Angle of ridge brace or king post - InspectionNews

imported_John Smith · #1 (**permalink**) 10-29-2009, 05:36 PM

Im sure someone will correct me on my terminology (please do, I like to be as accurate as possible). It seems like almost every home I inspect with site built rafters has the ridge brace at some weird angle (like 82 degrees or something) and uses copious amounts of scrap lumber to make up the difference between the top of the brace and the ridge board. I cant find anything specific in IRC, but Im sure there has to be something indicating the proper angle and joint between the brace and the ridge board. See photo for example.

imported_John Smith · #2 (**permalink**) 10-29-2009, 05:40 PM

Oops hit send to quick. Heres the photo. I realize the second photo isnt a ridge brace, but I see the same type of setup used on ridge braces.

John Kogel · #3 (**permalink**) 10-29-2009, 08:53 PM

It's Texas, right? Don't they use adobe with a flat roof no more?

The angle of the brace may be to put the weight over onto a bearing wall? I would point out that the shims at the top make the brace unstable, therefore useless.

Vern Heiler · #4 (**permalink**) 10-29-2009, 10:51 PM

I see these all of the time. I believe the "shim" is really a nail plate, used to provide a bit more meat to drive 16d nails into without blowing the wood up. John K is right the angle is to get to a load bearing point and I think as long as it is greater than 45 deg. (as it is with purlin braces) it is ok.

That radiant barrier sheathing makes it look like a lot more is going on than there really is. The second pic looks like a hip intersecting another roof. The additional 2x2 shim may have been necessary to make up the difference of the sizes of the ridge board, of smaller rafters on one roof, meeting a larger valley rafter of another.

Maybe some of the old framers will chime in?

Ken Amelin · #5 (**permalink**) 10-30-2009, 06:19 AM

My guess is it was a brace used during construction. The framing detail appears to be a standard hip roof, that wouldn't require ridge beam support.

Steve Duchene · #6 (**permalink**) 10-31-2009, 08:06 PM

What kind of crap do they build in your area. Immigrant unskilled labor.

John Kogel · #7 (**permalink**) 10-31-2009, 10:30 PM

Quote:

Originally Posted by Ken Amelin

My guess is it was a brace used during construction. The framing detail appears to be a standard hip roof, that wouldn't require ridge beam support.

In that case, collar ties are missing?

Ken Amelin · #8 (**permalink**) 11-01-2009, 05:15 AM

Quote:

Originally Posted by John Kogel

In that case, collar ties are missing?

"Rafter ties" are not required when ceiling joists (secured properly) are parallel to roof rafters. (which is most commonly done)

John Goad · #9 (**permalink**) 11-01-2009, 06:02 AM

Rafter ties are in the lower third the rafters & are not the same as collar ties which are in the upper third. Rafter ties are to prevent rafter spread & collar ties resist uplift.

John Arnold · #10 (**permalink**) 11-01-2009, 06:41 AM

Quote:

Originally Posted by Steve Duchene

...Immigrant unskilled labor.

How is that different from non-immigrant unskilled labor, Steve?

Nick Ostrowski · #11 (**permalink**) 11-01-2009, 06:54 AM

Quote:

Originally Posted by Steve Duchene

What kind of crap do they build in your area. Immigrant unskilled labor.

Don't hold back Steve. Tell us how you really feel.

John Arnold · #12 (**permalink**) 11-01-2009, 07:17 AM

I hate it when those people come into our country and build crap when we're perfectly capable of building crap ourselves.

Vern Heiler · #13 (**permalink**) 11-01-2009, 05:22 PM

Quote:

Originally Posted by Ken Amelin

My guess is it was a brace used during construction. The framing detail appears to be a standard hip roof, that wouldn't require ridge beam support.

I agree. That also explains the odd angles that we see all of the time. The support is cut a little long intentionally. The carpenters helper moves the bottom of the support laterally along a support wall or joist until the carpenter standing on a ladder says it is level. Then the bottom end is nailed into position. With a hip roof the support is not needed to hold up the roof, but is seldom removed after construction. The second pic I'm not sure about. With out an apposing rafter the support may actually support the end of the ridge board. I would expect to see a larger ridge board if that was the design though.

