Cable Railing

[amjay]

I am dealing with an existing home with deck and railing built in 1987 when I believe the UBC was in effect in California. If no structural changes are made to the exterior decking, support posts, the railing support posts and the existing top railing is not modified but cable railings are installed in lieu of the current wood pickets should the current CBC be applied requiring that the top rail to be raised from 36" to 42"?

 

[steveray]

I would say no, but I am not from California...Welcome to THE forum!

 

[tmurray]

Personally, I would say no. The hazard created from the lower than permitted guard is unrelated to the material used as infill in the guards.

If the whole guard structure is being replaced, I would say yes it must comply.

 

[ICE]

I would not require the guard to be raised if only a component is being replaced. Here is a recent picture of a cable system at a California State Park. Cable systems require maintenance. The tension that's applied to the cable is substantial.




There might come a time when there's not enough adjustment left to take up the slack.

 

[SCBO1]

Curious if that cable system save the CA State Park any money vs 2x4's?

I would think that set-up would never meet code no matter how many times Yogi's Park Ranger Smith's goes out to adjust!

 

[ICE]

Curious if that cable system save the CA State Park any money vs 2x4's?

I would think that set-up would never meet code no matter how many times Yogi's Park Ranger Smith's goes out to adjust!

The cable and hardware are more expensive than the lumber this would have required. The amount of labor is much greater.

The cable system might have been code compliant for a day or two.

1015.4 Opening limitations. Required guards shall not have openings that allow passage of a sphere 4 inches in diameter from the walking surface to the required guard height.

 

[tbz]

The issue is not with the cable stretching, it's the wood's shrinkage.

The connectors shown if installed properly will never fully travel the full tensioning distance they are designed for if the projects frame was designed and installed per the limits of the manufacture's specs, which most of the time on wood frames they are not done. So not the cable's fault.

Some key points and these have been disgusted at length on this forum over the last12 plus years.

• Industry standard Maximum of 50-foot run between tensioning posts
• depending on the cable size, looks like 3/16" or 1/4", 1x19, 36"-42", some outliers 48" between verticals stabilizers or posts
• for 3/16" or 1/4" cables, 3.125" - 3.3125" centerlines on the holes
  • 3" centerline is for 1/8" cables.

IBC 1015.4 is not a load test, it's a measurement dimension for the 4-inch sphere.

If installed properly as noted above, on a frame built for the tension correctly, you could apply the Infill load spread test in the prior version of ASTM 935 with the 50lbs on the non-code adopted decades old test parameters using the 50lbs specific for the other and only infill code load for the 12-inch square area and pass.

But infill spread via the cone test or sphere load is not in the codes, just take a look at the results of this past code cycle.

 

[mark handler]

I am dealing with an existing home with deck and railing built in 1987 when I believe the UBC was in effect in California. If no structural changes are made to the exterior decking, support posts, the railing support posts and the existing top railing is not modified but cable railings are installed in lieu of the current wood pickets should the current CBC be applied requiring that the top rail to be raised from 36" to 42"?

Their insurance company MAY ask that it be raised, but the code does not require it to be retroactively raised.
I May, depending on what is being done to the deck, require it but we do not have the full picture/information.

 

[Yankee Chronicler]

Considering the tensile forces needed to keep the cables tight, I SERIOUSLY doubt that even new wood posts on an all wood deck structure are up to the task. I would almost guarantee that posts and a deck that have been in place for 36 years aren't adequate.

 

[bill1952]

I wonder if there are any documented incidents of a cable rail failing to prevent someone from falling, not that efficacy should be considered in codes.

 

[ICE]

not that efficacy should be considered in codes.

Efficacy should be an important consideration of the codes but there is no mechanism built in to codes for that. While it is assumed that what is built is built to last… that is not often expressly evident in the text of the code.

There is a shortcoming in the NRTL evaluation process. Products come to us with UL, ETL, CSA, ICC-ES, IAPMO, Etc, Listing and we usually approve the product based on that Listing.

 

[Mr. Inspector]

I installed this cable system on my deck. I did not put a board between the posts near their top just nailed a 2x6 on top of the posts. The cables were loose the next day.

 

[Inspector Gadget]

I will add this to the conversation:

I have only approved one (1) cable guard installation outright. Almost every single one deflects too much (ie: allows passage of an object larger than acceptable).
Of the many - I'm guessing eight-ten- that have failed initial inspections, only one (1) has subsequently passed re-inspection without significant alterations. In one case, the client gave up and installed glass.

The only one that passed on first inspection had a cable spacing that was 3" and was massively overbuilt.

 

[tbz]

I installed this cable system on my deck. I did not put a board between the posts near their top just nailed a 2x6 on top of the posts. The cables were loose the next day.

Rick,

Wood frames are the worst for installing cable infill by far. You need a strong end post and then non- shrinkage to hold.

A few examples of installations that passed ASTM E935 Cone Test of 50lbs, though not in the code as a requirement.

 

[Robert]

The system I have used actually states to install the cables 3" o.c. to address the deflecton issue. Also, there are vertical cable systems that deter kids from climbing. Don't write off cable systems....they allow view and don't have wind loads to deal with like glass.

 

[SCBO1]

Nice pics tbz!