Deck guard rail along window

[mathew stouffer]

The space between the guard and window exceeds 4 inches. However, my question is, are deck guard rails allowed to end next to a window. The place was built in 1980 but the deck was just rebuilt.

[Jerry Peck]

However, my question is, are deck guard rails allowed to end next to a window. The place was built in 1980 but the deck was just rebuilt.


Mat,

That's one of those "Yes, but ... " answers.

"Yes", the guard is allowed to end there provided (as you pointed out) there is less than 4" between the window and the guard.

"But", you then need to address the window as to is it safety glazing or not and is safety glazing required or not.

Also looks like it is going to be a challenge to change the lamp in that light fixture. :)

Also notice how the far right vent hood through the wall is done, then look at the two closer ones - those look like the siding was installed afterward, maybe on top of other siding, but they sure do look like leakers the way they are installed.

[mathew stouffer]

Thanks Jerry.

[Eric Barker]

I think that the post is more of an issue. No way will it stand up to any significant lateral force.

[mathew stouffer]

Eric good call, it was very weak.

[Jerry Peck]

I think that the post is more of an issue. No way will it stand up to any significant lateral force.

That post "may" stand up to the required force, especially if through bolted.

It only has to withstand a 200 pound force anywhere along the top rail in any direction.

I've seen many posts which did not appear to be anchored even that well withstand the required test.

The guard in-fill panel only needs to withstand a 50 pound load applied to one square foot area.

You have brought up an excellent point and something which needs to be looked at at every guard.

[Jerry Peck]

Eric good call, it was very weak.


I was typing as Mat posted, if it was very weak, then Eric is probably correct.

[Eric Barker]

Believe it or not, 200 pounds on the top of a regulation height post will equate to 1,700 pounds at the base. Even 4x4 posts through bolted have failed at such pressure. No matter how the post in the picture is secured, it cannot meet the requirement.

[Jerry Peck]

Believe it or not, 200 pounds on the top of a regulation height post will equate to 1,700 pounds at the base.

Not having done the math (and not doing the math because it is beyond me with all the variables involved, it is not just a simple lever) I cannot say that you are correct or incorrect on your answer.


Even 4x4 posts through bolted have failed at such pressure. No matter how the post in the picture is secured, it cannot meet the requirement.

I've have seen just the opposite - that those anchors do hold and resist the required load - depending on the angle, the fastener, and the installation.

If a 4 X 4 post fails (the post itself) at 200 pounds on the top, then you have a defective post. I have personally pulled the tops of 4 X 4 posts with a one ton Come-A-Long winch and strained at pulling it, without having measured the pressure I am sure it exceeded 1000 pounds at the top and the post did not break.

Regarding failure of that 4 X 4 post at its anchors, that would be another defective problem in not using the correct bolts, washer, nuts and through bolting it. If only using small lag screws ... yeah, maybe it would push out at 200 pounds.

That said THAT post was "weak" as Mat, who was there, stated. So SOMETHING was not mounted correctly, possibly small screws into the floor planking instead of through bolting it, we just don't know.

[Eric Barker]

The math was done by Simpson and confirmed by independent university testing. Even additional blocking of the framing around the base of the post turned out to be insufficient. As a result, Simpson came up with this little honey which did holdup to the 200 lbs pressure. Interesting huh? So, from my experience, I've never seen a properly secured railing - and I've seen many that I thought were OK.

Now, do you condemn every post from now on? To do so would seem to invite exceptional ridicule from virtually everyone. Honestly, I don't know where to draw the line. But I am more critical than I used to be.

[Jerry Peck]

The math was done by Simpson and confirmed by independent university testing. Even additional blocking of the framing around the base of the post turned out to be insufficient. As a result, Simpson came up with this little honey which did holdup to the 200 lbs pressure. Interesting huh?

I can tell you that my 200 pounds (and occasionally slightly more, like 210 right now) has not broken off a single top rail I have fallen against, and if you do mass x distance x speed (or whatever the formula is) I am sure there was more than 200 pounds load placed on those top rails.

