all floor joist tables start with 2x6 lumber. if you use awc calculator 2x4 can span 6'2' with l360 deflection for decks 40lb ll. i personally think it will be a bouncy floor. shorten the span maybe to 5' and put them 12' oc or like mac said 4'- 16' oc.
if using a standard size floor joist creates a problem with your finished floor elevation, look into notching the joist at the supports read your local building code for notching requirements . finally, if you can't get a standard size joist 2x6 or larger to work, you'll have to find a way to prove to your building department will accept 2x4's.
deck joist sizing and spacing. the layout term for joists is on center, which is the center-to-center measurement from one joist to the next. most decks use 16' on center spacing for joists. most decking is not strong enough to support longer spans than 16'. some builders reduce joist spacing to 12' on center to strengthen the deck
low profile deck using 2x4 joists by: editor - rich bergman 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.
the patio is not actually going to use beams, but i am going to dig several footings along the entire area of the deck in order to keep the patio as low as possible. the joists are going to be 2x4x8's. i am debating whether to attempt to span 4' with the 2x4's thus needing to put 3 footings per 2x4 or if i need to go with 4 footings per at 2 2/3 foot spans.
if you are allowed to use 2x4's for the joists, it'll cost you more money than using 2x6's would. the 2x4's won't span as far, so you would need more beams and more footings to support them. and your math on the beam spacing isn't adding up. 3 beams spaced 5' apart total 10'. add 2' of overhang on each side and that makes the deck 14', not
what is the safe spacing of 2×6 deck joists to support a 3500 dead load of a sp. the only time i even consider using 2×6 joists for a deck is if its 4x4 maximum.. bare minimum here is 2×8s for a standard deck. if were building one with a hot tub we automatcally go to 2×10s.
in general terms, joists spaced 16 inches on center can span 1.5 times in feet their depth in inches. a 2x8 up to 12 feet; 2x10 to 15 feet and 2x12 to 18 feet. the larger the deck, the larger the joists. 2x6 joists should only be used on ground-level decks that do not require, and will not provide for, any guards.
i have most of the wood already so i would like to build an attached deck 20 x 14. can i use 2 x8's for the 14' joists. i will have a 20' beam from 2 x 10's side by side with 4 x 6 posts at 4 in a row/4.5' apart from each other.
without seeing the exact plan for you deck it not possible to say with certainty. the wider deeper the joist the more load it can support with deflecting. in other words, when you put weight on the deck, the joist won't bend. the usual solution for dealing with undersized joists is to use more of them, spaced closer together.
if you use 5/4 decking, joists must be no farther apart than 16 inches. decking made of 2x4s or 2x6s can span up to 24 inches. if you will run decking at an angle, you may need to put the joists closer together; know your local codes. how to compute the spans for a deck tell us what you think submit. thanks for adding your feedback. shop
2 x 4 for floating deck using deck block possible? by al but i would tell you that using 2x4s as joist is problematic. they are much weaker than 2x6s so you will have to have a much tighter joist spacing, certainly no more than 12' from center to center. in fact you may have to have a block every 2-3' under each 2x4 to get rid of any
the reason im asking is that a 6x2 ledger board would put the deck a little higher than id like at the post end, and im trying to avoid having to put an intermediate step down onto the grass. cost is an issue too as there will be around 100m of joists in total if i use 400mm centres and 2 rows of noggins. cheers
if i had used 2x8 or larger joists instead, i could have, for example, pulled a solution right out of the prescriptive residential wood deck construction guide: based on the 2009 international residential code, which is a free download from the american wood council at awc.org. but the guide doesnt even mention 2x6s in its joist-span tables.
protect your deck from joist rot. family handyman. a little diligence and an inexpensive deck flashing tape keep things protected and help prevent deck joist rot. last summer, i helped a carpenter buddy tear out a rotten deck. the joists were pressure-treated lumber, so i was surprised at how badly decayed they were. but my friend wasnt.
which is better for deck flooring: 2x6 or 1x6 deck boards? ask question asked 8 years, 6 months ago. active 11 months ago. using 2x stock over undersized joists does help make the deck feel more solid. if you have 24 oc joists, i'd definitely stay with the 2x decking. an other option if you have wider joist spacing is to add a joist between
codes typically call for attaching joists with joist hangers at the ledger. they are sometimes not required at the header if they rest on a nearby drop beam and you drive nails through the face of the header into the joists. but even in that situation, some inspectors will want to see joist hangers.