A well-designed, well-built deck can transform a yard in all the best ways. But proper deck construction requires the right materials. You can't just throw one together using whatever's in your garage or tool shed and expect it to be safe for you, your family and your friends. Unfortunately, decks not properly installed can collapse under heavy loads, which of course can pose a danger to anyone in the vicinity.
In most all cases, decks are connected on at least one side to a building, house or some other sort of structure. The type of fastener you use for this connection is vitally important, and the safest and most common type of fastener used is the lag bolt.
Why use lag bolts for decks? For a number of reasons.
Using Lag Screws and Bolts for Building Decks
The first thing you should know is that a piece of wood connects a deck to a structure. This piece of wood is known as a “ledger board,” or a “ledger” for short. Lag screws are the traditional and recommended way to attach the ledger to a building.
What size lag screws will you need? It all depends on your unique circumstances, but typically ½-inch diameter lag screws will get the job done. First, pre-drill 5/16-inch holes through both the rim joist and ledger, then drill a ½-inch hole through the ledger alone. You need lag screws that are long enough to extend beyond the band board by at least a half-inch.
You must know what you’re drilling your lag screws into. As mentioned, a rim joist is the ideal part of a building to drill them into, but there’s not always a rim joist to attach to when you’re building a deck. Avoid attaching your lag screws into a building’s drywall or fiberboard, as these materials won’t be strong enough to support the weight of the deck and those standing on it — you’re just asking for the deck to collapse.
Lag screws are fairly inexpensive, which is a bonus. But be sure to get stainless steel or hot-dipped galvanized screws for optimal performance. You can invest a little bit more to get lag screws that require no pre-drilled holes. These special lag screws often have washers attached to their heads. Also, if you can get behind the rim joist of the house, you can use through-bolts as an alternative to lag screws. Use carriage bolts to secure your deck to the house, then secure the carriage bolt in place by attaching a washer and nut on the opposite side of the rim joist.
Never use nails to attach a deck to a rim joist, as nails can’t offer the stability needed to hold the deck, much less people standing on top of it.
Keeping You Safe
The No. 1 challenge in building a deck is the safety of those who are going to use it. When decks are suspended in the air, this is particularly important. But even decks built low to the ground can pose significant safety issues if not properly installed. Never take shortcuts when building a deck. It’s tempting to fasten to fiberboard, use nails or even chisel out a portion of the rim joist so carriage bolts that are too short can be capped with nuts and washers. But each of these shortcuts will damage the integrity of your deck and lead to situations that are dangerous for you, your family and your guests.
The Best Bolts for Pressure-Treated Wood
Pressure-treated wood uses chemicals that can accelerate the appearance of corrosion unless you use the appropriate fasteners. When building a deck that features pressure-treated wood, use galvanized screws whose galvanizing thickness is between .75 and 1.5 millimeters. Look for galvanized materials from A153 to F2329 to achieve this thickness.
While you may hear that you need double- or triple-dipped galvanized fasteners, this is a misconception. In reality, double- or triple-dipped galvanized fasteners will need a zinc coating to be useful in deck construction.
About FMW Fasteners
When you need bolts for building a deck, come and discover the wide selection of fastening materials you’ll find at FMW Fasteners. We offer this huge selection so construction professionals and do-it-yourself enthusiasts always have access to the high-quality materials they need to deliver outstanding results on projects of all kinds.
You can always enjoy quick shipping when you shop with FMW Fasteners — and orders over $25 ship free. Order bolts for decks in the exact quantity you need rather than the fixed amounts other providers insist on. If you have bolts or screws left over after your project that you don’t need, you can return them at any time as long as they remain in like-new condition — there’s no expiration on returns.
Make sure your deck is the venue for outdoor enjoyment that it should be. A quality project demands quality materials, and that’s just what you’ll find at FMW Fasteners. No matter the size, specifications, and metal type that you need, you’ll find multiple options in our generous selection. Choose FMW Fasteners when you need only the best bolts for building a deck.