This is a serious problem that is prevalent because of amateur or un-informed workmanship. The only railing systems that can be attached onto the deck surface are solid metal types designed to be surface mounted. All wood systems have to pass through the decking and be through bolted into the framing.
This article is written by an experienced Virginia inspector. His tone is a bit sarcastic but he illustrates the point very well.
Toe nailing is a valid carpentry technique. But for the most part it is a temporary tacking of one thing to another by nailing two things together at an angle. Then proper attachment can be made. Toe nailing is seldom, if ever, intended for long-term attachment or support with heavy material.
Walking around this deck, only about 4′ high, I noticed that every single guardrail post had been toe nailed to the decking!
Don’t trim those toe nails!
You can see how substantially attached that post is to the deck (he sarcastically notes). Many wobbled a lot! Rock on dude…
Despite the VERY FINE paint job, this is a huge problem.
Sure, the deck is only 4′ high. Do you want to fall 4′, land on top of a broken guardrail, and land at an angle you can’t control?
Didn’t think so…
Where do people end up when they go out onto a deck?
The guardrail! They lean. They put weight. They ASSUME it’s safe.
The code would like the guardrail to easily support about 200 pounds. That is all well and good. But often more than one person is leaning against the rail! Remember, the code is a MINIMUM STANDARD! And a well-attached, or properly-attached, post can support far more than 200 pounds. How should deck posts be attached?
There are various ways.
They can be attached on the outside of a joist, or the inside. Two can be attached surrounding a corner.
BUT ALL MUST BE ATTACHED WITH TWO THROUGH BOLTS THAT ARE SEPARATED FROM THE WOOD WITH LARGE WASHERS.
The bolts, washers and nuts should be of the same material that resists corrosion (stainless steel, galvanized or zinc dipped). The most common would be galvanized.
Carriage bolts are not good bolts to use!
The round head is not wide enough and when the nut is tightened the round head actually gets sucked into the wood. And the square end under the round head does not accept a washer. Carriage bolt use was emphasized by the engineers at my recent Strong-Tie seminar. Carriage bolts should not be used for post or beam attachment.
There are other criteria regarding guardrails that are important, but not the point here.
Proper attachment affords strength and safety. Safety is always the bottom line.
My recommendation: when you see a deck, have a look! Feel its strength as you walk on it or carefully lean on the guardrail. Check attachments. How does it make you feel? And get an inspector to have a look see should you put a contract on the house! Decks COMMONLY have problems. You want to know what they are!
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia
Original blog post on ActiveRain: Link to Blog Post