The use of the correct fasteners is critical and all too often overlooked.
Most everyone knows what a joist hanger is. It’s that simple little galvanized device used to hold up the end of a floor joist. Can be used indoors or outdoors, usually found on the common deck. Once all the deck / floor boards are installed, inspecting these little things can be challenging.
Crawling in under whatever is built can prove interesting.
Replacing the nails in those joist hangers with the correct fasteners will be even more challenging.
Joist hangers must be installed with very specific nails. It is NOT okay to just use short screws or any old nail.
This is one of the most common problems found during site inspection, the use of sheet rock screws instead of the approved, much heavier and stronger joist hanger nail.
Also ever notice all the holes in the joist hanger? Everyone hole should have the correct nail.
There are a number of basic things that must be done when building decks.
Each is very important and if not done correctly may lead to premature failure, even collapse.
Certainly the size of the lumber, span, size of the beams, support post size, footings, handrails and post are all important.
All too often what is overlooked is how all these various parts are connected to each other.
Take a look at your deck. If all you see are nails, no nuts & bolts, fasteners, flashing, hex head screws, joist hangers, post connectors or any other indication of something other than just nails, you really should have a professional take a good look.
Are the posts down to proper frost depth? Are they sized properly? Is the rim joist properly attached to the building with the use of galvanized lag bolts, through bolts or ledger lock screws? Is there flashing behind the rim joist? Was the flashing properly installed above the floor of the deck? How are the beams connected?
Do they rest on top of the post or are they just “nailed” to the side of the posts?
There have been failures of decks or other elevated platforms which would have been prevented if things were done correctly.
Not long ago a large deck separated from a house and collapsed during the winter months.
The rim joist (that board attached to the house) was just nailed… it looked like a porcupine.
Someone had a lot of fun with their air nailer gun. Hundreds of nails… it pulled away from the house.
Depending on where the deck is located will depend on how much weight it may be subjected to.
Minimally it must be designed at least as strong as the roof system, sometimes even stronger.
If the deck is located in the place that snow slides off the roof, it better be designed twice as strong.
Another action often not considered is the impact load and vibration. That snow comes off the roof with vengeance. That sudden impact and vibration will pull the nails.
Maybe not all at one time, but each impact a little bit, then time after time, after time, eventually everything weakens until boom… everything comes apart.
Main beams and vertical posts are another common failure spot. Were the beams notched into the posts for direct bearing down on the top of the posts?
Or were they just “nailed” to the side of the posts?
Occasionally well-meaning contractors forget to go back and through-bolt the beams.
They may have used a few nails to just get things in place while building and forgot to go back and drill in bolts.
However, notching a pocket into the beam is always better than bolting to the side.
Actually, it should be both, notched in and through-bolted.
There are also galvanized steel beam to post connectors that can be used.
There are a number of really good resources about proper deck construction available for the do-it-yourselfer, also otherwise known as weekend warriors. Building your own deck can be very rewarding.
However, take your time, read up on the proper methods and materials. And oh yeah, don’t forget to get your permit.
The code office has some good reading available like what is below, just come in and ask…