Rafter ends - InspectionNews

wayne soper · #1 (**permalink**) 05-27-2008, 05:08 PM

I am thinking stabilize the ends to prevent twisting. Any thoughts on this.

Jeffrey L. Mathis · #2 (**permalink**) 05-27-2008, 05:28 PM

I'm thinking you're taking this way too far.

Where's the safety concern?

Where is it not functioning as intended?

What will happen down the line that needs observation or attention?

JLMathis

Gunnar Alquist · #3 (**permalink**) 05-27-2008, 05:37 PM

Wayne,

Rafter tails are generally 'frieze" blocked at the eaves (at least, around here). Ceiling joists are often not.

wayne soper · #4 (**permalink**) 05-27-2008, 05:56 PM

Yeah, Gunnar, here also. And way too far is better than not far enough when it comes to whacky home buyers. New house. Not an established builder. Other issues. How long would it take to whack a few stabilizing blocks in there?

Gunnar Alquist · #5 (**permalink**) 05-27-2008, 06:31 PM

Yeah, that could even be done with a rim joist.

Markus Keller · #6 (**permalink**) 05-27-2008, 07:08 PM

Installing some blocking or a rim joist is something I would definitely recommend. I wouldn't write it up as a defect necessarily but as poor workmanship.
The rafter ends and joist ends will twist over time and look ugly. Probably won't have any real effect unless they decide to create storage space. It is possible for the joists to twist enough to create cracks on the ceiling.
I would explain the possible consequences. Unlikely that seller will do much though.

wayne soper · #7 (**permalink**) 05-27-2008, 07:51 PM

Thanks guys, Thats what I thought.

Brandon Chew · #8 (**permalink**) 05-28-2008, 08:50 AM

2000, 2003, 2006 IRC:

Quote:

§R802.8 Lateral support. Rafters and ceiling joists having a depth-to-thickness ratio exceeding 5 to 1 based on nominal dimensions shall be provided with lateral support at points of bearing to prevent rotation.

§R802.8.1 Bridging. Rafters and ceiling joists having a depth-to-thickness ratio exceeding 6 to 1 based on nominal dimensions shall be supported laterally by solid blocking, diagonal bridging (wood or metal) or a continuous 1-inch by 3-inch (25.4 mm by 76 mm) wood strip nailed across the rafters or ceiling joists at intervals not exceeding 8 feet (2438 mm).

Jerry Peck · #9 (**permalink**) 05-28-2008, 09:08 AM

Brandon,

§R802.8 Lateral support. Rafters and ceiling joists having a depth-to-thickness ratio exceeding 5 to 1 based on nominal dimensions shall be provided with lateral support at points of bearing to prevent rotation.

(That's a 2X12 or larger, a 2X10 or smaller does not exceed the 5 to 1 ratio.)

§R802.8.1 Bridging. Rafters and ceiling joists having a depth-to-thickness ratio exceeding 6 to 1 based on nominal dimensions shall be supported laterally by solid blocking, diagonal bridging (wood or metal) or a continuous 1-inch by 3-inch (25.4 mm by 76 mm) wood strip nailed across the rafters or ceiling joists at intervals not exceeding 8 feet (2438 mm).

(That's a 2X14 or larger, a 2X12 or smaller does not exceed the 6 to 1 ratio.)

I know you know that, I'm just pointing it out for all as the joists in the photo do not appear to exceed those ratios.

Jerry McCarthy · #10 (**permalink**) 05-28-2008, 09:14 AM

Here's where the code and I part ways in that if you want "nail-pops" don't block 2x10 ceiling joist. Goodness, I even blocked 2x8, but then I was locally known as the "anal framer."

Jerry Peck · #11 (**permalink**) 05-28-2008, 09:28 AM

WC Jerry,

Keep in mind what we always say "Code is minimum, it is the crappiest one is legally allowed to build to."

Nothing wrong with blocking 2x6 either.

When I was a working general contractor, 'is it code' or 'what does code require' never came up - I did not want to be associated with 'the crappiest I was legally allowed to build to'.

Code is like starting your car or truck up and driving around at idle all day ... it just ain't any fun to go minimum!

Brandon Chew · #12 (**permalink**) 05-28-2008, 09:56 AM

ECJ - Yep. Just wanted folks to know and have a reference for when it is required.

WCJ - I agree. It's a good practice for any depth of ceiling joist if you want to keep your ceiling looking nice.

To All - note that if the attic space will be used for storage, then the floor framing requirements for lateral restraint need to be met. This does not depend on joist depth.

Quote:

§R502.7 Lateral restraint at supports. Joists shall be supported laterally at the ends by full-depth solid blocking not less than 2 inches (51 mm) nominal in thickness; or by attachment to a header, band, or rim joist, or to an adjoining stud; or shall be otherwise provided with lateral support to prevent rotation.

wayne soper · #13 (**permalink**) 05-28-2008, 02:54 PM

It's good to know that what I always did as just good building practice is also what others consider the same. Thanks guys, too bad thats the least of the problems at this home.

Steven Turetsky · #14 (**permalink**) 05-29-2008, 12:27 PM

I'm not even thinking of arguing code and certainly go well beyond minimums when I build something.

But... my question is: when you say 2x10 is does not exceed 5:1, or 2x12 exceed 6:1, well that gets a bit fuzzy to me. As we all know, a 2x10 is not really a true 2" x 10" and so on.

So in reality, how would one apply that code?

wayne soper · #15 (**permalink**) 05-29-2008, 02:30 PM

5 to 1 of the true size would make sense to me.

Jerry Peck · #16 (**permalink**) 05-29-2008, 05:27 PM

Quote:

Originally Posted by Steven Turetsky

But... my question is: when you say 2x10 is does not exceed 5:1, or 2x12 exceed 6:1, well that gets a bit fuzzy to me. As we all know, a 2x10 is not really a true 2" x 10" and so on.

So in reality, how would one apply that code?

Steven,

It's all based on nominal sizes. See my underlined section.

Quote:

Originally Posted by Jerry Peck

§R802.8 Lateral support. Rafters and ceiling joists having a depth-to-thickness ratio exceeding 5 to 1 based on nominal dimensions shall be provided with lateral support at points of bearing to prevent rotation.

Just like span ratings are based on nominal dimensions and not actual dimensions.

Steven Turetsky · #17 (**permalink**) 05-29-2008, 08:07 PM

ahhhhhhh