Reuben's Home Inspection Blog


Deck Inspections: Check The Guardrails

The CPSC estimates that between 2003 and 2007, there have been over eleven thousand injuries caused by structural failure or collapse of guardrails at outdoor decks.  It's not tough to understand why - when people have parties in the summer, everyone hangs out on the deck.  Throw in a keg of Busch Light, a few (ahem) 'people' that make the rockin' world go 'round, and a weak guardrail... boom.  Guardrail collapse.  Weak guardrails are one of the most common safety issues with decks.

The current requirement for new deck guardrails is that they withstand 200 lbs of pressure at any point along the top rail (Table R301.5).  Actually, this standard applies to all guardrails, both inside and outside the house, but decks are the place where it matters most.

My standard method for testing guardrails has always been to just push on them a little.  If they feel weak, I recommend having them reinforced or rebuilt.  Once a guardrail moves an inch or two without much pressure, I stop pushing; I don't want to be the one to break it.  Home inspections are supposed to be visual, I know, I know... but I like to touch stuff.

I've never used any type of testing equipment, but I recently picked up a fancy-schmancy piece of highly specialized deck guardrail testing equipment to help get a better idea of what 200 lbs of pressure felt like.  Jealous much?

Sunbeam Scale

Ok, it's just an $8 bathroom scale.  After some playing around, I've learned that 200 lbs is about the most pressure that I can personally apply to the top rail of a guardrail, just by standing on the ground.  In the photo below I'm applying about 150 lbs of pressure, and I'm straining to do it.

150 pounds of pressure

The weakest point in most guardrails is always going to be at the end, where it terminates next to the house.  All that typically supports the guardrail at this location is the 4x4 post, assuming posts were used to construct the guardrails.   In the photo above, I'm pushing on the guardrail at the end.   This guardrail actually performed fairly well - most guardrails won't tolerate nearly that much pressure.

The surest way to construct a guardrail that will withstand 200 lbs pounds of pressure is to use metal brackets that are designed just for this purpose.   A couple manufacturers that make such brackets are DeckLok and Simpson Strong-Tie.   If special metal brackets aren't going to be used, the support posts should be constructed with full size 4x4s (not notched at the bottom), attached with through-bolts, and extra blocking usually needs to be installed to help keep the guardrail secure.

In the photo below, the ovals show where extra blocking was added.  This blocking tremendously stiffens the joist that the guardrail is attached to, making it so the guardrail won't budge even when a full 200 lbs of pressure is applied.

Nice Guardrail

The bottom line is that weak guardrails are a safety hazard that should be corrected, especially on decks that are high above the ground.  For specific guardrail construction methods and rules, turn to page 15 of the  Prescriptive Residential Wood Deck Construction Guide.

May is Deck Safety Month - Related Post:

How to prevent your deck from collapsing: start by attaching it properly


Reuben Saltzman, Structure Tech Home Inspections


Comment balloon 18 commentsReuben Saltzman • May 15 2012 03:38AM


Thanks for the information. Homeowners should check the guard rails regularly as it is for their own safety as well.

Posted by Gita Bantwal, REALTOR,ABR,CRS,SRES,GRI - Bucks County & Philadel (RE/MAX Centre Realtors) almost 8 years ago

Gita - that's what it's all about.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 8 years ago

Reuben, i am bookmarking this article for clients...i had one guardrail last year that had an issue and was up about 20 feet and scared was reinforced well but this test is a winner..thanks!

Posted by Ginny Gorman, Homes for Sale in Southern RI and beyond (RI Real Estate Services ~ 401-529-7849~ RI Waterfront Real Estate) almost 8 years ago

Hello Rueben,

Nice way to check out the "strength test of a hand rail".

Let's hope it do'es not give way when applying the pressure to the railing. You might go "bump in the day". LOL

Thanks for the tip.

Best, Clint McKie

Posted by Clint Mckie, Desert Sun Home, Comm. Inspection 1-575-706-5586 (Desert Sun Home, commercial Inspections) almost 8 years ago

Good info bub!  I had a "guardrail" the other day which was a 1" by metal "post" at one end of the deck, with another about 10' away and another at the corner.  Total about 20'.  There was a single bar along the top, tack welded to each post.  Viola!  Guardrail!  Oh, it was 30" high!

Wow, looking at that photo above I am surprised that punk could push, um, really impressed that the guardrail stood up to that guy!

You don't need that scale you know.  Let the Force be with you - feeeeeel it Reuuuuubs, feeeeeel the Force flow through yoooouuuu....

