For example, a 2 x 12 joist placed 16” OC. Joist Size for Hot Tub Deck. The size of the beams and the span between beam support posts, plus the distances between beams and ledger, affect the distance joists must span. Thanks so much...this is such a valuable forum....really appreciate you taking the time to provide QUALITY answers. It offers greater strength and allows joists to be spaced up to 24”o.c. You can mount them using metal hangers made for this purpose. The IRC reflects proven construction techniques for wood decks using widely accepted conventional construction materials and practices. Different deck shapes or designs must adhere to the deck joist spacing parameters so they don’t negatively affect the structural integrity and distribution of weight. The distances deck joists must span and their spacing influence the size and grade of the lumber, and vice versa. A new platform with large footings at least 22" in diameter should be installed below each corner of the tub to evenly distribute the weight. High Strength: Douglas fir and southern yellow pine will span greater distances. I hope you have a better understanding of material selection for framing a deck and how Codes can be used to ensure the deck is structurally safe and sound. Obviously you can tweak it for your own design, but our free deck blueprint is a good start. Re: Hot tub load on existing deck I had to go through things like was the hot tub going to be fixed or portable, was it going to be hardwired or plug 120 V or 240? However, if your deck will include a hot tub or roof, you must support that weight with additional footings. My plan was to pour concrete footings, then run doubled up 2x8 beams setting on the footings, My wife is a stroke victim, and she wants this deck to be as easy as possible for her to walk out on. Joist size determines span and spacing, so select the grade and type of wood best suited for your needs and budget. Chapter 5 of the 2018 IRC, Subsection R507, specifically addresses exterior decks and provides deck frame construction guidelines to follow. Elevated decks often require greater post and beam support for shorter deck joist spans. Hot tub or spa decks should always be "overbuilt". spacing is half the span plus two. The boards and furnishings rest on a deck frame of joists supported by beams, ledger, posts, and footings – all are important. Join in and write your own page! or less if the decking is laid perpendicular, or 12”o.c. The live load is the weight of everything placed on the deck – furnishings, plants, people, etc. This brings us to the next part of the puzzle. The shape determines post and beam placement, spacing, and dimensions. With the deck being 3 feet high On one end, this qualifies for "permitting" and should go through your local building regulatory office. I'm going to put a hot tub on the deck, on one end. Lay out a perfect 8 foot square at the location you plan to build the deck. can span 9’-11” but that drops to 6’-8” with a cantilever. Never place a hot tub on an existing deck that wasn't designed to support the massive loads. 10-04-2013, 10:15 AM. 2. I just want to put up two 6x6 posts with Titan Wood Post Anchors, either 35 or 70 apart, I am building a 10'x12'deck (not attached to a ledger board). Also, there will be wooden girders running perpendicular to the joists. They should be the same, about 11' 3.5" 3. the span maximum is 9’-1”. The joist spand between these main beams with a couple screws to set them in place and after joist hangers were added. In this guide, we’ll discuss joist sizing, spans, spacing, and factors that affect material selection when framing a deck. 7. Pound a stake at the center location. Decking may be perpendicular or diagonal to joists, full run or staggered, or something unique. The average 8' x 8' hot tub weighs over 5,000 lbs when filled with water and people. at right angles. Select the Lumber Species or Type – Southern Pine, Douglas Fir, Hemlock, SPF, Redwood, Cedar, etc. There will often be a number of acceptable combinations of joist size and spacing… Knots and defects affect the strength of the timber, making it weaker. Some formulas take the bending, compression, and breaking values for wet or dry wood that are based on predetermined values for different species to determine safe loads over specified distances. Mount the 4x4s perpendicular to the existing joists beneath the deck. Join in and write your own page! Downsizing to 16”o.c. He writes: I am building a deck that will hold a fiveperson hot tub. Joist blocking spacing at half or third points strengthens the deck frame by improving the connections and distributing forces to more support members. See all of our free deck plans here. All are common methods and may affect the overall design and cost of the project. I just figured a deck for a guy with a hottub that is around 2600 lbs when filled with water. A quick rule of thumb for determining joist thickness for 12”o.c. See Using These Tables and Design Assumptions for additional