Deck Safety and Building Science

A lot of homeowners enjoy entertaining family and friends, most of which maybe on a patio, the beach for those with waterfront properties and of course our decks. Let’s stop and think for a minute about those decks. Let’s think about the safety aspect and how your decks are built. Would it shock you to know that a high percentage of decks built today are not built right? 40 million decks in the United States are over 20 years old, so it's crucial for homeowners to check their decks. Many were built before code requirements were in place to protect consumers. Some of these decks may have deck-to-house attachments using only nails. Others have become weakened through the years, and the owners don't realize how close to collapse they may be.

Permits – it’s not a bad word people… they’re there to protect you, and not just the liability side (when you hire a professional, because they should be applying for the permit not you). Building codes, whether it’s minimum (not good enough in my world), or a licensed contractor who is a craftsman and cares about his/her work going beyond the minimum; permits have the safety side as well. Looking beyond the regulations and actually taking the time to understand WHY you have to use all the provided nailing points in a joist hanger (with the right fasteners) is critical for the consumer’s safety and a long lasting structure.

Technical Data (yes there is mathematics involved, and NO, COMMON CORE math will not work here) 
– Simpson Strong-Tie, one of the leaders in construction connectors has detailed tables of data so that professionals and the DIY homeowner can properly select the right connectors for a safe structure.

So let’s take a typical 2’ X 10” piece of lumber (floor joist on a deck structure). Using a Simpson LUS210 hanger and the correct 10d common nails (@ 3” in length) (12 connection points per hanger), it has a weight load capacity of over 1,300lbs. That’s a lot of weight right? OK, let’s flip this equation around to evaluate of how it’s done the wrong way (in most cases this is true). Using the same hanger with only 1 ½” 10d nails the load capacity drops to 825 lbs. Going one step further and reducing the amount of nails used in each hanger (yes this happens more often than you think – cheaper is better, RIGHT?) down to 8 connection points (3 in the header and 1 in the joist – per side)… This is still more than half the nails used but now the load is reduced even more to 619 lbs. (less than half the original capacity). Think about it…

The Extra Mile – My two cents in this matter is always “go above and beyond”. You get what you pay for in the end. Cheaper is not better… PERIOD!!! If you hire a professional, make sure they can provide structural plans (architect or engineer), be a part of the permitting process (meet the building inspector face to face) so you can learn the way it’s done the right way. Get a detailed contract with what materials are being used (all of them). If you feel it’s not enough, READ, READ, and READ some more… The information is available at your fingertips (online and your local book store). Also if you think doing it yourself will save time and money, YOU HAD BETTER THINK AGAIN!!! Don't be foolish, for in the end, you and your family's safety may be at the mercy of that poorly built deck.

If some of the information is too overwhelming, call in an independent inspector to consult.

Is there a rhyme or reason this one is 100% wrong? In 3, 2, 1 - Whiskey Tango Foxtrot