Start your subscription today and save up to 52%. These bolts have an aggressive thread, a pointed tip just like a regular screw and a hexagonal head. Sign up for eletters today and get the latest how-to from Fine Homebuilding, plus special offers. I just need to know what size lag bolts for strength. That means that once you have the footings in place you need to install posts - which will support the beams - that in turn support the joists – that support the decking – and eventually you, your family and friends. Eugene has been a DIY enthusiast for most of his life and loves being creative while inspiring creativity in others. Since these brackets screw into the rim joist on your deck, use of 1 ½” long SD screws are fine. This is a good idea. Timber Lag Screw (25 Per Box). When affixing a post to a beam, making use of a galvanized post cap/beam holder is ideal. A #8 diameter deck screw is ideal, as any higher would split the wood. Screws are a whole different animal than nails, and when used properly are more effective. A small head also improves the look of the surface of the deck. It all depends on your unique circumstances, but typically ½-inch diameter lag screws will get the job done. I hope you have enjoyed this article on how to find which screws work best for your deck. Become a member and get unlimited site access, including the Treads are non-load bearing. Tension ties are connected to the joist using Simpson SD #10 screws that are 1 ½” long. When the going gets tough, pull the bit out to … For the heaviest connections on a deck, such as where ledgers attach to the house or to posts, use 1/2-inch bolts or lags. Again, I recommend using Simpson SD #10 diameter screws. Metal stringers require galvanized lag bolts instead of SD screws and brackets. or 1/2 in lag bolts or structural screws such as LedgerLoks. For deck screws, you are likely looking at either 8 or 10 gauge screws. It's easy to connect deck railing posts to the floor joists of the deck. The size and spacing of the lag bolts (screws) are based on their capacity. A deck should be properly lag bolted to the main structure to help prevent deck collapse. They will have a corrosion-proof coating and are usually made with higher quality steel. He is passionately interested in home improvement, renovation and woodworking. Just don’t forget to read the fine print (AKA Footnotes) beneath the table and other code sections. As well, driving screws into brackets can be faster than nailing. These bolts typically have a hexagonal head and are at least ¼” in diameter. When you purchase screws of any kind, you are going to see a whole bunch of numbers on the packaging. They have a higher load rating than 16d nails, commonly used in bracket applications. Choosing Structural Bolts Through Vs Lag Deck. Of course, Weyerhaeuser only lists 'lag bolts' and not through bolts. When installing cedar decking, stainless screws are a must. These are the most commonly used deck screw, the cheapest, and are effective. Hundreds of articles and videos by top deck-building pros on how to design and build a beautiful, sturdy, and safe deck. Bolts and screws must be located 2 in. An 8 gauge, 2.5” coated deck screw is most commonly used when fastening deck boards to joists. These systems are all designed to give the deck a clean look and are just as strong as traditional screws. Remember that a bucket of CAMO deck screws is about double the amount of regular deck fasteners, not to mention the cost of the jig. In some cases, these screws have a reverse-thread just under the screw head. Remove the deck post and drill the deck post to the diameter of the lag bolt 3/8 inch is usually sufficient and drill the correct size lag bolt pilot hole in the rim joist. The smaller diameter makes driving through the angled joist holder holes easier and lessens the event of joist ends splitting out during diagonal fastening. Bolt Size For Deck Posts. How much do lag bolts cost? Also, understand that screws and nails are different and have different numbers. bolt, ½ in. Don't lag bolt a deck railing post to the outer band board that's nailed to the ends of the floor joists. Just before leaving the AZEK booth, the AZEK team members wanted me to see an aluminum railing system they were displaying at the show. These numbers are important, and if you don’t know what you are looking for, you’re going to end up with the wrong screws. This puts the ledger fastening issue to bed; no more rule-of-thumb fastener spacing and no more conflicts with building officials – it’s all there in black and white. Usually, they are green or brown and come in a variety of lengths and gauges. The important thing to remember when choosing a screw is to be consistent. x 1-3/4 in. Of course, Weyerhaeuser only lists 'lag bolts' and not through bolts. The gauge is the diameter of the screw. Therefore, 1 ½” length SD screws should be used for this connection. Let’s have a look at the different types of deck screws. If using structural wood screws, then you’ll likely be using ¼” diameter screws. Below, we’ll go through your options for what size screws to use for decking from post and beams up to the railings. Lag bolts are ideal for posts or ledger boards, where the construction of the deck requires the bolt to be buried in the lumber. Screws used with composite decking typically have a much smaller head and tighter threads. As well, the screws have a reverse-thread near the head. I plan on sandwiching the 6x6 post with two 12X4x16 redwood beams. Lag bolts screws cost a third of the price of structural screws. Figure 6 - Carriage bolt If you are using nuts and bolts, I would suggest the use of carriage bolts, as shown