# How to use Simpson Hold downs for gaurd rails



## Termite (Apr 13, 2008)

Omission of the joist hanger would not be a good idea. Personally, I would not approve the hold-down in lieu of the hanger. :no: It would probably never be an issue but as an inspector I wouldn't hang my name on it without some engineering support.

I'm not very impressed with the idea of securing a guardrail with hold-downs. Seems like Simpson just finding another way to sell products, and I don't see this method being all that effective at all. Solid wood blocking would be much, much more effective at reducing or eliminating movement of the newell posts.


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## Willie T (Jan 29, 2009)

thekctermite said:


> Omission of the joist hanger would not be a good idea. Personally, I would not approve the hold-down in lieu of the hanger. :no: It would probably never be an issue but as an inspector I wouldn't hang my name on it without some engineering support.
> 
> I'm not very impressed with the idea of securing a guardrail with hold-downs. *Seems like Simpson just finding another way to sell products*, and I don't see this method being all that effective at all. Solid wood blocking would be much, much more effective at reducing or eliminating movement of the newell posts.


:whistling2: I was biting my tongue, trying NOT to post that thought.


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## Scuba_Dave (Jan 16, 2009)

Is this required for any sort of Earthquake "code" in your area?
The one on the left is just a piece of blocking
Based on the view of the item I'd say the hanger can also be installed


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## rocketdoctor (Mar 18, 2009)

No specific codes Im trying to follow. Im just trying to find out how to attach 4X4s to the Rim Joist and Beam. There was an AWC and Simpsons document recommened to me that I was following. Is there any suggestions for attaching posts. Ideally I would like them sitting on top of the beam and rim Joist so I can put the decking around


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## Willie T (Jan 29, 2009)

First question.......... How far along are you at this point?


BTW, Simpson says: "Tested within the limits prescribed by ICC’s Acceptance
Criteria for Handrails and Guards (AC273) _*and for Joist*_​*Hangers and Similar Devices* (AC13)."


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## rocketdoctor (Mar 18, 2009)

I have my deck planned and most of my materials ordered, was planning on installing metal gaurd rails but starting to realize I can't afford that (after ordering all the wood) so I decided to use wood posts and 2X2s.


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## metlc (Aug 11, 2009)

Simpson is somewhat ambiguous on this.

I'm using the HDA2s now at the ledger for lateral retention as recommended by Simpson's "pending new code" pitch, but with those two little stamped ribs on the bottom they seem to want some plywood shims (at the ledger and on the joist) to seat properly over the joist hanger nails. 

If you look at Simpson's Deck pdf bulletin page 9 (here) a few pages before the one you're quoting, it shows an installation with their DKT22 hold-down installed along with joist hangers. The DKT22 is installed in an offset manner to give clearance to the hangers. The same would presumably apply to the HDA2 hold-downs. 

I also recall seeing somewhere in the Simpson catalogs that the HDA2 (and other) bolted hold-downs could/should be installed in an offset (raised) manner on 2x studs/joists to increase their hold-down force rating. With that in mind, and not wanting that extra wood/ledger joint to just rot out, I'm going back and remove the plywood shims and just leave the hold-downs sitting 3/4" off the ledger. The same applies to the deck rim joist connections.


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## Willie T (Jan 29, 2009)

Bring all your railing support posts right on up from way down on the foundation as solid, full length posts, and you will eliminate the need for any additional lateral support.

Ever wonder what Simpson's costs are in lobbying and "other incentives" that may have been paid out to various construction agency employees over the years?


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## metlc (Aug 11, 2009)

I don't see anything wrong with adding in another $15 worth of bolted connectors to connect the edge of the deck with the house framing. More than that in labor, I guess.

And you can't expect that running ground-level support posts up through the decking will provide for all of the guardrail posts you may need.

I can also see the wisdom in anchoring the deck-level railing posts to the deck joists, which are better oriented to resist the leverage of the guardrail posts than the rim joist is. The deck joist is in tension/compression. The rimjoist's resistance is in torsion, however transient that load is. Either of those methods, though, seem stronger than any of the post surface-mount systems I've seen that seem to be all the rage now. I guess it's all a tradeoff for joint exposure/rot versus strength.


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## Willie T (Jan 29, 2009)

metlc said:


> I don't see anything wrong with adding in another $15 worth of bolted connectors to connect the edge of the deck with the house framing. More than that in labor, I guess.
> 
> *And you can't expect that running ground-level support posts up through the decking will provide for all of the guardrail posts you may need.*
> 
> I can also see the wisdom in anchoring the deck-level railing posts to the deck joists, which are better oriented to resist the leverage of the guardrail posts than the rim joist is. The deck joist is in tension/compression. The rimjoist's resistance is in torsion, however transient that load is. Either of those methods, though, seem stronger than any of the post surface-mount systems I've seen that seem to be all the rage now. I guess it's all a tradeoff for joint exposure/rot versus strength.


Perhaps not "all", merely 100%.


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## metlc (Aug 11, 2009)

I've got a 13-foot span between the main support posts. I guess I could have put another support post halfway between. Downstairs below, though, it wouldn't look as good, gazing out through (and having to walk around) that extra post.