Quote:

Rafter ties are in the lower third the rafters & are not the same as collar ties which are in the upper third. Rafter ties are to prevent rafter spread & collar ties resist uplift.

As true as that may be, that is not the answer the test writers of licenser boards want.

John Goad · #14 (**permalink**) 11-01-2009, 06:57 PM

R802.3.1 Ceiling joist and rafter connections; Ceiling Joists and rafters shall be nailed to each other in accordance With Table R802.5.1(9), and the rafter shall be nailed to the Top wall plate in accordance with Table R602.3(1). Ceiling Joists shall be continuous or securely joined in accordance With Table R802.5.1(9) where they meet over interior partitions and are nailed to adjacent rafters to provide a continuous tie across the building when such joists are parallel to the rafters.
Where ceiling joists are not connected to the rafters at the Top wall plate, joists connected higher in the attic shall be Installed as rafter ties , or rafter ties shall be installed to provide a continuous tie. Where ceiling joists are not parallel to rafters, rafter ties shall be installed. Rafter ties shall be a minimum of 2-inch by 4-inch (51mmby102mm) (nominal), installed in accordance with the connection requirements in Table R802.5.1 (9), or connections of equivalent capacities shall be provided. Where ceiling joists or rafter ties are not provided, the ridge formed by these rafters shall be supported by a wall or girder designed in accordance with accepted engineering practices.
Collar ties or ridge straps to resist wind uplift shall be connected in the upper third of the attic space in accordance With Table R602.3 (1). Collar ties shall be a minimum of 1-inch by4-inch (25 mm by102 mm) (nominal), spaced not more than 4 feet (1219 mm) on center

Vern Heiler · #15 (**permalink**) 11-01-2009, 07:16 PM

Quote:

Originally Posted by John Goad

R802.3.1 Collar ties or ridge straps to resist wind uplift shall be connected in the upper third of the attic space in accordance With Table R602.3 (1). Collar ties shall be a minimum of 1-inch by4-inch (25 mm by102 mm) (nominal), spaced not more than 4 feet (1219 mm) on center

2006 North Carolina Residential Code (R802.3.1) Is totally different in this section. Wind uplift is not even mentioned here. Go figure! And believe me, the NC test writers want to hear something referring to rafter thrust or spread.

Brad Peterson · #16 (**permalink**) 11-02-2009, 10:19 AM

Good morning John

The only book I count on for standard building practices is the Architectural Graphis Standards- priced a bid high if you want to buy it but a library near you should have it. I like the web site for Journal of light Construction for a reference to framing styles also.
As for your photo's I see more and more of this type of bracing coming from framers with a lack of stick framed roofs. Most of what you show could have been removed after it was decked and nailed off. Ridge beams if framed correctly are self supporting, except in the most extreme case.
Good luck - Brad Peterson - Tri-City Inspection Agency, LLC - Nunn, CO.

Richard Pultar · #17 (**permalink**) 11-02-2009, 10:44 AM

Ridge beams ,if used on on roof with a pitch over 4 on 12 are just oversized ridge boards.They can be self supporting . these Beams don't even need to be there.
A beam that supports a roof at the ridge with a pitch from 4 on 12 down needs support down to foundation.
A board of 1 inch wood or 2X is never a ridge beam.

Wayne Carlisle · #18 (**permalink**) 11-03-2009, 08:46 AM

Quote:

Originally Posted by Ken Amelin

My guess is it was a brace used during construction. The framing detail appears to be a standard hip roof, that wouldn't require ridge beam support.

It may not require a ridge beam support (not a ridge beam though) but it does require a brace where a valley or hip meets the ridge.

John Goad · #19 (**permalink**) 11-03-2009, 09:38 AM

Quote:

It may not require a ridge beam support (not a ridge beam though) but it does require a brace where a valley or hip meets the ridge.