OK, I suggested it.  I do almost all inspectors' posts, so don't get a big(ger) head.    ;>)

Agape smooch fellow brother.

Remember the Force.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) almost 8 years ago

I am jealous. That fancy guard rail tester is awesome! 

I have to say, I have or at least can't recall seeing blocking like you show in that photo. I will be looking more closely. 

Posted by James Quarello, Connecticut Home Inspector (JRV Home Inspection Services, LLC) almost 8 years ago

Reuben, I gotta head down to the good-will and get me one of those fancy testers :)  I am starting to hate decks more and more.

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) almost 8 years ago

Thanks for the post! Just had a guardrail that needed repair on a listing. Don't want the false sense of security over-riding causing any accidents. 

Posted by Gina Tufano, Ask Gina & Company, Northern Virginia Real Estate (Ask Gina & Company with Pearson Smith Realty) almost 8 years ago

Another great post Reuben.  I have noticed issues with railings, both inside and out of late.  I will re-blog this post for the benefit of my audience.

Posted by Chris Smith, South Simcoe, Caledon, King, Orangeville Real Esta (Re/Max Chay Realty Inc., Brokerage) almost 8 years ago

This is a rare topic but a very important one.  Many don't realize that appraisers, especially FHA and VA,  are very aware of the safety of staircase railings!

Posted by Sidney Kutchuk - Realty Works Temecula Kutchuk - Realty Works Temecula, Realty Works Temecula (Realty Works Temecula) almost 8 years ago

I hate to say it, but deck guardrails are probably something that is often overlooked on an inspection.  When husby has the boys over for beers, there can be a lot of weight leaning on those rails... and as far as I know, most husbys don't bounce well when they fall off decks.

Posted by Karen Anne Stone, Fort Worth Real Estate (New Home Hunters of Fort Worth and Tarrant County) almost 8 years ago

Reuben, Funny you did a vid on that. I have several vids now of guardrails that I can push around pretty easily. I have a few real nice ones showing lags being lifted right out of the decking.

Like others here I love the test tool. 

I tell you we should have a challenge to see if we can find a deck done completely correctly.

Posted by Donald Hester, NCW Home Inspections, LLC (NCW Home Inspections, LLC) almost 8 years ago

Ginny - If you try this test, just be sure not to push too hard :)

Clint - no doubt!  It hasn't happened yet...

Jay - that sounds pretty scary!  Given a running start, I'm pretty sure this guy could take out most guardrails with a good shoulder check ;).  

I'll try using the force next time.  I'll try to get a video of me doing it.  If I do, I'll send you a link.

James - right?  The problem is, you can't just get these anywhere.  They don't sell these things at restaurants, doctors offices, or banks.  You have to go to a retail store to find one of these.  I was pretty surprised to see that blocking myself.  Nice detail though, huh?  

Charles - me too.  Decks usually involve a lot of writing.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 8 years ago

Gina - guardrails are no joke.  

Chris - thanks, much appreciated!

Jane - I certainly wasn't aware this was a thing with appraisers.  I was under the impression that the repair requirements for handrails on FHA appraisals had gone away.  Are you saying it's back again?

Karen - that's exactly what I'm talking about.  I know of one inspector who likes to tell his clients to ask themselves: "Who is your largest friend?  Do they drink?"

Donald - where are said videos?  I looked up your YouTube channel, but could only find seven videos, and none of them seemed to be about guardrails. 

Talk to James about the perfect deck.  He claims to have inspected it about a week or two ago :)

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 8 years ago

Donald - never mind, I see you didn't say anything about posting the videos to YouTube.  

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 8 years ago

Great post and so true. I had a good friend who was leaning on his own deck rail when it broke. The deck was about 20 feet off the ground. My friend died from his fall.

Posted by Tom Bailey (Margaret Rudd & Associates Inc.) almost 8 years ago

I don't care how much you strengthen a guard rail.  I don't think that a single rail is anywhere near enough.  What happened to Tom's friend in #16 happens much too often. 

The entire side of the deck needs to be constructed in such a way as to make it take much more punishment and pressure than one huge man leaning against it.  I am thinking it should at least be like your bottom picture, above.

Posted by Karen Anne Stone, Fort Worth Real Estate (New Home Hunters of Fort Worth and Tarrant County) almost 8 years ago

Tom - woah.  I'm sorry to hear about you friend.  Thanks for sharing.    

Karen - that's about what I'm recommending.  As decks get older and hardware gets loose, they lose strength. 

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 8 years ago