deck railing height with built-in benches?

Question

If a deck (more than 30" off the ground) has a row of benches built-in to the perimeter, do the guard rails need to be measured from the height of the bench? I've been reading building codes they all talk about measuring from the floor of the deck.

To clarify: The deck (and the benches, and the house) was built 20+ years ago. I understand that it could be safer, but is that a recommendation or a legal requirement? Is it up to code now, and if not, have the standards have changed recently, or was the original builder in violation?

Answer 1

Holy cow I just went through this last summer with a house I bought...

Specifically, 2009 IRC section R312.2 states: Required guards at open-sided walking surfaces, including stairs, porches, balconies or landings, shall be not less than 36 inches high measured vertically above the adjacent walking surface, adjacent fixed seating or the line connecting the leading edges of the treads.

So yes most/all municipalities that are using 2009 IRC and above would require that you have your rail height 36" higher than the seat. Let me tell you that this is almost impossible to do without a ton of work (and having it functional and looking good). Most people don't want railings at 46-50" since it encloses the deck and is reaching the height of shorter women.

What did we do? We simply detached the bench part and made sure it fit snugly into the deck. Since it is not a "fixed" part of the deck it passed inspection. We were not concerned about small children because it was already 26" over the seat and had vertical backs set at 120 degrees.

Answer 2

The 2015 IRC changes section R312.1.2 Height of guards. From 2015 forward the section on guard height "shall not be less than 36" in height as measured vertically above the adjacent walking surface or the line connecting the nosings." The 2015 IRC effectively rescinds the requirements to measure the guard height from an attached seating bench.

Here is the actual text from 2015:

R312.1.2 Height. Required guards at open-sided walking surfaces, including stairs, porches, balconies, or landings, shall be not less than 36 inches (914 mm) in height as measured vertically above the adjacent walking surface, or the line connecting the leading edges of the treads.

You can see the inline changes shown in this document: http://media.iccsafe.org/news/icc-enews/2015v12n23/sigchanges.pdf

Answer 3

Well you know how kids are.....they climb all over everything. That said be aware that the there are no doubt specific rules to follow regarding how the deck must be constructed. Those rules, whether they be local or something all the way up to and including national building codes, are designed to make structures safe and reliable. If a 40" railing was called for and then you circumvent the safety by putting a 20" high bench next to it you are left with a 20" railing.

I can fully assure you that you would feel pretty bad about it if a kid fell over the edge and died when frolicking around on top of the bench just because you chose to simply measure from the deck surface. In the end I suggest that some conventional deck chairs may very well be a lot more comfortable to sit on than a built in bench.