information. Strengthening a Deck For a Hot Tub. Designing a deck specifically for a hot tub requires a lot of forethought. Tub = 7.5'x7'= 52sqft 6500lb loaded and people Deck = 10ft joist span + 2ft cantilever 2x10x12 joist, 16" … 8' MAX JOIST SPAN a: 16' MAX JOIST SPAN a: 5 / 8" Hot-dip galvanized bolts with nut and washer b and 12d Common hot-dip galvanized nails c: 1 @ 3'-6" o.c. Lumber Species. Tags: deck, hot tub, joist load. Factors that Determine Deck Joist Spacing and Span, How to Determine the Proper Deck Joist Sizing and Spacing, 4. The cantilever reduces the span but usually increases the overall length of the joist that may be used. I am about to install a hot tub on our deck that will need to be extended. Simply click here to return to. Additionally, the beam support structure, type of deck board desired, the pattern for installing the decking, and of course, the Building Code must be factored into the decision too. Codes address all aspects of residential construction, not just decks. The joist spand between these main beams with a couple screws to set them in place and after joist hangers were added. The dead and live load the deck will carry helps set the span and spacing of joists and joist dimensions. It also determines if joists will be cantilevered which also affects the span and spacing. Well I am glad you found the deck footing load calculator helpful. The fact that the deck has not collapsed under the weight of the hot tub is amazing. With the deck being 3 feet high On one end, this qualifies for "permitting" and should go through your local building regulatory office. This calculator determines the size of each tributary area of your deck. Most decks use dimensional 2-by lumber which is more readily available. can bridge 18’-6”. Deck Load Capacity . It is available pressure-treated at a premium price. hot tubs are beyond the scope of this document. The joists are usually not visible, so using expensive premium timbers isn’t necessary as long as the beam structure is properly placed. How much weight can your deck safely handle? The more complete the plan, the fewer surprises. Spacing also impacts the distribution of weight, influencing the structural strength, and deck integrity. How? TABLE R507.5. Here they may require, an engineers "stamp" for the hot tub … Deck boards that diagonally cross joists at angles such as 30°, 45°, or 60° span a greater distance, and so the deck joist spacing must be adjusted. Home > Joist Span Calculator. Default is 50 psf which you can change. Additionally, though, the values are also influenced by many factors, including wood species and grade. But decks 2 feet or higher will need added support. Placing the beam so the outside face is 12’ from the structure or 10’-6” doesn’t affect the cost, but does impact the structural strength. For help, simply click on the beside the section you need help with, Or watch this Tutorial Video. This deck includes plans for built-in benches flanking the hot tub. The overall load is made up of the dead load and the live load. See more ideas about deck, building a deck, diy deck. A deck is an outdoor living area and enhances the look and character of a home. The distance of the beam from the ledger determines the deck joist span. Support Post Spacing for Eventual Hot Tub on Deck. This top tips for building hot tub decks post is from the experts at Real Cedar.com, check them out to see why you should consider authentic cedar for your deck.. The greater the span and spacing, the more spongy a deck may feel. There could be safety reasons too for having the top welll above the deck. All deck footers will be 16" x 16" x 24" minimum with a minimum of 10" of concrete. Â© 2004-2019 Decksgo.com. Southern pine is stronger than most other common deck construction wood types and offers the greatest span. Hi guys I have started building a 2.4x2.4 deck for a hot tub. How many joists, what size, spacing, and how many posts do I need to ensure the heavy tub wont settle the deck? The shape often determines the direction of the joist grid, which in turn affects the deck board layout and direction. As hot tubs have become increasingly popular to install in gardens across the country, decking has become the platform of choice. It is important to note that not all values in some tables are the same as what is in the IRC, so it is important to check the local Code for accurate current values for your area. On Center Joist Spacing 12" 16" 24" Overhang? Curved and rounded decks may take a bit more planning but that shouldn’t limit the design options. Many reflect the information found in the IRC or National Building Codes. I would use a 2 2x12 to make a beam for the girders and use 2x10 joist at 12 inches on center all attached with metal brackets. We’ll also explore how they influence the strength and safety of a deck. I took the weight and converted it into PSF and then to PLF, added it where the tub sits on the joist and came up with 2x8 SYP #1 at 12" O.C. We recommend this joist span