What I'm Seeing Now


Notching Or Cutting Holes In Engineered Floor Joists

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.


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.

Office (703) 330-6388   Cell (703) 585-7560


Comment balloon 27 commentsJay Markanich • August 26 2011 06:44AM


With all the new products and techniques in building it is very important to read the installation directions and how certain materials and products work with others. Plan a head please, this is one of the first rules they teach you in sustainable green building.

Posted by David Popoff, Realtor®,SRS, Green ~ Fairfield County, Ct (DMK Real Estate ) over 9 years ago

These I-beams have been out a long time David.  The builders all understand how to install them.  They may be playing with a little fire here though.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 9 years ago

Code, Shmode.

Is there a code for the huge and heavy antique Chinese cabinet/TV house in my family room?  Or the yards of Granite Counter Tops in my kitchen???



Posted by Lenn Harley, Real Estate Broker - Virginia & Maryland (Lenn Harley, Homefinders.com, MD & VA Homes and Real Estate) over 9 years ago

Good morning, Jay....engineered wood is a fantastic material and saves the builder all of the recall trips when the moisture content in dimensional lumber shrinks and the plaster cracks, doors and windows shift, etc....today, engineered wood comes with predrilled holes for pipes and wires....every 2' O.C.....there are knock outs......

Posted by Barbara Todaro, Previously Affiliated with The Todaro Team (RE/MAX Executive Realty - Retired ) over 9 years ago

That's interesting Lenn that you say this.  People often create home offices in bedrooms and the "code" was never written to accept all that new live load.  Hence problems develop.  Codes are usually in response to, and not in anticipation of, what is going on.

Barbara - all true!  And those are very small by comparison to HVAC cuts.  Too much cut, too little support!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 9 years ago

Maybe the codes need more revssion, too (esp w/ all the granite being used now).

Posted by Debbie Gartner, The Flooring Girl & Blog Stylist -Dynamo Marketers (The Flooring Girl) over 9 years ago

Notching and cutting or engineered materials must be done according to the manufacturers specifications.  Same goes for a broken or modified engineered roofing truss. "When in doubt, get the manufacturer's rep out" ...and have their engineer provide a signed and sealed document indicating the installation is structurally sound.  Make three copies, one for your file, one for the homeowner and one to staple onto the repaired area.

Posted by Daniel H. Fisher, MCRP - Charlotte Real Estate, NC or SC (www.FisherHermanRealty.com (704) 617-3544) over 9 years ago

Jay, Notching any joist or support beam can have consequences, but engineered joists are should never be notched according to a course I took last fall. Great Post!

Posted by Chris Smith, South Simcoe, Caledon, King, Orangeville Real Esta (Re/Max Chay Realty Inc., Brokerage) over 9 years ago

All the materials they use now can handle granite loads Debbie, IF they are spaced properly (meaning closer together) and notched properly.  The supervisor on site is supposed to know that.  Key word - "supposed."

For sure Daniel.  But the builders already know all these things.  Calling the rep would be fine, but he will just say space it like this, notch it like that.  He would think coming out is busy work.

Chris - the diagram expresses the industry standard for notching.  If varied from, problems have to result!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 9 years ago

Jay, of course all manufacturers are different but my "Silent Floor" TJI book, even on a TJI/55 x 16, says the maximum hole size is 12-3/4" square---appropriately located of course.  All that ductwork sure looks bigger than that.  What am I missing?

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) over 9 years ago

Jay - Having used "Silent Floor" joists for several years, I'm well aware of their advantages and limitations. Unfortunately, unless you are standing there guiding the subcontractor--my strategy--you often wind up with improper cuts.

Posted by John Mulkey, Housing Guru (TheHousingGuru.com) over 9 years ago

Jay -- what a great picture of "mother nature".  Of course, you had other options, like Hurrican Irene, or the tsunami. But this one gets the point across well.  Have a great weekend!

Posted by Steven Cook (No Longer Processing Mortgages.) over 9 years ago

Without looking at any specs that hole looks bigger than I can ever recall being allowed by any manufacturer. And code don't mean jack when it comes to manufactures specs. Builders, gotta love how they wrap themselves in their protective code blanket.

Posted by James Quarello, Connecticut Home Inspector (JRV Home Inspection Services, LLC) over 9 years ago

Hi Shadow!  That trunk is 12x12".  You can kind of tell by the dryer vent used as an HVAC duct!  It's dead center too.  They cut that hole nearly exactly to the size of the trunk.  But not that big one beside!

John - in my opinion, why would you need to stand beside professionals to supervise something as simple as that?  Oh, my mistake - 7-11 construction!

Steven - I was going to use this one!  But she seems a bit too stern for a Mother Nature with enough schtick to impugn as she enforces!  She also looks like my second grade teacher!  I was home sick a lot...

Jim - I hate that.  I like to say, "So, you build your houses to a minimum standard?"  That always gets them.  I should sick Mother Nature on them.

I agree about the code.  When things are "engineered" that means that someone has his/her own specs!  If that isn't enough, there is always gravity.


Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 9 years ago

Hi Jay...really great info...it's so scary to not know if the ibeams holding your house up are truely supportive or not..In your opinion what is the best type of beam to be looking for? Steel..wood..?

Thanks, Tara

Posted by Tara Stone, NJ Estates and Stables (eXp Realty) over 9 years ago

Tara - wood I-beams are fine when installed properly.  In the center of the house, in the basement, often it takes a steel beam to carry the load.  I have three steel beams in my house!  And bunches of floor I-beams!

Tell David he should open his Realty Group in Virginia!  You wanted me to open an office in NJ, but I couldn't afford the taxes!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 9 years ago

More often than not manufactures specs supersede code. I bet Mr. Builder doesn't like to hear that either.

Posted by James Quarello, Connecticut Home Inspector (JRV Home Inspection Services, LLC) over 9 years ago

Necessarily Jim, if the code is the minimum standard.  Does the engineer designing a product want it used in its lesser-capacity or least-ability circumstance?  But that is exactly what the builder does!  And is still "obeying the law."

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 9 years ago

Jay, thankf for being an excellent inspector, a terrific writer and someone with a good sense of humor!  I thought maybe that was your mom--same hair--ha!!

Found you on Lenn's re-blog.

Posted by Gayle Rich-Boxman Fishhawk Lake Real Estate, "Your Local Expert!" 503-755-2905 (John L Scott Market Center) over 9 years ago

Well that's the way it always works.  Once the city/town building inspector completes their inspection report, the builder will not make any changes.

How did your buyer handle all the information?

I wonder if this house will end up in a law suit.  There was a recent law suit in MA, a beautiful house on Lovers Lane.  The newspaper story title reads "Family imprisoned in a home of horrors".  You can imagine how bad it got.  Part of the story reads "after a monthlong trial in Middlesex Superior Court in which they sued their contractor, broker, and seven others, the presiding judge made the rare decision... "


Posted by Jim Mushinsky (Centsable Inspection) over 9 years ago

Thanks Gayle.  I try to be instructive and have a little fun at the same time.  But it's true - go against Mother Nature!  No, not my mother.  She retained the same hairdo she had in the 50s for the rest of her life.  And gone for many decades now.

Jim - this was not the only thing to concern her.  We will have to see what the live load brings to the circumstance! 

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 9 years ago

Don't let all that gravity get you down Jay, after all you don't have to live there. Isn't that what the builders crews says?

Nice of you to put in that picture of your Mom though.:))

Posted by Robert Butler, Montreal Home Inspector | Aspect Inspection (Aspect Inspection) over 9 years ago

Robert - what they forget to say is someone has to live there!  And that lady looks like a lot of fun, though not my mother!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 9 years ago

I'd be curious to hear what the manufacturer had to say about those holes.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 9 years ago

I typically don't contact manufacturers after home inspections Reubs! Do you?

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 9 years ago

I, regularly, see things that are "code", but are just plain wrong.  Some times the codes are old and have not been revised, somtimes the product is new and the code has not caught up with it yet.  In all cases, the manufacturer's installation instructions will override local codes.

BUT....  To often, builders only see the local code requirements as their only requirement.  No attention to detail or continuing education.

In any case, all this boiles down to liability.  "Who will pay if someting goes wrong, and especially if someone gets hurt?"  That is the real bottom line.

I make sure, by my inspection and my report, that the person holding the liability is not me.  I write my report in such a way that I help my client to also not have the liability.  If the builder says that it is OK, then the builder holds the liability.  Unfortunately, many times the local municipality has liability immunity.  This is true everywhere in Illinois.

I had a new construction house, a couple of years ago, that used OSB I joists, like these.  The builder had the first floor partially built when it started to rain and these joists got wet.  The manufacturer's installation instructions state that they cannot get wet and I told the builder that (and even showed him the manufacturer's documentation) be he said it was OK.  I talked to the local code inspector, when he came by, as he also said they did not have to be replaced.  I wrote it into the report for my client, but the builder and the builder's agent told the client not to worry and that I was just "being too picky".  The client closed on the house.

9 moths later, I recieved a call from the client.  Seems that the floor under the kitchen had "sunk" (actually, partially collapsed).  I checked it out and found that the OSB webbing had delaminated and partially rotted (finished basement, so we had to open the ceiling).  No signs of any water damage source.  The joists had goten wet during initial construction.\

Long story short, the client sued everyone.  I got off because I had called it out.  The builder had to pay a small amount but relied on the contract which only required him to build to the local code standard.  The Village declared immunity.  The client's insurance disclaimed it because they said it was a "construction error".

So, the client ate the major costs.

DO NOT rely on local codes to protect you.

Hope this helps;

Posted by William Decker (Decker Home Services, LLC) over 6 years ago

Agreed Bill!  I often refer instead to Best Practices.  In fact, I started a Best Practices group here on AR.  Check it out!

(My post today about the attic access ladder was proclaimed by the county to meet code... ummm...)

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 6 years ago

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