«  View All Posts

Is Your Deck Putting You In Danger?

July 28th, 2023 | 5 min. read

By Phil Parsons

Is Your Deck Putting You In Danger?

Is your deck dangerous? 

Odds are good that if you’re reading this, you’ve noticed a crack in a deck post, some rot in the boards, or a loose railing. You want to know how to fix these problems so your deck doesn’t become a source of danger for your family and friends. Fortunately, the nice thing about safety is that even little fixes compound quickly (hence the old imbalance of an ounce of prevention and a pound of cure). If Murphy's Law always holds up in court, safety precautions are your escape clause from disaster.

Homeowners like you know this all too well. What you may not know, though, are the specific warning signs of danger. Odds are also good that you didn’t build your house, so there could be structural weaknesses you’ve never thought to check for. This goes for your deck, too.

At KP Contracting, we’re experts in helping people make their outdoor living dreams into realities. But safety is the necessary prerequisite for enriching any part of your life. In this post, we’ll review the five key signs your deck might be a source of danger. We’ll also give you an idea of what steps you should take if you answer “yes” to any of these questions.

Top 5 signs of danger

> Is your ledger in good shape?

> Is your hardware in good shape?

> Is your deck’s material in good shape?

> Are your railings in good shape?

> Are your posts and beams in good shape?

Is your ledger in good shape?

Your deck might be putting you in danger if the ledger is improperly connected, or has extensive cracks. 

The ledger is the beam that connects the deck to the house. It can also be a source of trouble if improperly connected. According to the Virginia Tech professor Frank Woeste, poorly connected ledgers are a main cause of deck failures. Specifically, the problem is ledgers connected by nails, rather than lag bolts or screws. 90% of deck collapses are the result of nailed ledgers. Nails aren’t able to withstand use pressures as well as lag bolts. In some cases, a ledger that’s been nailed in can pull out of the house, and tip over, taking with it whoever is unlucky enough to be on it at the time. And as for that “whoever,” as few as two people are enough to pull a nailed deck out of the side of the house.

An image from a 2023 deck collapse in Clinton, Maryland

A cracked ledger is also a source of possible danger. Check for cracks in the ledger. If more than ⅓ to ½ of the ledger is cracked, it’s a good chance you’ll need it replaced. A crack of that size in the ledger board makes the deck less likely to stay connected to your house, or bear whatever load you put on it.

A lack of flashing can also make trouble for your ledger. Flashing is the shingle that prevents water or other elements from seeping into the space between house and deck. Without flashing, moisture can seep into the space between deck and house, corroding the ledger, and possibly spreading to the beams as well.

A lack of flashing can lead to corrosion that undermines the structural integrity, like this.

Are your posts and beams in good shape?

Wood decays over time, especially in moist and humid climates like southern Maryland. How humid is the D.C.-Baltimore region? In the 1960s, the British Embassy would pay their employees the same extra wages they paid employees in the Tropics to tolerate the soupy air. This humidity puts strain on wood, too. If your deck’s wood is rotting, then your deck can become a danger to you and your family. 

To tell if your wood is rotting, poke the area in question with a screwdriver. If the screwdriver goes into wood that feels spongy, that’s a sign of rot. Another method to check for wood rot is the pick test. To perform the pick test, stick an icepick or screwdriver into the wood, and pry a piece up, in the same direction as the grain. If the wood splinters easily, and makes a cracking sound, it’s dry and in good condition. If the wood is silent and produces no splinters, it’s probably rotting. 

A depiction of the pick test, from the International Association of Certified Home Inspectors 

At 0:25 of this video, there’s a demonstration of a test for wood rot:

How to tell if the wood on your deck is bad: 2 Wants to Know

Extensive rot can cause deck collapse. If even a single post is rotting, that can take the rest of the deck with it. 

Also check for leaning and sagging in your posts and beams. The beams that support the deck’s floor should be straight and even. If the beams underneath your deck are curving, that’s a sign those beams need to be replaced. 

If your beams are curved like this, they’re sagging. Enough of these can lead to a collapse.

Is your hardware in good shape?

In this case, hardware means the screws and nails that keep your deck together. If enough of your hardware is rusting, it won’t be able to support the load. Rust is especially a problem in wet/humid climates like southern Maryland and the Eastern Shore (and, side note, the International Residential Code requires your fasteners be made of stainless steel if your deck juts into the ocean, or is within 300 feet of salt water). 

If you can wipe the rust off the head of a screw or nail, the nails or screws are probably ok. If, however, you can’t wipe the rust off, that may be a sign of deeper damage to the screw or fastener. 

Are your railings in good shape?

If a four inch ball can pass through your deck’s railings, they’re a danger to children. Four inches or more is enough space for a small child’s head to get stuck. If your railings are too far apart, it will be necessary to install new ones that make the deck safe for kids.

If your railings shake, or nails and screws are rusted or coming undone, that’s a further sign of possible danger. Someone putting weight on a rickety railing can fall through. Weak railings can be a legal danger, as well. A 2017 case saw over $1 million in restitution demanded from a landlord when a woman fell through a poorly-made deck railing. 

Is your deck’s material in good shape?

Make sure there are no signs of splitting in your deck. Enough splits in your lumber can undermine the stability of a deck, particularly in posts, joists, or the ledger. Lumber with extensive splits should be replaced.


If you’re in the planning stage, make sure to pick a material that will last longer. This means pressure treated lumber in the case of wood, or a composite material like Trex or Fiberon. It also means looking for water-resistant woods like Western Red Cedar, African Teak, Oak, Tigerwood (Ipe), and Cherry. 

The most important question about deck danger

Want to reduce the above five questions to one? Ask yourself this: Am I doing regular inspections of my deck? If the answer is yes, you’ll ask these five questions less frequently, and like the answers better. 

You should inspect these deck features at least once a year, and after major storms and weather events like hurricanes, electrical storms, or the rare Maryland tornado (although, one of the two biggest Maryland tornadoes since 1950 passed through Charles County).

And if you want to go into more depth than these five questions, download our Easy Guide to Deck Inspection. 

5 Questions to Generate Deck Ideas

If you answered “no” to any of the above questions, your deck might be in need of repair, or even replacement. You know when a crack or rot is worth the worry, and whether the bars in your railing are a safe distance apart. Now’s the time for action, but that action depends on your priorities. 

To find the best choice for either repair or replacement, ask what your priorities are:

> Am I looking to sell my house in the near future?

> How old is my deck? 

> What sort of outdoor living do I want to get out of my deck?

> Is my deck big enough for my family, or any future additions?

> Am I thinking of making any other major renovations or additions to my backyard which would affect my deck?

All of these questions will help inform whatever next steps you want to take with your deck, or other outdoor spaces. If you’re interested in an inspection by a professional, reach out to us at 240-266-5900, or get in touch with us online here.

Phil Parsons

Phil Parsons is an owner at KP Contracting with 20-years’ experience in custom remodeling and the development of outdoor living spaces that bring friends and family together. He is a degreed engineer, and his work has been featured on HGTV.