Discussion in 'Framing and Foundation' started by RockyMtnBlue, Feb 26, 2012.
Do I need to use mending plates?
I will attach the two beams with two 1/2 bolts (a total of 4 bolts). Do I also need mending plates?
No the bolts are plenty.
Maybe a little construction adhesive if you have an open tube, on the ends of of the 2ply beams where they will meet. Will help keep the entire joint water tight. A few screws with the glue will eliminate the need for bolts
Thanks... No mending plates and construction adhesive.
Sorry, but I would keep the bolts. Screws have no shear strength and can snap under load. I know it's easier, just no where near as good.
Oh yes, did not mean to imply that I won't be using bolts.... Bolts and construction adhesive, no mending plates.
Bolts will bring you up to minimum Code, as will post bases; http://www.awc.org/Publications/DCA/DCA6/DCA6-09.pdf Use some Grace I&W shield on the post bearing area, p.t. wood is not waterproof: http://www.greenbuildingadvisor.com...ressure-treated-sill-plates-and-building-code
You need stand-off post bases for the capillary break they provide. Nails, not screws, for the sistering- as said. Use the I&W on the built-up beams top under the joists above for less water intrusion, or at least a bead of caulk- top only to drain below. Run a bead under the outside edge of the house ledger for a drip edge to stop water from working back to the house.
Well-spoken, Gary. And if it were mine, there'd be a sistered PT vertical 2 x 4 on the back of every chopped up support post, extending below the break point. Just to minimize the damage when the little lady of the household smacks the deck with the garden tractor at full speed.
Thanks for the feedback ... I'm learning something for every post. Question about my beams.. I'm attaching (sistering?) two 2x10s. The book says screws about 24" apart. From comments here, I gather that I should use construction adhesive and nails. I read that I should use 3 nails every 16". Comments?
Ledgers: ok to bolt ledges directly to concrete? Should I fill the gap between the concrete and the ledger? Silicone chalk?
Securing posts to piers:
I plan to use concrete expansion bolts and angle brackets with a single 1/2" bolt. Comments?
The beams will be secured to the posts with two 1/2 bolts in each beam.
You don't need chaulk or anything between concrete and treated wood and your bolt down is fine.
Sounds good to me, However there is One last thing I would add. I would seal all cuts I make with a waterproof sealer such as anchorseal. Most of the PT wood is fine, but sometimes the preservative doe s not make it all the way through the new PT.
Have fun, and post pics when yer done!
If it were mine, I wouldn't try to attach the spliced beam ends to the 4 x 4 posts with 4 bolts. What you're proposing doesn't leave enough "meat" between the edges of holes and ends of members, and actually creates weak points at both the beam ends and the back-side 4 x 4 posts. Wouldn't be an issue if you had used 6 x 6 posts, as the IRC requires. A much stronger connection for your situation would be to use 6 through-bolts, 2 longest drilled into the gap between beam ends (with mender plates), and also going through a centered rim scab on the outside; the other 4 shorter ones could then be located farther away from the beam ends, going through them and the outside scab, but not connected to the vertical post. Posts and beam ends would be much stronger doing it that way, and wouldn't be likely to fail when you load the deck with 15 tons of people.
BridgeMan, a 6x6 is possible, but I don't know what a "rim scab" is...
Is this an acceptable alternative? Or another 4x6 sistered with 1/2" through bolts, since I already have additional 4x6s.
Disregard (can't figure out how to delete a post from iPhone app..)
Code requires 6x6 or have your local inspector pass the 4x4's as they are so short, see the "notes" at the end of this Code Book: http://www.awc.org/Publications/DCA/DCA6/DCA6-09.pdf
Two bolts on each end of beams are required on a bearing post, notice the picture and placement Tables.
Concrete is a porous material that stores/wicks moisture and water like a sponge. Capillary action will wet the wood if drier than the porch concrete---- pressure treated or not, and soon start rot.The pressure treatment is against bugs and decay rot, not water. As said, treat the p.t. with a water-proof, the whole thing. I would use some Grace I&W shield on the side against the concrete and install it on stand-off washers for water drainage.
Screws are not acceptable other than on decking unless rated special as Simpson hangers/etc. Nails are called out on the Deck Code link stated. As are bolt placements, spans, piers, stairs, treads, risers, handrails, etc. It would answer any questions you may have though you need to read it first. Nice picture contrast and placement, BTW.
Gary and other, thanks for the feedback. My first project this big. I used the online deck planner from Lowes and I guess I expected more from the city permit process when I turned in my plans. After getting city "approval", I discovered the AFPA doc you have referenced and have adopted many of those standards... With a few exceptions. Up until now, I've been thinking that since the city accepted my plans and all the decks I see built all around my area within the last year or two are 4x4 posts and 2x6 framing that my plan met their standards and the AFPA was a stricter standard. Thus, I have been thinking that my post size 4x6 is better than what my plan calls for (4x4) and what I see on decks just built on new houses.
Now, I'm thinking that I better check with the inspector before going any further. I'll be doing that Monday.
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