What is the best joist spacing for a deck?
In North America, joist spacing for residential decks is 12″ to 16″ apart, or according to local building code. Most decks require 16″ spacing for the deck itself, with 12″ spacing used for special applications, such as stairs or commercial structures.
Should I use 2x6 or 2x8 for deck joists?
That's a model deck code which includes joist span tables. If there is to be a railing, you need the joists to be at least 2x8s. 2x6s don't have the depth needed to resist the leverage that can be placed on a railing post bolted to them.
What is the maximum span for a 2x6 deck joist?
Larger joists can span across wider areas. For example, a 2x6 joist would have a 12-foot, 6-inch maximum span, and a 2x10 joist would have a 21-foot maximum span.
Can deck joists be 24 inches on center?
The deck joist spacing can range from just 12 inches to 24 inches, though it's important to check the local building codes to determine if your deck meets the standards for a safe and structurally sound build. Use this guide to learn how to calculate deck joist spacing.
What is the minimum spacing for decking?
A gap of 10mm between deck boards and external walls of adjacent buildings is recommended for drainage. Board spacing depends on the width of the board but a guide is 3-4mm for 90mm boards and 5-6mm for 140mm boards. Note that if wet decking boards are laid, when they dry out the gaps between them will increase.
What size joists for decking UK?
What Size Joists Do I Need? If it is a standard deck with just a table and chairs sitting on it, 4 x 2" (100 x 50mm) joists are strong enough. However, if you are looking for strength and are putting heavier objects on the deck, we would recommend 5 x 2" (125 x 50mm) or 6 x 2" (150 x 50mm) joists.
Are 2x8 strong enough for deck joists?
2x8 for joists will be fine, with 16" OC. Should use 2x10 for beams but 2x8 will be fine as well. If you are worried you can triple the 2x8 for the beams but double will be sufficient. You should put the beams at 7 and 14 feet out from the house, with the piers you should do 3 per beam with spacing of 1, 7, 13.
Are 4x2 joists OK for decking?
The frame The key to constructing a good decking area is the frame. If the decking is being built on a low level it should be built of C16 graded treated joists 45 mm by 95mm (4×2 approx.). However if you are building a raised deck you should use 45mm x 145mm joists.
Are 2x6 strong enough for deck joists?
Can I use 2x6 for deck joists? If the span is only 8 ot 9′ then yes, they will work. You would be better to check the national building code - joist spacing - before you buy your lumber. LLive loading on a deck is estimated at 40 pounds per square foot (10 psf for static load) usually.
How far can a 2x8 joist span without support?
The maximum span of a 2x8 floor joist depends on several factors, including the wood species, grade, spacing between joists, and the expected load. In general, for residential construction using standard framing lumber such as Douglas Fir-Larch, a joist can span approximately 10 to 13 feet when spaced 16 inches apart.
Can I use 2x6 for deck boards?
Deck Board Size
2x4 and 2x6 are thicker and stronger, but they also tend to be more expensive than a 5/4 board of the same width. Most manufacturers offer composite decking boards in 12', 16' and 20' lengths. The width varies by brand and style and can range from one to two inches thick and four to six inches wide.
How far can deck joist span without support?
It depends on the spacing of the joists, as well as the type of timber. First grade yellow pine at 12″ centres would be 12 ft 6″, 16″ centre 11ft 4″ and 24″ 9 ft 11″. Douglas fir would be 12 ft, 10 ft 11″ and 9 ft 7″ respectively. Similarly spruce is 11 ft, 10 ft and 8 ft 9″.
Should I use 16 or 24 joist spacing for deck?
Deck joist spacing should never exceed 16″ on center (with the exception of MAX deck boards, which allow for maximum 24″ on center). For a more rigid feel, 12″ or less may be preferred. If adding additional framing, be sure to keep all boards level and in plane across the tops.
Do I need blocking between deck joists?
Blocking required every 4' - 6'. Blocking must be equally spaced in rows, maximum of 4 to 6 feet apart. WHY IS BLOCKING NEEDED? Solid wood blocking will help reduce up or down movement and/or twisting of joists.
Do deck joists have to be perfectly level?
Uneven Deck Joists
Your deck might look wonky if the joists were not adequately leveled at the time of framing and squaring, or they may have become weak over time. You might be able to remove the deck boards over the problem area and plane down or replace problematic joists.
How do I calculate deck spacing?
Decking Joist Spacing
Decking joists should be spaced at 400mm centres. Structural posts should be positioned no more than 1800mm apart. Use a joist and spirit level to mark the ledger height at the wall. Joists are attached to the ledger or double beam with galvanised joist hangers.
What is the spacing for decking timber?
Decking boards span from joist to joist. If you use 5/4 decking, joists must be no farther apart than 16 inches. Decking with boards with a 2x4 or 2x6 span can be 24 inches. If you run decking at an angle, you might need to put the joists closer together.