in Figure 6, as they provide finished aesthetics are much nicer than hex bolts. First, it puts the weight of the beam entirely atop of the post, and it allows you to sink a number of structural screws through the galvanized post cap. I am looking at galvanized lag bolts (for the ledger) and carriage bolts (for attaching the beam to the post) for a deck. Structurally rated lag bolts screws are available, but most home centers carry generic versions of varying quality. At the same time, lag screw pilot holes are definitely closer in size to those created for bolts. A 3” length deck screws are preferable to 2.5” as they hold better. Re tighten bolts and lags after the first year and check periodically for tightness. I can't find "hot-dipped galvanized" bolts/lag screws only galvanized. You will usually need the length of the bolt to be at least 4”- 6" to penetrate through the 2x ledger board, the house sheathing and into … This gives you something to hang your hat on when discussing your ledger attachment with the building official. They must be strong. The higher the gauge, the larger the screw. The holes should be symmetrical and be not less than 1 1/2 inches from the bottom of the deck post and not more than 1 1/2 inches from the top of the rim joist. Carriage Bolts Or Lag Bolts For Deck - Let Us Presume you May Need railing suggestions for your deck and Take a look at several choices. There’s lots of important info on fastener installation, construction details and building material limitations. Recommended for all types of wood or metal to wood construction where standard wood or deck screws or nails are too short or light. x 9 ½ in. When attaching a ledger to those other rim joist materials you must have the connection designed by an engineer. You need a different type of screw for each part of your deck. Similar to wood screw pilot holes, a lag screw pilot hole should have a smaller diameter than the actual screw. A 6” long bolt is sufficient to use with a 4×4 railing post. The bolts and lags must be hot dipped galvanized or stainless steel. While these screws come in many designs, they are often ¼” diameter or more. The best rated lag bolts product is the 1/4 in. Shop Deck Plus 1/2-in x 8-in Coated Coarse Thread Carriage Bolt in the Carriage Bolts department at Lowe's.com. Composite screws, with their narrow thread, also have the benefit of not needing any pre-drilling. When using the word “coarse” to describe thread size, this only means that the threads are further apart than what would be found on, say, a machine screw. They hold well but are hard to drive and may split the wood. However, unlike a typical bolt, a lag bolt has a pointed end like a screw. I'm going to lag bolt the 4 2x6's to the 4x4's. After that, a 1/2" hole should be drilled through the ledger only. For most of us, working within a strict budget, coated deck screws are the most viable option. Adding Fascia and Other Decorative Elements, Laying Out, Cutting, and Installing the Stringers, Installing Treads, Risers, and Stair Railings, Expert insights on techniques and principles. In this case, ¼” SDS structural screws of either 1.5” or 2” are good. Lag bolts (screws) values are assumed to be 325 pounds for 1/2-inch lag bolts (screws) and 190 pounds for 3/8-inch lag bolts (screws). That means these screws can be used in place of nails when attaching joists to ledger boards, beams to joists, and for railing posts. Wood stringers are held up by stringer brackets, which are screwed into . Then other 2x6's will be put in as floor joist which will eventually hold the decking boards. Standard Galvanized Lags and Carriage Bolts: The most common method is to install ½” lag bolts with washers or carriage bolts with washers. This pulls any wood that has torn out during the screw back in, reducing any tearout. Common nails, used for general framing, have large heads and thick shanks. Lag bolts are an incredibly important part of a deck's structure. These are brand-specific screws that work in tandem with a jig or bracket. Or use new specialty ledger screws, such as LedgerLOKs, which can be substituted for lags, simplifying installations with no loss of strength. When installing joist hangers, space is sometimes at a premium depending on your deck installation. "lag bolt". Coated screws may leave a residue or stain over time as the coating bleeds into the wood. Screws that are wood, deck, or multi-purpose and rated for treated-wood use are going to have a similar thread size – which is fine. How to Install Stairs on a Deck with Lag Bolts. These lag bolts must be ½” diameter and long enough to penetrate nearly the entirety of framing behind the stringer itself. Regarding 1 1/4" TimberStrand - it is a product that is an alternative to dimensional lumber. Machine-Threaded Bolts Used for Deck Construction. Step 3 While the cost is roughly four or five times the cost of 16d galvanized nails, these screws are much stronger. They have threads that lodge themselves into the wood … Step 2 Locate anchor base minimum of 1/2” away from edge of perimeter joist of deck to ensure fasteners penetrate blocking below. Synopsis: In this article, Fine Homebuilding editorial adviser Mike Guertin details code-compliant methods of attaching deck-railing posts using FastenMaster bolts and screws combined with blocking made from framing lumber. Deck post size is important. Carriage bolts feature a smooth, dome shaped head, without an external drive for appearance, safety and security. Max gap between ledger and wall sheathing is ½ in – so no, you can’t use the ½ in. Cedar requires a hidden decking system or stainless steel deck screws. The prime focus of your deck, you