Looking at that photo you posted of the Simpson braces, they seem to confirm what I said about through bolting and 4 X 4 posts, and probably even the post shown in the photo above if through bolted.

Those Simpson braces are not holding the posts from pulling breaking off or even from pulling through, that is simply holding that POORLY FRAMED corner together so that those bolts CAN DO THEIR JOB by keeping the corner together.

The post shown has compound leverages which would need to be calculated, which is way beyond me, ... BUT ... if you see a CORNER framed as shown in that setup you posted a photo of, that CORNER framing itself should set you off a bit.

[Eric Barker]

Jerry,

I understand what you're saying. My point is that there is interesting info "out there" and that we as inspectors at least need to be aware of it - especially considering what an attorney/hired gun may do with such information.

The last two "knock your socks off" deck presentations that I've been to bowled over (scared the hell out of) most of the people attending. Many inspectors simply have no idea what they're missing in their deck reporting.

[Jerry Peck]

The last two "knock your socks off" deck presentations that I've been to bowled over (scared the hell out of) most of the people attending. Many inspectors simply have no idea what they're missing in their deck reporting.


I have no doubt about that. I would be untrained in decks as I seldom ever saw decks, so I sure it would do that to me too.

[Stephen Meyer]

I have seen those simpson items used on shear walls

[Jerry Peck]

I have seen those simpson items used on shear walls


I could not find them in either their full 2009 Catalog or their 2009 Deck Framing Guide: http://www.strongtie.com/ftp/fliers/DIY-DECKSAFE08.pdf

[Eric Barker]

The connectors are new - not in the catalog yet.

[Jerry Peck]

The connectors are new - not in the catalog yet.


Eric,

I could not even find them on the Simpson web site under what's new for 2009.

How "new" are they?

[Eric Barker]

Jerry,

I was at a Simpson program in April (where I took the picture) and they said that the brackets were not yet in the catalogs.

[Steve Frederickson]

A 200# horizontal force at a height of 36" will result in a bending moment of 7200 inch pounds at the connection. The connection shown would result in a tension in each screw/bolt (assuming two screws in tension and 5" spacing) of about 720# (7200/5"/2 screws). If it's screwed into the decking, it probably is not adequate.

An individaul who weighs 200# is not actually placing a 200# force on the post when he pushes against it, because his feet are still (usually) on the deck, and much of that weight is going vertically to the deck. It's very rare that a deck post will actually see teh required design load of 200#.

The issue that Simpson is addressing has to do with the post attached to the side of the rim board. The board will be in torsion and will pull the nails out that are nailed into the end grain of the joists. The Simpson connector transfers the load into a shear load in the screws that attach the connector to the side of the joist. Here's a good link: http://www.awc.org/Publications/DCA/DCA6/DCA6.pdf See page 16.

Also, attached is information on the Simpson connector. I didn't think that it was all that new, but my memory isn't what it used to be (at least, not that I can recall). http://www.inspectionnews.net/home_inspection/images/icons/icon7.gif

[Steve Frederickson]

I think what's new is the Simpson tension tie, but the Simpson hold-down anchor has been around for years, and it serves the same purpose.
Also, I've found that the rail-to-post connection is usually as much )or more) of an issue than the post connection. I see the rail toe-nailed or toe-screwed to the post. If you get several people leaning against that rail, there can be a disaster.

[Jerry Peck]

I think what's new is the Simpson tension tie,


I found that in the catalogs.

The strap in the photo looks different than that tension tie.

[Jerry Peck]

A 200# horizontal force at a height of 36" will result in a bending moment of 7200 inch pounds at the connection. The connection shown would result in a tension in each screw/bolt (assuming two screws in tension and 5" spacing) of about 720# (7200/5"/2 screws).

Is that accounting for the flat end of the post with the two anchors on each side, which will resist a lever action greater than if anchored differently?

With that post, the two closest screws would be under tension, the two furthest screws would be under compression, and the angle would transfer some of the loading to change the pivot point.

