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While you are at it, (not using plywood) Forget the PT as decking unless you are going to eventually put a finish of some kind on it after it has seasoned. That PT opens up like a mutha– checks, twists, cracks etc. It only takes a couple-three seasons to wreck it. Use Fir or similar finishing 6 sides before they go down. This will seal it up and keep moisture from getting in from under. Once installed do your 2nd coat of stain or clear.
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I building a deck and have a question about the beam that I'm bolting to the posts. I'm using 4"x4" Posts with (2) 2"x8" bolted to each side of the post. How do I "Splice" the beams if the total span is 26', Posts Approx 6' C-C and I'm working with 16' 2"x8". I'm going to stagger the joints, but do I make the joint at or between the posts.
*At.
*b TVMDCi How do I splice the beams?You don't. What would be helpful is to know the full size of the deck: is it 26x12 or 26 x 32? or what?Normally, the floor joists run the short dimension in a deck unless you have a beam at mid span and use joist-hangers on the beam.A little more information would go a long way to solving your problem.
*16x26 16' Joists, 26' along the length of house. I'm bolting 2x8" to house with Joist Hangers 16" O.C. I'm construction 2 beams bolted to posts at 8' & 15' from house where the joist will rest on.Is this helpful?
*Ex,Break em at the post. However, I don't think you've got enough meat left at the splice to bolt it through the post. I would think about either sitting them on the 4x4 or solid block on the 4x4 below the spliced beam. Bolts in the last 1 1/2" aren't the strongest joint in the world. Up to you. Best of luck.
*If you haven't built it yet, use 2 x 10 instead of 2 x 8. At any rate, the beam "splice" should be at a post.Red dog
*I'm in the process of building my own deck as well in N.Y. I'm using 6x6 posts that are haunched to accept a 2x10 on either side, and then through bolted. My deck is 8" of the ground, that's why such heavy timbers. As stated above, put the joints on the beams.Good luck!!
*b TVMDC2x8x16 floor joists suspended from hangers on a 2x8 ledger are fine. As I understand what you said, you have a row of 4x4 posts 8' and 15' out from the wall. On the middle row of posts, cut them 7.5" below the bottom of the underside of the joists and run a 4x8 beam parallel to your ledger. The posts are then cripple posts and can be connected to the beam with a simpson PC44 (Post Cap). You can easily splice the beam in the middle of the PC44 since its "L2" (i.e., the length of the lateral side flanges...see a simpson catalogue) is 11" allowing for bolts and nails in each beam end.The same applies to the row of posts 15' out from the wall except that here you can either replicate what you did on the middle row or bring the outer beam back up to the same level as the ledger and use hangers.2x8x16' joists with a mid support beams cuts the span to only 7 or 8' which is ok. And with the mid support, you will have a more solid deck than 2x10 joists with no mid support.Good luck!
*Carolina man, I am assuming that you will be using 16' 2x8's for the beams also. Also the spacing of the posts is 8' apart. If this is true, one length will be able to span the distance between two posts, or span across three posts. That means that you will only need one splice per post. One should always try to divide the splices up evenly. If you notch a post 1 1/2"x7 1/4", that leaves 2" of post to bolt to. This is much better than 1/2", which you would have if you set both beams on top of a 3 1/2" post. On the first post, notch for the 16 footer, and lag the 8 footer to the remaining 2 inches. The next post will be staggered 1 1/2" towards the 8 foot peice, and will be notched for the 8' peice to set on. This way, the splices have 1 3/4" solid bearing, and the continous peice can be lagged to the 2" left on the 4x4. The next post will be staggered back 1 1/2". You should use 2x4 blocking ripped to 2", just like 1/2" plywood in a header, but when installing the blocking, cant the peice at about a 15 degree angle. THis will engourage water to run off the block. I hope this makes sense.Jon Blakemore
*I missed that detail of "posts at 8' and 15' from house". 2 x 8 joist are fine as Bill stated. I always put the beams on top of the posts, as Calvin recomended. I like the direct support, but see a lot of guys bolting to the side.Red dog
*I'm with Cal and Dog. Beams oni top of posts. If you don't want to buy the Simpson brackets Cal suggests, you can scab ~30" 2x4s on 2 sides of the post & beam to hold the beam in alignment on top of the post. Use a piece of ½" PT plywood to space the beam and make it 3 ½" wide (the width of the 4x4 posts).If you must bolt, step up to 4x6 posts, and then a 2x8 can be let into each side of the post. Still, I don't like the space between the 2 beam members.A basic concept of building: Whenever possible, b members should be stacked on top of one another. The fasteners merely hold the members in alignment. One acceptable exception is joist hangers - I'm sure there are others.
*Thanks BillI went to the Simpson web site and saw the PC44 that you talked about and that makes sense. One question. When I space the two 2x8 beams with plywood to make 3 1/2". I assume that I should use pressure treated plywood.
*b TVMDCI would recommend using a 4x8 beam which will marry perfectly to the PC44 and the 4x4 cripple post. However, if you already have the 2x8's, see sisitering joists for laminating tips.But I would not use plywood shims, even CDX: you have only 1/2" to make up: why not use two Simpson BP 5/8's to fill up the gap. You could center them on the either side of the wood on the bolts.FYI, attached is a photo of the PC44 for those unfamiliar with this hardware.
*Matt,Not challenging, just learning. This has been an informative thread.Why don't you like the space between beams. If spacer blocks were used between the beams/between posts would that be ok?
*Herb:Yea, spacers would be OK. But let me ask you this. Which would strongest - 2 2x8s with gap between, or 2 2x8s with a solid spacer (or no spacer) and about 20 10p nails joining them together into, effectively, one unit? It's kinda the same as the way plywood works. This is especially true when you are building a beam that is longer than the material you have (like in ExNYer's case). That's my thinking anyway.
*DON'T USE PLYWOOD! You'll only trap water inside the beam. Rip yourself some 1/2" strips from a 2x PT and use them for vertical spacers 16"o.c. Place them at a slight slope so they drain off the end grain.By the way, thanx for not moving to Georgia. We got too many customers already.
*While you are at it, (not using plywood) Forget the PT as decking unless you are going to eventually put a finish of some kind on it after it has seasoned. That PT opens up like a mutha-- checks, twists, cracks etc. It only takes a couple-three seasons to wreck it. Use Fir or similar finishing 6 sides before they go down. This will seal it up and keep moisture from getting in from under. Once installed do your 2nd coat of stain or clear.
*BG 71, We are so used to making everything level, plumb, square,etc. I just built a deck on my own house, and DID NOT cut the tops of the ply wood on an angle,I made them level- dumb. Thanks for the great tip, You learn something new every day, and if you don't, get out of the business!!!Thanks again!!
*Cutting the spacers at an angle sounds like a reasonable approach. I think I'll adopt that one.Jim:So, your saying that fir with a stain on it will last longer/weather better that PT SYP with a similar finish on it? Interesting!
*Take back the 2x8's and get 4x10 incised pressure treated beams. canter lever 2' off each end making your span 12' to the center post. 3 posts 2 beams and 6- 2x4 gussets will give you better strength and appearance. Don't forget to canter lever your floor joist's approximately 2' as eel. Good luck