How far can 1 decking span?
Our top of the range 100mm Decking Joist is perfect for constructing a sturdy decking frame that will stand the test of time and come pressure-treated with TANALITH E. Need some help with your decking project? Check out our Garden Decking Construction Guide HERE.
Can I use 100mm joists for decking?
Readily available decking boards are machined from nominal 100 x 25mm or 75 x 25mm timber planks for which joist spacing of 450mm would be acceptable.
What is the joist spacing for 25mm decking?
Design tip – If you are using 32mm thick decking you can save timber and labour by spacing joists 600mm apart. If you're using hardwood or other decking thats 19mm thick the joist spacing will have to be reduced to 450mm centres or less.
What is the spacing for 600mm joists on a deck?
For most decks, post size is overlooked unless an inspector notices the unusual height of a particular deck. A short 4x4 can carry an awfully big load, and many deck builders use 6x6 posts as a standard, regardless of the height or load of the deck.
Are 4x4 posts strong enough for a deck?
Species and grade of wood can influence the span, as well, as the live and dead loads and joist spacing. If I were to use the typical Douglas Fir #2 or better, 40 psf live load, 10 psf dead load, and 16"o.c. spacing, the maximum span that I calculated for a double 2x8 would be 16 feet.
How far can 2x8 span on a deck?
Composite decking can crack if screws are placed too close to the end of the board. Planning ahead for the butt-joint location and installing a double joist there is a great, inexpensive way to avoid that problem.
How far can 2x8 joists typically span?
Standard spacing between joists can be either 12 or 16 inches on center (OC) depending on the length the joists need to span, so homeowners will need to divide the width of their deck (in inches) by 12 or 16 to determine the number of joists required.
Why double joists for deck?
We recommend building an elevated substructure with posts and footers for improved durability and water resistance. Sleeper systems install joists directly to the concrete, so your deck will inherit any flaws in your concrete slab, including sinking, shifting, and uneven installation.
How do you calculate joists for decking?
I have built many decks for new homes with them. 6x6 is more sturdy of course and will not twist as easy, but for structure purposes, 4x4 will be fine. I would just not go more then 10' apart with them. My son inlaw had a carpenter use 4x4 pressure treated beams that are about 9 or 10 feet high for his deck.
Can decking joists sit on concrete?
A 2x4 as a deck joist would be limited to 4' or 5′ of span on 12″ centers. Any further the deck will not feel solid when a 200lb + human is walking on it. A lot depends on how the supporting structure is designed.
Can 4x4 be used for deck joists?
2x6 lumber should never be used for joists that span open air. Even on a deck. They're fine for fully supported floors, such as with full-contact rock or gravel bed foundations. Then, since you're using those footing blocks it's not so much a matter of lumber size, but of footing interval.
How far can a 2x4 deck joist span?
2x8 for joists will be fine, with 16" OC. Should use 2x10 for beams but 2x8 will be fine as well. If you are worried you can triple the 2x8 for the beams but double will be sufficient. You should put the beams at 7 and 14 feet out from the house, with the piers you should do 3 per beam with spacing of 1, 7, 13.
Can I use 2x6 for deck joists without?
Structural Jacks & Beams
Long joist spans and poorly planned structural layouts cause more sagging floor joists than anything. If the beams are spaced too far apart, the long floor joists are probably stressed and bowing under the weight of the home and gravity.
Should I use 2x8 or 2x10 for deck?
On BestDeckSite, we recommend installing blocking on 2x8 joists too. Here's a word of caution. As you get on a roll calling out numbers for the guy at the saw while hammering in the preceding block, make sure not to throw off the joist spacing.
What if joists are too far apart?
That's a model deck code which includes joist span tables. If there is to be a railing, you need the joists to be at least 2x8s. 2x6s don't have the depth needed to resist the leverage that can be placed on a railing post bolted to them.
Do 2x8 joists need blocking?
The general rule of thumb for standard deck fasteners is 350 screws for every 100 square feet of decking, which is based on standard 6" wide boards (5-1/2" actual), and 16" joist spacing.
Is it better to build a deck with 2x6 or 2x8?
Fastener length is easiest to determine, since it is governed by the thickness of the decking itself. Standard 2x4s or 2x6s require a 3 in. L fastener, while 5/4x4s or 5/4x6s only require a 2-1/2 in. L fastener.
How many screws for 2x6 deck boards?
When installing new air-dried decking the proper gap ranges from 1/8 inch (3.5 mm) – 1/4 inch (6.5mm) depending on the environment. If you are installing air-dried decking during a rainy or humid season you may want to place the boards with a 1/8 inch (3.5mm) gap.
How long deck screws for 2x6 decking?
