATTER WHAT THE CODE SAYS IF YOU VIOLATE MOTHER NATURE! SHE CAN BE MERCILESS.
This diagram shows those guidelines.
The Moment Critical Zone is the only area that notches or holes should be cut.
If holes are cut at the edges, you see, the beams can shear off!
If cut at the bottoms and on the sides, you remove the beam's ability to bear weight.
But all three pieces, working together, are very, very strong.
The physics works. That pleases Mother Nature.
This photo shows cuts made in consecutive beams to accommodate a metal HVAC duct.
The cut holes are dead center in the beams.
They are fine!
Both Mother Nature and the local codes are pleased.
But what happens when the local code is met, but Mother Nature might not like it?
On this new construction the builder's answer to my pre-drywall inspection comment was, "It meets code. We are only required to make changes when we are not code compliant."
In this case I am not so sure!
This is the next joist beside a load-bearing wall. This stud wall is directly under another load-bearing wall above. It is the wall between the kitchen and dining room.
This I-beam will be holding a long granite counter top and cabinets. That hole on the left was cut in the wrong spot and they simply moved over and cut another one. Yes, the hole is within the "zone" for such cuts. But a large section of the center of this beam has been removed! Do you think that affects its strength?
You can see also plumbing pipes along the top and a gas line on the bottom. What if Mother Nature impugns this arrangement? It's to the local code! Is it to her code?
Dead load is the weight of the materials introduced and put into a house. In this case it would be granite and kitchen cabinets and ceramic tile flooring.
How much "live load" (that's the load that will be introduced after the dead load like from kitchen stuff) will be put in those cabinets by the occupants of this house? My answer -- "dunno."
How much live load will Mother Nature allow before cracking this beam? My answer -- "dunno."
When I suggested all this to the builder, the answer was NOT surprising. "Dunno."
Did they shore up that I-beam before the drywall was installed? NO. Why? "It meets code."
Alrighty then!
My recommendation: people are not smarter than Mother Nature. Physics works unless a countervailing force overcomes it. But even though we have learned to control gravity, somewhat, gravity is STILL in control. And I remain concerned about the gravity of this installation.
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia
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