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Welmoed Sisson
03-17-2012, 06:45 AM
Just got a call from a home buyer asking about wire deck rails (the kind with horizontal wires under tension, rather than vertical stiles). He was wondering whether his county (Ann Arundel, MD) had a code for what the minimum wire size should be. My first response to him was that such railings are not considered safe, and he said he knew that, but still wanted to know what the minimum wire size was. Any ideas? Bob isn't in the office today so I can't ask him.

John Arnold
03-17-2012, 06:55 AM
...minimum wire size ...

Depends. 20 amp or 15 amp?

Sorry. Couldn't help it.

John Kogel
03-17-2012, 08:26 AM
John is right. There is no intelligent answer to that question. Tell the idjit to picture one of his kids or grandkids with his head stuck through there. :confused:

H.G. Watson, Sr.
03-17-2012, 08:52 AM
W.S.

"Wire" isn't used, specialized cable assemblies with threaded terminals or turnbuckles for adjusting tension (cable stretches) are for such architectural railings, etc.

This is NOT a DIY project (neither: specifying, designing & engineering safe systems/assemblies for particular applications; nor the safe installation of same - tools, crimping, testing, verification to spec. adjustments to same, etc.).

Strongly recommend that you refer the inquirer to a registered/licensed design professional.

Billy Stephens
03-17-2012, 09:50 AM
Just got a call from a home buyer asking about wire deck rails (the kind with horizontal wires under tension, rather than vertical stiles). He was wondering whether his county (Ann Arundel, MD) had a code for what the minimum wire size should be. My first response to him was that such railings are not considered safe, and he said he knew that, but still wanted to know what the minimum wire size was. Any ideas? Bob isn't in the office today so I can't ask him.
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Older Thread on this Subject. http://www.inspectionnews.net/home_inspection/exterior-systems-home-inspection-commercial-inspection/9645-jungle-gym.html
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Jerry Peck
03-17-2012, 02:09 PM
Just got a call from a home buyer asking about wire deck rails (the kind with horizontal wires under tension, rather than vertical stiles). He was wondering whether his county (Ann Arundel, MD) had a code for what the minimum wire size should be.

I would say the minimum size would be that which one cable would fill the entire guard rail opening from top to bottom ... that also eliminates the ladder they would otherwise be constructing ...

Michael Thomas
03-18-2012, 02:01 AM
I don't know that there is a "correct" answer to the OP's question.

The most common answer from manufacturers is usually something like:


The most common and cost effective cables for residential and commercial uses are 1/8" and 3/16" respectively. Cable with a 1x19 construction is most suitable due to its stiffness and resistance to stretching. However, we will occasionally do 3/16” cable in a 7x7 construction which provides a unique look. All of our cable is made out of 316 marine grade stainless steel.

- Cable Railings Technical Notes | American Metal Specialties (http://cablerailings.com/technical-cable-information.html)

Eric Barker
03-18-2012, 06:08 AM
Just got a call from a home buyer asking about wire deck rails (the kind with horizontal wires under tension, rather than vertical stiles). He was wondering whether his county (Ann Arundel, MD) had a code for what the minimum wire size should be. My first response to him was that such railings are not considered safe, and he said he knew that, but still wanted to know what the minimum wire size was. Any ideas? Bob isn't in the office today so I can't ask him.

I'd tell the buyer that I couldn't answer that question as I don't approve of horizontal guards in the first place - as Jerry said, kids can climb to the top of the railing. Even if the AHJ had such an allowance I'd still be calling it out in my reports as a safety concern. Giving people any advice on how to do something wrong seems like a real liability issue.

Scott Patterson
03-18-2012, 07:31 AM
Just say " I do not know", if we as home inspectors would say this more often we would be better off.

Jerry Peck
03-18-2012, 01:46 PM
I can say this: I have yet to see one which will pass the infill 50 psf test and resist the passage of a 4 inch sphere.

Those cables need to be strung tight enough to be able to play music on them to come even close to not moving far enough to resist the passage of the 4 inch sphere.

I've suggested they install twice as many horizontal cables if they want to come close to pass the test of resisting the passage of a 4 inch sphere.

Most will install those cables on 3-3/4 to 4 inch centers, thinking that will suffice, but when you can easily move one cable 1/2 to 1 inch or more with one finger, moving two cables will increase the opening by 1 inch to 2 inches, that means the cables need to be about 2 inches apart, and then the vertical supports need to be space close enough to reduce the movement of the cables to reject the passage of a 4 inch sphere.

Of course, you then end up with a ladder and the kids just climb right up and over it all. There is no way to win that when they want to instal la ladder for the kids to climb over the railing - just tell the people to make sure their kids life insurance is paid up.