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## rocketdoctor (Mar 18, 2009)

metl2c thanks for pointing out the illustration on the other simpson document, I think I'll go with the dtt2z. Im not crazy about running posts to ground I would have to pour a bunch more foundations. I just found out that I can't even get IPE 4X4's so this is a temporary solution until I can afford Metal railings to replace.


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## Termite (Apr 13, 2008)

Do yourself a favor and forget about using metal products to secure your railings. Nothing will be more rigid than blocking between your posts and rim joists with 2x dimension lumber the depth of the joists. Draw everything tight with bolted connections. Rock solid...No fuss. 

Trying this with metal brackets that aren't intended for the purpose is a futile waste of time. That's coming from somebody that has built hundreds of decks and inspected thousands of them. 

Full height posts are great when they can be used but solid blocking will make the railing newels nice and solid.


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## drtbk4ever (Dec 29, 2008)

rocketdoctor said:


> I just found out that I can't even get IPE 4X4's so this is a temporary solution until I can afford Metal railings to replace.


What do you mean you can't get 4X4 Ipe posts? 

This place seems to have 4X4 and 6X6 posts. 

http://www.ipedepot.com/picelist01.htm

So they are available. Affordability may be another issue altogether.


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## Termite (Apr 13, 2008)

Tigerwood (goncalo-alves) can also be stained to look just like ipe...They're in the same species group.


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## rocketdoctor (Mar 18, 2009)

Lots of good advice and I spoke to soon about 4X4 IPE just couldn't get it from where all my other materials are coming from. Is there away to attach the 4X4 guardrail post directly above a 4X4 beam, could I use a post connector and then trim around the base to hide any exposed metal? My plans have a beam in line with existing overhead posts that I am trying to keep the gaurdrail in line with.


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## Termite (Apr 13, 2008)

No, you can't surface mount a post...Not if you want it sturdy. :no: 

You can notch the post and bolt it to your deck's rim joist. Nice and sturdy. You can install it before or after you lay your decking. It often helps to attach blocks to the post after installation to give you a good attachment point for your decking so it has its ends secured by the post. That helps stiffen the post as well. Once again, a good place for solid blocking between the joists to stiffen things up!


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## metlc (Aug 11, 2009)

rocketdoctor said:


> metl2c thanks for pointing out the illustration on the other simpson document, I think I'll go with the dtt2z.


"Upon further review" of your original Simpson detail drawings, a few more sleights-of-hand are revealed by a discerning CSI examiner.

The drawings on Page 9 mentioned earlier show two details. The second one, "Deck to Ledger Installation, Section View" shows the DTT2Z installed _above_ the joist hanger. However, the first one, "Deck to Ledger Installation Detail," shows the DTT2Z fastened _over _the joist hanger. Because of the short (13/16") centerline offset of the DTT2Z which would interfere with the joist hanger ears, this is accomplished using a different (turned-in) hanger than is shown in the Section View.

I imagine that the old-school builders might pooh-pooh the new 2x turned-in hangers. Certainly not as strong as the conventional ones. They sure look tidy, though.


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## swooby (May 11, 2010)

I found this thread while also scratching my head over the same problem.

I have emailed Simpson about this, and sent them this diagram:









If you take out any obstructing nails and drill out two holes for the post bolts, once the bolts are tightened the final assembled solution would not seem to violate code or weaken the joist hanger connection.
The offset of the DTT2 in my diagram is a bit exaggerated, and one might argue that it isn't required.
Still, I am a bit disappointed both in that a more-real-world application diagram is not given and that the two brackets don't interlock any better (thus requiring questionably drilling two 1/2" holes through one side the joist hanger).

In addition to the interfering joist hanger, I also have an issue w/ a non-right angle rim. Taking their blocking example as a guide, what is the correct way for a DTT2 to be tied to a joist from a non-right-angle rim?


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## xxPaulCPxx (Dec 2, 2006)

It looks like the use of the hold down with the 5/8" bolt replaces the joist hanger, and that would make sense. 

The bolt is going to have alot more shear strength than the joist hanger.


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## rocketdoctor (Mar 18, 2009)

xxPaulCPxx said:


> It looks like the use of the hold down with the 5/8" bolt replaces the joist hanger, and that would make sense.
> 
> The bolt is going to have alot more shear strength than the joist hanger.


I don't think its wise to sacrifice the integrety of the joist hanger. the hanger is meant to keep the joist set when the joist is under load from the top, The DT22 won't replace that support. I ended up doing was offseting the post so the Threaded rod just cleared the joist hanger. I used a long threaded rod and put it at a very slight angle so it clears the Joist but fits in the DT22.

for the right angle applications I just toenailed a blocking piece between the rim and joist. this was easiy since I first drilled my holes through guard rail and rim, then attached threaded rod to DT22 then i lined up the blocking toenails it and bolted DT22 to it and tighted up the bolts. Since the blocking piece is just meant to support the DT22 and no load above I didn't see need for joist hangers here.

Just my opinion Im not a licenced structural engineer or professional contractor (however I did get a mechanical enginnering degree 20 years ago )


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## xxPaulCPxx (Dec 2, 2006)

I'm saying the hold down would replace the joist hanger entirely. It may seem odd holding the load offset like that, but that is a minimal force that can be easily overcome with simple blocking.


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