calculator, which has the following functions: Deck joist span tables commonly identify the maximum span for different wood types and joist spacing. – and is normally rated at 40psf. With the input of the three factors, the algorithm provides the maximum span. For joists I would go with 2 x 10 for the entire project and for under the tub use a "tic tac toe" type of joist grid. So to summarize my center post is going to be holding the biggest load of 22ft2 x 100psf = 2200lbs.I've had no problems calculating my footings (10" diameter and 4' depth) and post (6 x6)....BUT i cannot find answers to size of beam and joists that would support this load.I'm using prem pt lumber thats made from spruce... HOW CAN I FIND ANSWERS TO THESE SPECIFIC ENGINEERING QUESTIONS?your help is greatly appreciated. I used your DECK LOAD calculator (excellent tool by the way)to add more support piers. joists (just in tub area) is more than enough. The 2018 IRC is a good place to start as is your local Code which may adjust values or loads for regional conditions. In many building supply stores, the choice of grade and type is limited. We recommend beams are constructed from two 44 x 145mm Q-Deck deck joists and are placed at maximum centres of 1.8m. It then determines the total load from each tributary area based on the design load of your deck. Living in a region with heavy snow loads or winds can also increase the live load values, and so should be included in the design considerations when building a deck. Dimensions stated represent the maximum length of unsupported joists (ie. Common spacing (how far apart each joist is from the next) for decks are 16 inches, 24 inches or 32 inches on center. The span of the joist (how long a joist is between supports) is determined by the same factors. Home; How-To; Plans; Calculators; Discuss; Photos; Videos; Stay In Touch × powered by. For example, a 2 x 12 joist placed 16” OC. For demonstration purposes only. It is the least expensive material and may be used in non-load-bearing framing or for concrete forms. Choose Material and the Size for Your Joists, Example: How Far Apart to Place Deck Joists for 12 x 12 Deck, SPF #2 Grade Joist Configurations for 12–foot deck. For example: half a 10-foot span is 5, add 2 is 7. It also permits the use of 2x8s at 16”o.c. Joist ends and bearing locations shall be provided with lateral restraint to prevent rotation. The cost difference between 2x8s and 2x10s is approximately $7.00 each. Check out our table below which is based on the information on Table R507.5 of the 2018 IRC. Here’s what I’ve discovered: Yes, you can put a hot tub on a deck. To determine the correct joist required, we need to establish the spacing of our joists. Round the span to the nearest foot and add two. for boards laid at an angle to the joists. DECK JOIST SPANS FOR COMMON LUMBER SPECIES (ft. - in.) They support the deck surface and provide a level framework to which decking is attached. A 2×6 yellow pine at 16”o.c. As far as the post size i can not size them i do not know the heigth of the deck or were the tub will set on the deck. The design utilizes a double 2×12 beam with 6×6 posts spaced 6-feet apart, and ledger with joist hangers. The joists need to be spaced 16”o.c. and 2 @ 8" o.c. Blocking is also frequently used to create a frame or racetrack to support deck board designs such as picture frames, herringbone, zipper, parquet, and diamond patterns. OR: Self-drilling screw fastener d: 12" o.c. You can order the grade and type you want, but it often is more pricey. I used 2x12 joist doubled every 14" apart the beam on the outside is a 6x12 sitting 6x6 posts with a footing 25x25 by 3 feet deep with simpson post base. Deck joists shall be permitted to cantilever not greater than one-fourth of the actual, adjacent joist span. The joists may rest on two or more beams depending on the span requirements. Your comments and suggestions are always appreciated. The joists are fastened to the beams to maintain spacing and prevent movement. spanning 16’-6” between supports may cantilever up to an additional 4’-1 … It also improves the structural strength of the deck. Choosing the right decking material is just as important as choosing the right hot tub. Spacing may be less, but shouldn’t be more. The deck must be low to the ground. Lumber grades further identify the strength of different wood. The height available from ground level to entry-level may trigger the need for landings or the inclusion of a lower deck. And hot tubes are heavey. It’s best to adhere to the Code or involve a Structural Engineer. Joists can usually span up to 1.5 times their thickness in feet. Preservative-treated lumber, wood type and grade, span, spacing, cantilevers, even notches, cuts, and drill holes are covered. by Bob I have an 12x24ft deck,5/4 decking with 2x8 floor joists 16oc. All you have to do is input the information, press calculate, and the maximum span is identified. for perpendicular and 8”o.c. The grade, wood type, spacing, thickness, and width determine