I should say "Would that not be correct" as I am not an engineer and not the math wiz either.

But I do know it takes more to overturn a larger post than a smaller post, even with the same anchors.

[Steve Frederickson]

The numbers were quick and dirty, because it can get complicated. The stiffness of the base plate and the effects of prying action, etc. can play a role. If the plate is rigid (thicker) then all 4 bolts might be in tension to different degrees, with the edge of the plate acting as the fulcrum point. The quick analysis is to assume, in that configuration, that 2 bolts are in compression and 2 are in tension, and the bolts are spaced 5" apart.

A larger post (I assume you mean larger in cross-section) would only be harder to overturn if the bolt spacing is also larger (which is usualy the case). Given the same connection at the base, it shouldn't make a difference as to the size of the post. The post itself might be stronger, but if the attachment at the base doesn't change, the strength of the system isn't any different. It's only as strong as its weakest link. A taller post would be easier to overturn, because you are working with a longer lever.

[Eric Barker]

For further information:
Jerry Tuggle - presented the program
Territory Manager
Simpson Strong-Tie
Columbus, OH
614-850-4063

[Jerry Peck]

Eric,

That photo changes everything related to that strap - yes it is the tension strap shown in the 2009 Simpson catalog and in their deck catalog.

As Steve said "Also, I've found that the rail-to-post connection is usually as much )or more) of an issue than the post connection."

In that photo, the top post bolt is through the anchor bolt hole.

In practice, that top post bolt could be through the wood with a washer with that tension tie anchor being attached to the rim board ... all depends on the placement of that joist and the post.

From your other photo it looked like that was two straps making a 90 degree bend at the corner, simply strapping the corner together. This photo shows what it really is.

[Jerry Peck]

A larger post (I assume you mean larger in cross-section) would only be harder to overturn if the bolt spacing is also larger (which is usually the case). Given the same connection at the base, it shouldn't make a difference as to the size of the post. The post itself might be stronger, but if the attachment at the base doesn't change, the strength of the system isn't any different. It's only as strong as its weakest link. A taller post would be easier to overturn, because you are working with a longer lever.

Correct, I meant 'larger cross section', not 'taller' as being taller would only make matters worse.

[Jim Zborowski]

Jerry, Not a problem changing the light.that's what the rope light is there for, to tie yourself with.:confused:

[gary gramling]

Eric,
Did the Simpson rep explain why they only used one strap instead of one for each bolt?
Gary

[Eric Barker]

Gary, It's the top bolt that's getting the significant outward pressure on it.

[gary gramling]

Correct; and, the laws of physics tell us that rest of the board provides support to the top. But, I prefer overkill.
Gary

[Cobra Cook]

What are we now? sturtual design engineers? Any one who goes to do a home inspection with a come-a-long and tries to break a post is a true idiot. If the post was secured with 4 bolts and does not move when you try to touch or gently shake it, it satisfies the requirement of a home inspection. At that time and momment guys, gals.

[Eric Barker]

What are we now? sturtual design engineers? Any one who goes to do a home inspection with a come-a-long and tries to break a post is a true idiot. If the post was secured with 4 bolts and does not move when you try to touch or gently shake it, it satisfies the requirement of a home inspection. At that time and momment guys, gals.

I don't remember any comment that advocated trying to break a post. What I think you were seeing was comments that went beyond the "requirements" of an inspection. The simple presence of four bolts and the touching or gentle shaking alone will not tell you that a post is properly secured. A well constructed deck (seldom seen) goes far beyond what most contractors and inspectors expect.

While reading a code book will not tell you how to build a deck, it will tell you what the deck must be able to stand up to. To actually meet those specifications would involve what many would consider to be overkill construction. When you consider that a deck should be able to carry 40 pounds live load plus 10 pounds dead load PER SQUARE FOOT in addition to railing resistance requirements you begin to realize how many decks are build wrong.

[dsuser896]

Good info, just what I was looking for. thanks.