The rest of that code goes on to say, "or be designed to carry & distribute the specific load at that point."
If the rafters intersect the ridgeboard & the hip rafters opposite each other, & the rafters are tied at the ceiling joists, & there are collar ties every 4 feet very little if any support is needed for the hip rafters or ridge board.

Wayne Carlisle · #20 (**permalink**) 11-03-2009, 09:58 AM

John, it looks like you are saying that if the roof is built like the code specifies,

Quote:

Originally Posted by John Goad

The rest of that code goes on to say, "or be designed to carry & distribute the specific load at that point."
If the rafters intersect the ridgeboard & the hip rafters opposite each other, & the rafters are tied at the ceiling joists, & there are collar ties every 4 feet very little if any support is needed for the hip rafters or ridge board.

that you can omit the hip and valley braces at the ridge.

In my opinion the code specifies that the only way these braces can be ommitted is if a design professional specifies a different method of construction.

Ken Amelin · #21 (**permalink**) 11-03-2009, 10:35 AM

Wayne,

It might be your opinion, but that's not what the code says.

"Where ceiling joists OR rafter ties are not provided, the ridge formed by these rafters shall be supported by a wall or girder designed in accordance with accepted engineering practices."

It says OR not AND, ...... So, if "Parallel" and "Continuous" ceiling joists are provided, then No rafter joists are required, No ridge column support is required, AND No design professional is required.

Wayne Carlisle · #22 (**permalink**) 11-03-2009, 12:14 PM

I'm not talking about the ceiling joists or collar ties. I'm specifically talking about the braces that are required under a ridge where valley's or hips abut the ridge.

Here is what I wrote:
In my opinion the code specifies that the only way these braces can be ommitted is if a design professional specifies a different method of construction.

R802.3 Framing details.

Rafters shall be framed to ridge
board or to each other with a gusset plate as a tie. Ridge board
shall be at least 1-inch (25 mm) nominal thickness and not less
in depth than the cut end of the rafter. At all valleys and hips
there shall be a valley or hip rafter not less than 2-inch (51 mm)
nominal thickness and not less in depth than the cut end of the
rafter. Hip and valley rafters shall be supported at the ridge by a
brace to a bearing partition or be designed to carry and distribute
the specific load at that point.

I've never heard the term "rafter joist". Could you please provide a definition?

Brad Peterson · #23 (**permalink**) 11-06-2009, 07:57 AM

Hi every one

The more I read postings on items of concern that inspectors come across in there every day jobs, one item comes as questionable. We seem to be losing our focus that we are visual safety inspectors not lisenced building or code inspectors / engineers. Not that some of us have been in the trades and read the current IRC code book to be more informed.
As a ex contractor / builder (35 Years ) now inspector. I constantly find my self giving my two cents worth on a structure matter but alway try to refer my clients to consult a professional in that field for any question they may have.
But who am I to say I'm just and inspector with an opinion.

Brad Peterson - Tri-City Inspection Agency, LLC- Nunn, CO.

Jerry Peck · #24 (**permalink**) 11-06-2009, 06:10 PM

Quote:

Originally Posted by Brad Peterson

We seem to be losing our focus that we are visual safety inspectors ...

Brad,

Where did you get the idea that home inspectors are "visual safety inspectors"?

Home inspectors are definitely NOT visual "safety" inspectors.

Jerry McCarthy · #25 (**permalink**) 11-14-2009, 10:44 AM

As I have said many times over the years it is my belief that home inspectors are similar to what the medical world calls “General Practitioners.” We perform a visual exam of a building and when we discover minor problems we provide corrective advice and should it be serious problem (material defect) we recommend further evaluation and correction by a qualified specialist.

In other words, we could be called “house doctors” who give a general physical to a home and write a report about the overall condition of its current health... We are not experts in any one area, but rather generalists. The only bummer is we don’t get the fees folks with MD after their name do.

BTW, that roof framing is unacceptable and another example of the sad fact that as construction technology advances craftsmanship retreats. The only upside is that it may provide some sort of job security for the home inspection industry?