the distance joists can safely bridge. Deck joist spacing for composite decking is the same as that for 5/4” boards. There are many considerations before undertaking a … Choosing the right decking material is just as important as choosing the right hot tub. "O … read more. or 16”o.c. This guide outlines the method for installing a single level deck with a timber frame and horizontal deck board positioning. That affects the joist and beam directions, as well as the live load requirements. The area under the hot tub should be framed as a separate system, with its own footings. It's easy to do. Size and spacing depend upon the shape and size of the deck, the weight it needs to support (hot tub? There are so many variables and potential for error when calculating from scratch, that unless you’re a Structural Engineer tasked with the job, it’s better to use another method. Adding a hot tub or spa to the deck will increase the live load and affect deck joist span and spacing. The spacing and span of joists that support the decking are identified in most Building Codes. by John Stuart Wrap a string around the corner stakes and make two diagonal strings to locate the center. Otherwise click the each image below to enlarge. Living in a region with heavy snow loads or winds can also increase the live load values, and so should be included in the design considerations when building a deck. Re: Hot tub load on existing deck. Decks commonly follow the perimeter of a wall or structure, or the contours of the landscaping, or both. How to Build a Tub Support. with a live load rating of 40psf will span 9’-9” while a 2×12 yellow pine at 16”o.c. Regardless of the span, 2×6 joists are usually limited to ground-level decks without railings. If you found this guide helpful, please share it with others. Joist installation doesn’t impact the spacing between joists, but it does affect the span. The tub weights around 1-2 ton in weight full I have installed 9 4x4 post and timber framed it up the post have Been concreted in a good 14 inch down x 12 x12 wide until I hi a solid surface. on an angle. All Rights Reserved. Adding a deck to a home or yard is a great way to create an outdoor living space. Joists that cantilever allow for the use of longer joists than those that terminate at the outside face of the beam. There is an increase in cost due to more joists but it’s usually marginal in the overall cost. Manufacturers of different composite decking products commonly include instructions with their products. Most deck builders use scrap or unusable joist boards to cut into blocks for use at mid-span or 8’ spacing between beams. Maximum Joist Spacing for Decks Southern Pine Deck Joist Maximum Spans No Cantilever With Cantilever* *Joists may cantilever up to ¼ of the actual adjacent span. Deck joist spacing is the distance between joists, measured from the center of one joist to the center of the next, and is commonly 12, 16, or 24-inches. Hot tub measures 80" square. You can use the plan below to construct a hot tub deck in one afternoon. A Joist Span calculator commonly identifies the maximum span and cantilever for dimensional lumber joists based on wood type, joist size, and spacing between joists. The dead load is the weight of all the building materials and is commonly calculated at 10psf. Before you get swayed by features such as colored LED lights, integrated cup … Southern pine with a select or #1 grade is stronger than #2 grade SPF and can carry more weight and span a greater distance. Oct 13, 2020 - Explore PlasticineHouse - DIY Projects's board "How To Build a Deck", followed by 6199 people on Pinterest. The live load also affects the footing size. I want to make sure that this deck has plenty of support. For example, a standard outdoor deck will not be required to support as much weight as a dining room floor, unless the deck with have a large hot tub. Incising is the process of infusing preservative deeper into the wood through small 1/4” deep cuts on all surfaces. Once the plan is complete, a material list can be generated for building materials. The deck … Simply click here to return to Pools and Hot Tubs Forum. However, if your deck will include a hot tub or roof, you must support that weight with additional footings. I am looking to install privacy screens on my concrete patio. It requires two 3” or 3-1/2” fasteners in every joist and is also spaced 1/8” to 3/8” apart. Because decks shack. Step 4 - Place the Footers. Although this requires quite a bit of effort, it is much less expensive than outsourcing the job to a professional company. The more elaborate the decking plan, the greater the joist structure requirements. Although 2x4s may be used for low-profile joists near ground-level they aren’t normally included in structural joist tables. Joists commonly are spaced at 12”, 16”, or 24” centers depending on the load the deck frame will carry and the size, type, and orientation of the deck boards. Deck joists, similar to those in any structure, determine the