See FIGURE 2 through FIGURE 4 for joist span types. Use TABLE 1 to determine your joist size based on span length and spacing. The maximum overhang is equal to one-fourth of the length of the joist span (0.25 x joist span).
How do you fix uneven deck joists?
A gap of 10mm between deck boards and external walls of adjacent buildings is recommended for drainage. Board spacing depends on the width of the board but a guide is 3-4mm for 90mm boards and 5-6mm for 140mm boards. Note that if wet decking boards are laid, when they dry out the gaps between them will increase.
What is the maximum space between deck boards?
For example, a 12-foot x 12-foot deck of 5/4 x 6 pressure treated wood decking on 16 inches on center spacing of joists will require: A 12-foot long deck with joists 16 inches on center will require 10 joists. 20 fasteners x 26 (number of rows of decking) = 520 fasteners. Add 10 percent to be safe.
What is the maximum overhang for deck joists?
2x4 joists would be sufficient depending on close they are spaced (no further than 12" on center, maybe even a bit closer) and how long the 2x4s will span from one support beam to the next. 2x4s can not span a very long distance without starting to bend. You might consider using 4x4s as sleepers.
What is the minimum spacing for decking?
Some deck builders install blocking throughout the frame to increase the strength of long joist spans and promote a more solid structure. Often times, scrap materials from your framing lumber may be used for blocking. Always make sure that this material is either pressure-treated or naturally resistant to decay.
How many joists do I need for a 12x12 deck?
Nails or screws both work fine for this. You might look at whether the subfloor (lumber or plywood) joints needed the additional splices for support. If the 2' splices are above the existing joist (which your description sounds like) they were installed in an attempt to level the floor due to sagging joists.
Can you use 2x4 for deck joists?
Without the right deck spacing, the boards may expand, cup, and buckle out of place. As a result, you may have to replace broken decking, or reinstall the boards with wider spacing to prevent further cupping and buckling, which can be time consuming and expensive.
Does blocking make joists stronger?
Always make sure your joist, blocking and any added framing are even and in plane with each other across the tops. Proper joist spacing is required for proper installation. Joist spacing should never exceed 16” on center unless using TT/AZEK Max board= 24" max. For a more rigid feel, 12” or less, may be preferred.
Can you use screws for joist blocking?
The maximum suggested span for 19mm hardwood decking is for joists to be at 450mm centres. Board spacing should allow for air circulation and drainage and also take into account seasonal movement. All timber will shrink as the timber dries and swell as it takes on moisture.
What happens if you don t leave a gap between decking boards?
Can I use 2x6 for deck joists? If the span is only 8 ot 9′ then yes, they will work. You would be better to check the national building code - joist spacing - before you buy your lumber. LLive loading on a deck is estimated at 40 pounds per square foot (10 psf for static load) usually.
How far can a 2x6 deck joist span?
Deck joist spacing should never exceed 16″ on center (with the exception of MAX deck boards, which allow for maximum 24″ on center). For a more rigid feel, 12″ or less may be preferred.
Do joists have to be evenly spaced?
What Gap Should You Leave Between Decking Boards? The size of the gap you leave should be between one quarter to one eighth of an inch (6.35mm to 3.175mm). If you're installing the decking yourself, you can use something for reference to ensure the gap is consistent across your surface.
What size joists for 10x10 deck?
Readily available decking boards are machined from nominal 100 x 25mm or 75 x 25mm timber planks for which joist spacing of 450mm would be acceptable.
How do I calculate deck spacing?
What is the joist spacing for 32mm decking?
What is the joist spacing for 19mm decking?
What is the spacing for 600mm joists on a deck?
Are 2x6 strong enough for deck joists?
Can deck joists be 24 inches apart?
What is the best gap for timber decking?
Deck joist spacing should never exceed 16″ on center (with the exception of MAX deck boards, which allow for maximum 24″ on center). For a more rigid feel, 12″ or less may be preferred. If adding additional framing, be sure to keep all boards level and in plane across the tops.
What is the joist spacing for 25mm decking?
The maximum span of a 2x8 floor joist depends on several factors, including the wood species, grade, spacing between joists, and the expected load. In general, for residential construction using standard framing lumber such as Douglas Fir-Larch, a joist can span approximately 10 to 13 feet when spaced 16 inches apart.
Should I use 16 or 24 joist spacing for deck?
Composite and softwood decking will follow the 16" on center rule, but hardwood decking can handle greater spans with similar dimensions. For example: 5/4 x 6 cedar can span 16" on center, but Ipe can be a 1 x 6 dimension for the same span. 5/4 x 6 Ipe can actually span 24" on center.
How far can a 2x8 joist span without support?
A 2x4 as a deck joist would be limited to 4' or 5′ of span on 12″ centers. Any further the deck will not feel solid when a 200lb + human is walking on it. A lot depends on how the supporting structure is designed.