Any way these rail guards are able to support 50lbs? The two stringers are 1x4’s with a 1x1 blocking in the center. This was done to the top and bottom stringers. You can see with one of the photos, I was able to push it out when the blocking was actually missing. I am going to put it in the report, but was curious if this is acceptable as a standard.
Also, anybody know what the longest span of a 4x12 is?
Thanks in advance.
Jeff
Jeff , do you have any pictures of the underside to show joists ?
Trying to figure if that is a cantilevered or if you have a ledger.
Not sure of the rim joist on a span chart off hand .
I swear it looks as if I see a downspout going through one of the supports underneath.
Jeff,
I don’t have time right now, but will check back later tonight. Check here for answers to your questions… http://www.awc.org/Publications/DCA/DCA6/DCA6-09.pdf
Jeff
Hey Jeff…
I was looking at the Deck Construction Guide before I posted and I saw the example that they had for the guard rails. Since this was an example, I was just wondering if anyone else had seen the setup that I encountered for the rails involving the blocks. The 4x12 span chart only noted down to a joist length of 6ft, where the joist length I saw was at 5ft. I’m still thinking that a 20ft span is too much. Thanks for your input.
Bob…
Yeah, that is a ledger that’s run along the building - including where the cantilever is. It’s going to be noted. Thing is… if everything was passed by Mr AHJ, there’s a whole subdivision of these 2nd level decks that have been installed incorrectly.
I gotta look out for my younger client, who will most likely have a group of friends over for her moving in party out on that deck.
Jeff
Jeff,
I think you will find this interesting reading. http://forums.jlconline.com/forums/showthread.php?t=53062
Although the thread was started for a different question/reason, there is a lot of info relavent to your situation.
Hope it helps.
PS… looking at other span charts, depending on species and load, the max. I see for the beam is 7ft. And no, I have never seen the guardrail set-up you have. I would suppose it would be okay **if **the upper and lower rails were attached to the posts with hardware/brackets, not just toenailed, which as you can see, doesn’t work.
Jeff
Jeff…
Thanks again for the input. Quit giving me these links to read up on…I have to finish my report! 
Started reading some of the attached articles and unfortunately being in the Chicago area, we are only too familiar with deck tragedies.
Jeff
Wish I could help more but it does not seem to be a true cantilever with those side supports.
Would like to find some info on that style but had no luck when searching.
I am also curious just how much support they are giving and what is on the other side of the garage.
Sure would be nice to see blueprints on something like that.
It is cantilevered. If you look at the first pic from the first post, you can see the door entry is bumped out approximately 3 feet. The thumbnail below shows underneath the deck. You can see where the aluminum soffit is. That is where the bump out is located. The 2nd thumbnail shows how it should have been constructed.
Jeff
Trying to help you search right now and there is lots on Guardrail post to rim joist connections but not much on handrail to guardrail post connections other than the obvious 200 lb pull requirement.
Sure looks bad with those nails going into the block like that.
Seems to me they would split the wood.
That’s the thing… they were at least careful enough to toenail into the guard post and not into the 1x1 blocking. So if that blocking is secured properly with 8P nails and there’s no splitting, the guard rail’s not going anywhere. The AHJ would’ve tested the force weight, right?:roll: Just wish the building office wasn’t closed until monday.
Jeff
Considering some of the porches I see in the city i would not depend on the AHJ to have caught anything.
I suppose it looks strong enough but wish I could find an example somewhere.
Normally they would toenail it in from both sides of a single rail of course.
As it pertains to the span of lumber it does depend upon the species of lumber, grade and the demension on center to the next joist. Look on the side of the lumber for any infor., it is proberly worn off.
You have identfied a major safety concern, as always u know to inform customer to call in ???
God keep us safe
Bill
Jeff
Judging from the picture that looks to be fairly new construction and if that is the case the designer of record would have to have approved the gaurd rail design. Even though I’m surprised a designer would just use toe nails. I would say the problem is more of a workmanship issue. The basic code articles require that (1)the top of the railing be no less than 42" above the deck (2) handrail and assemblies and gaurds shall be able to resist a single concentrated load of 200 lbs. applied in any direction at any point along the top, and have attachment devices and supporting structure to transfer this load to appropriate structural elements of the building (3) intermediate rails, balusters, and panel fillers shall be designed to withstand a horizontally applied normal load of 50 lbs on an area equal to 1 square foot (4) open gaurds shall have balusters or ornamental patterns such that a 4" diameter sphere cannot pass any opening up to a height of 34". From a height of 34" to 42" above the adjacent walking surface a 8" sphere shall not pass.
As far as span the ICC does not have published in the current code span tables for a 4x12. For point of referance here in Florida the most common species of lumber used on exterior decks is #2 preasure treated pine. A single 2x12 spaced 16" o.c. can span 18’-10" at 40 40psf
Note the blue highlight 34"- 42". I learned that the hard way after calling out the 4" sphere clause on a home that had a decorative railing where the top 6" of the railing was wider than 4". I had to eat my humble pie
The maximum 10’ header span shown on the diagram conflicts with the IRC maximum 6’ span.
