How to Perform Deck Inspections - Guardrails

The training documentation says

Decks that are greater than 12 inches above adjacent areas should have guardrails
around the edges. Some codes require guardrails only around the edges of decks 30
inches or higher.

This feels ambiguous. Other trainings have stated 30 inches + need guardrails. Now I come across this. Is it 12 or 30 - there’s a big difference here. Or is it reaching out to AHJ - which feels troublesome depending on the number of AHJ’s within your scope. Or another “it depends”? Because if “it depends”, the material doesn’t yet draw out the dependencies.


Tom Baty

It is 30. The author of the training documentation may have been expressing personal opinion when using the word “should.”

1 Like

As Ryan said the code is 30" but age presents another need. My father lived to 98 but as he got older the front porch of his home which was barely 20 inches off the ground got guardrails to help him get out of the chair on the porch and navigate to the front door. The front steps also got handrails for those times when he had to go to the doctors. Safety needs change as we get older. Uneven walking surfaces that we easily stepped over in our youth become trip hazards later in life. Water temperatures that we could stand when younger scald when we are older.


This is a unique “recommendation”. The author demonstrates the difference between a home inspectors opinion and a code requirement.

Our opinion matters.

A typical narrative may go like this; Though not required by code, I recommend a guard rail (here) for additional safety.


Good feedback - thank you!

Brian - I’m looking at things more ‘safety’ oriented than code. However, I also am concerned about putting out too much opinion about what’s safe and what’s not. This could lead to a bad rep about being overly cautious and lead to spurious results with sales. Not that we’re focused on good sales outcomes, but it matters. Don’t want to be known as the deal killer!

Bob -

Good point - one I hadn’t put in my head yet. Very valid. And perhaps is a targeted point to be used with the proper client. Thanks!

Our number one job is to put our customer into a safe house.

Forget that thought. Your loyalty is with your customer only. If you think your customer may be injured by a building component, call it out.

Also worth noting on this topic, if there is a guardrail installed even when not required, it should meet the standards for a safe guardrail (height, spacing, strength, etc.).


All excellent points posted above. Keep in mind as well that local jurisdictions can adopt their own changes to codes. They may even define a deck differently than say an elevated porch or patio. An example is a city just North of me has railing requirements for porches and patios at or higher than 30" but only 24" for decks in their municipal code.

Regardless, the safety of your client is what is most important.


I have asked this question on other forums (years ago). This is the most definitive answer I have ever seen! Can I quote this?

Go for it! And it makes sense. Even if a guardrail is not required, if one exists it should be a safe guardrail. It is mentioned a few times in the Nachi CPI training.