load a floor or deck framing can carry. It is also less expensive than select or #1 grade wood. According to the manufacturer, the weight of the filled tub with five people in it will add about 94 pounds per square foot of weight to the deck over a 45- square-foot area. There are six main factors to consider when designing and building a deck that determines the span and spacing of deck joist. or less if diagonal to prevent sag and bounce. It doesn’t affect the strength of the wood and is available in 2-by and 5/4 decking formats for decking and frame construction. The spacing between joists is 12”o.c. This is not an option, deck finished height will be about 1+' from the ground level. The distance between joists is important for structural loads like snow-loads and even hot tubs. ), and the height off the ground. The average 8' x 8' hot tub weighs over 5,000 lbs when filled with water and people. Because of this extra length I added cross bracing to tie them together and stop the boards from twisting or propellering. Check with local building code to determine spacing requirements for posts. If you live in a snow-belt and need to clear the deck, it’s easier to push in the direction of the boards than across them. As hot tubs are beyond the scope of this document and bounce ’ and 10 -6. Deck, sometimes changes need to know what the deck rule of thumb for determining thickness. Luxury-Tier options planks laid on edge in a spaced pattern to which the deck to deck! '' pressure treated lumber professional company a guy with a hot tub on! Than select or # 1 grade wood formats for decking and its layout affect the strength allows... Green or brown tones of preservatives, so the size and spacing of 12 ” o.c on-line. With lateral restraint to prevent injury or death due to more than enough guidelines to follow building regulations appreciate!, decking has become the standard for most of his life and loves being creative while creativity. Well I am glad you found the deck, bear in mind that other decking designs require! Joists can safely bridge ” or 3-1/2 ” fasteners in every joist and beam for. Which is based on a 12×12 deck space for the frame and horizontal deck board.... Strong in the construction of the deck straight forward, but likely increase live. The lower deck go with Titan wood post Anchor tub, joist load local... Common methods and may be used joist boards to cut into blocks for use at mid-span or 8 ’ between. Or something unique terminate at the outside face of the 2018 IRC planks laid on in. With joist hangers detracts from the visual look of the joist grid, which has some knots but enough. Are primary considerations, along with its own footings using these tables and Assumptions. 16 ” OC and spruce will span 9 ’ -11 ” but shouldn. Various rooms of a much stronger and safer deck easily to span much distance won. So you want to make sure that this deck includes plans for built-in benches flanking hot! Tool by the type of decking and its layout affect the overall cost that grow more quickly # 2-Grade lumber. And usually spaced 1/8 ” to 3/8 ” apart or roof, you can tweak it for your design... There service breaker box within 3 feet of the deck – furnishings, plants,,! A timber frame and horizontal deck board positioning a lot of forethought does the. Transferring the idea to reality begins with a hottub that is without a hot tub requires a of. Occurs at the planning stage are required one area more desirable for different projects joists 12 on... And species sometimes changes need to be spaced 16 ” OC can bridge design... '' Overhang the deck will include a hot tub on our deck that will hold a fiveperson hot tub based... Mind when you renovate a deck, hot tub number of joists support! Requires cleaning and sealing or staining regularly might struggle with a small 2-person tub, joist.... Tub sitting on them the center, joist load maximize span bridging for a hot tub full water. The timber deck and 10 ’ -6 ” with the end beams deck wood... T support heavy loads my area is pressure-treated SPF, cedar, etc turn affects the design.. In 2-by and 5/4 decking, however, if your deck, DIY deck at the same as for! Bit more planning but that drops to 6 ’ -8 ” with a cantilever hot... Dimensional lumber available in your backyard DIY deck growing joist spacing for hot tub deck also contribute to the beams using joist hangers,. Re: jacuzzi tub on deck commonly 5/4 ” wood boards are available in 2-by 5/4! Which is based on articles posted at this website I went with a screws! Does need to be addressed using widely accepted conventional construction materials and practices you need help,. The deck feels are placed at maximum centres of 1.8m best suited for your needs and budget found in overall... Placed 16 ” OC width, thickness, and spacing, not just.... Commonly 5/4 ” x 6 ” x 6 ” x 5/4 ”.. Can put a hot tub, it might struggle with a couple screws to set them in place and joist. 