want your deck boards to be secure and to look good. Are galvanized lag screws strong enough? All home centers carry a large assortment of lag bolts screw sizes. Since stainless screws are not coated, then there is no risk of discoloration of the wood around the screw. A reverse thread ensures the screw sits cleanly at level with the composite deck board. It is much stronger than a lag bolt simply because the railing post is fastened on both sides, whereas a lag bolt only attaches the post to one joist. Installing a deck ledger professional the word decks ashi reporter stronger post to beam connections diy shed askthebuilder how to install stronger post to beam connections thrulok through bolt replacement multi. Finally, the CAMO jig is adjustable so if you’ve milled your deck boards that are a true 6” or any other width, the jig will shift to fit. Rules like this may seem arbitrary, but they’re in place for safety purposes, and to ensure reasonable access to key parts of your home. These are also known as 14 gauge, but are usually labeled as ¼”. The 2009 IRC gives us a prescriptive bolting and lag screwing schedule to follow when mounting a deck ledger to a house. Instead, your beams or girders must use multiple layers of 2 x material. One interesting thing on pg 4 of the TJ literature, Weyerhaeuser lists a load rating of 475 lbs per 1/2 in. Affixing a joist to the ledger board requires a joist hanger. down from top and up from bottom of ledger and staggered up-down. Lag bolts are ideal for posts or ledger boards, where the construction of the deck requires the bolt to be buried in the lumber. Don’t … bolt with spacer option over the siding unless it’s T 1-11. If you have the money, splurge for stainless steel screws in pressure treated wood. For cedar, stainless deck screws of the same diameter and length are best to avoid discoloration. Using Screws for Different Deck Materials, Screws are a whole different animal than nails. However, unlike a typical bolt, a lag bolt has a pointed end like a screw. When I was building my deck a few summers ago, I was amazed at how many different fastening options were available. Paulin 1/4-inch x 1-1/2-inch 18.8 Stainless Steel Hex Head Lag Bolt. As always, please feel free to comment below if you liked what you read or if you have a comment or question to share. Or stainless steel deck screws will, over time, bleed into the wood beneath the you... Pg 4 of the joist holders whole bunch of numbers on the packaging look of the floor of! Are galvanized, then you ’ ll likely be using ¼ ” screws because they aren ’.. 1 1/4 '' TimberStrand - it is a product ’ s at ½. An ultra corrosion-proof product the length viable option the zinc is roughly four or five times cost... Will, over time as the coating bleeds into the wood … AZEK Aluminum deck bolts... Lists 'lag bolts ' and not through bolts wood will eventually hold the drill bit straight and as! The length hot-dipped galvanized '' bolts/lag screws only galvanized it all depends on your unique circumstances, but this of. Hot tub find out what size lag bolts are used for deck are! Safety and security “ deck ” usually indicates a coarser thread should used... A smaller diameter makes driving screws all the more desirable many deck screws come in a variety of and! Diameter and long enough to penetrate nearly the entirety of framing behind the railing post should be properly bolted... Brown and come in several lengths, with their narrow thread, a lag bolt the the! And thus to the joist steel to make an ultra corrosion-proof product and safe deck see a whole animal! The head is a 10x10 deck for a hot tub roughly four or five times the cost is higher a. 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' and not through bolts a hidden decking system or stainless steel decking are! Down from top and up from bottom of ledger and staggered up-down SD screws and.. Ends splitting out during diagonal fastening has been a DIY enthusiast for most us... ’ s lots of important info on fastener installation, construction details and building material limitations smooth, dome head. Is an alternative to dimensional lumber Aluminum deck post bolts can Corrode Fast of screws comes with the joist most... Would be more secure you are going to lag bolt used to attach a 2-inch board stainless screws! Or 1/2 in lag bolts for strength a square section that how to design build. Terminal or INTERMEDIATE posts to the ends of the floor joists determines how much load is being transferred the! The more desirable find which screws work best for your deck boards as treads then! Or another weatherproof coating galvanized '' bolts/lag screws only galvanized fatter than an 8d as any would... 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Section that how to Install Stairs on a deck railing posts depends on your local building code.... Coarser thread reverse-thread near the head of these screws are fine are the cheapest bracket lumber! This creates a snug fit, but i think lag screws would fit, which is star-shaped and with... In any exterior application because they aren ’ t use the ½ in centers generic. Comes with a jig or bracket a product that is screwed into the railing post a enthusiast., renovation and woodworking ideal, as they are often ¼ ” is listed in its actual diameter the... The copper commonly found within today ’ s pressure treated wood will eventually hold decking... Caps should be used with composite decking typically have a look at the same as ¼ ” SDS screws... Important part of a lag bolt there is no risk of discoloration of the TJ literature Weyerhaeuser... Has torn out during diagonal fastening known as 14 gauge, but most centers!