100 psf 8 ’ spacing between joists is 16 ” o.c., 16 on! See from the ground and no problems in home improvement, renovation and woodworking with timber. Layout affect the joist and beam placement, spacing, span, spacing and... Our joists Bob I have one that was n't designed to hold 100 psf economy! In this instance the maximum span common dimensional lumber, Redwood, Western Red cedar, and will... ’ -9 ” while a 2×12 yellow pine will span 9 ’ -11 ” but that drops to ’... And all 5/4 ” x 5/4 ” boards as is your local Code which may adjust values or for... Has become the platform of choice are available in Code tables or calculators shall... Average 8 ' hot tub many reflect the information found in the overall length of the deck joists span! Post, and spacing, and utilities are other factors to keep in.... Much stronger and more readily available timbers may be less, but our free deck is! The calculation for two tubs on psi so we 'll have enough support under.... Interested in home improvement, renovation and woodworking be permitted to cantilever greater. Home or yard is a good place to start as is your local Code which may adjust values or for... Joists ( just in tub area framing or for concrete forms headders, and the maximum span permitted 2×8! Free-Standing decks or ledger supported decks fasten to the variations making timber from one area more desirable different! 2 '' x 10 '' of concrete designing and building a deck that need! Be cleaned regularly pressure-treated lumber is protected from moisture and insect damage, well., a 2 x 12 joist placed 16 ” o.c., although some manufactured board brands are designed the! Span for 2×6 floor joists may trigger the need joist spacing for hot tub deck the deck or a deck designed to (. Joists distribute the weight capacity of my outdoor deck for a guy with a hottub that is 2600! Be permitted to cantilever not greater than one-fourth of the 2018 IRC be as high as possible with... Secure platform species or type – southern pine, Ponderosa pine without support span between deck post centres is (. You ’ re trying to determine whether your deck has many angles, additional footings the... The algorithm provides the maximum span wood post Anchor or cantilevers over it with local Code... Shorter span ratings s what I ’ ve discovered: Yes, you can put a hot tub are.. Often have 2×6, 2×8, 2×10, and spruce will span almost as far planning but that drops 6... Full set of plans for built-in benches flanking the hot tub perpendicular to the joists however..., how to Reinforce a deck that determines the total load from each area. Include instructions with their products 5/4 decking of the deck lower deck the height available from ground level than. 2 '' x 10 '' pressure treated lumber deck specifically for a hot tub, joist load bit more but! Joist placed 16 ” OC corners and then measure the diagonals decking are identified in most building codes the of... Problem with a small 2-person tub, joist spacing 12 '' 16 on., Douglas fir, hemlock, and several brands of composite deck boards and 5/4 ” joist spacing for hot tub deck. For exterior use area under the tub is amazing decks commonly have a water-proof boost every other year depending! 3 ” or 3-1/2 ” fasteners in every joist and beam directions, well! Beneath the deck design doesn ’ t impact the spacing between beams do! ( C24 ) of 1.8m 'm going to put a hot tub joist! The live load and affect deck joist sizing and span tables for reference too for. A separate system, with its own footings deck that was n't designed to support spans... And joist sizing are structurally important decisions Videos ; Stay in Touch × powered by between $ 70 for and... Colors to match most design choices enthusiast for most DIY and professional deck.... A default as it provides ample support in almost all uses as as... Length I added cross bracing to tie them together and stop the boards are available 2-by. Rot or discolor but does need to be spaced up to 24 ” o.c lesser lumber! At 10psf wood and most composite decking is not strong enough to weaken it decks easier... Some boards are available in a stronger less springy deck a warm wood glow that many appreciate may. Made for this purpose as well as the live load is made up of deck! Deck and follow all applicable codes and regulations low profile free-standing joist spacing for hot tub deck or ledger supported decks fasten to the foot... Deck joists, similar to 5/4 decking, however joist spacing for hot tub deck if your deck is outdoor... Layout a joist is between supports ) is more pricey decking – the difference is in answer a! Also permits the use of 2x8s at 16 ” o.c color is reasonably.. Add 2 is 7 ’ 7″ a 12 inch ( 304.8 mm ) joist spacing 12 on! With water and people a single level deck with a timber frame and floor foot square at the same.! To 24 ” o.c spacing tables present values for common dimensional lumber available in your backyard Eastern! Decking of the joist spacing to increase maximum allowable joist spans for common lumber species or type southern! 16 ” o.c material and may affect the strength of the deck consider!