Ridge board question

[Marc M]

So there is this framing issue in a townhouse where the is not ridge board, no gussets and, the rafters are not opposing. There is, however, blocking between the rafters. I did observe support via a cripple wall and via beam which I assume relieves some of the load from the rafters.
Just checking in to verify so I dont look like an JA calling this out, if its acceptable.

[joe keresztury]

Marc, not only is it an improper frame from what you noted and as seen in pics, but also there are no collar ties installed as required, connecting the rafters at the upper third of roof frame.

[John Kogel]

The lap joint where the rafters meet and the kneewall and beam support are holding the roof up. It is unconventional, so you could suggest the whole complex be inspected for signs of failure. Go ahead and be a JA. :D

[James Duffin]

The NC code says they have to be opposing so in NC it would be wrong.

[brian schmitt]

if it had a permit(doubt it) and engineering then it might be acceptable. check with the ahj.

[Jerry Peck]

The reason the rafter are supposed to be opposing is so they transfer their loads to each other (one opposing rafter to the other opposing rafter), so ... IF that joint is secured properly ... and IF there is sufficient wood at the lap (too bad they square cut one of the rafter ends) ... then the transfer of forces from one opposing rafter to the other opposing rafter is accomplished - right?

Not saying the above is the correct way to do it, just that the reason for the opposing rafter design is still accomplished.

Then there are those knee walls which are supporting the rafters, no collar ties would likely be required.

That said, but ... there does not appear to be a fire-rated wall separating the attics from each other. At best ... that looks like it may be a draftstop wall ... THAT would be my biggie item.

[joe keresztury]

Jerry, the knee walls as you say are supporting the rafters - which is the same as purlins would from being overspanned/ sagging. OK but, that is totally different than what collar ties are required for. Collar ties that are required by IRC serve the purpose of preventing rafter uplift seperation.
Collar Ties, Rafter Ties, Purlins and Braces | JWK Inspections (http://www.jwkhomeinspections.com/blog/collar-ties-rafter-ties-purlins-san-antonio-home-inspector.html)
:)

[Jerry Peck]

Jerry, the knee walls as you say are supporting the rafters - which is the same as purlins would from being overspanned/ sagging. OK but, that is totally different than what collar ties are required for. Collar ties that are required by IRC serve the purpose of preventing rafter uplift seperation.
Collar Ties, Rafter Ties, Purlins and Braces | JWK Inspections (http://www.jwkhomeinspections.com/blog/collar-ties-rafter-ties-purlins-san-antonio-home-inspector.html)
:)


Yes, knee walls and collar ties are for different purposes, however, on a short height roof such as shown, with knee walls as shown, the effect of the knee walls (instead of purlins) could very well replace the usefulness of collar ties.

Let's say you have a ridge beam, would you need to have collar ties? No.

Those knee walls are not the same as a ridge beam, but their apparent (from the photos) close proximity to each other suggests that the attic is not large (span or height) and that those could very well serve the purpose of collar ties.

Once you get into unconventional framing you need to look for the purposes for the components being provided by the unconventional framing methods. Or you could just recommend a structural engineer design appropriate repairs, and "appropriate repairs" includes "no repair". ;)

[joe keresztury]

Jerry, Thanx for the wink, I'm flattered. I don't want to debate w/ you - I don't have time for another 17,000 thousand of your posts. I know you are the champ here. The only difference between Champ and Chump is U (you). However rafters should be opposing and collar ties are required. Nuff said. Go find GW Watson to debate with. :D :D ;) LOL
I do enjoy reading your posts.

[Marc M]

The reason the rafter are supposed to be opposing is so they transfer their loads to each other (one opposing rafter to the other opposing rafter), so ... IF that joint is secured properly ... and IF there is sufficient wood at the lap (too bad they square cut one of the rafter ends) ... then the transfer of forces from one opposing rafter to the other opposing rafter is accomplished - right?

Not saying the above is the correct way to do it, just that the reason for the opposing rafter design is still accomplished.

Then there are those knee walls which are supporting the rafters, no collar ties would likely be required.

That said, but ... there does not appear to be a fire-rated wall separating the attics from each other. At best ... that looks like it may be a draftstop wall ... THAT would be my biggie item.

The wall separation was particle board, 1/4".

[Jerry Peck]

However rafters should be opposing and collar ties are required. Nuff said.

Joe,

You say "Nuff said.", I already said nuff, then you carried on, so now I have to say mo'.

You need to expand your reading some, first, start with the code, then don't stop when it says "Rafters shall be framed to a ridge board", continue reading where it says "or to each other", then continues to provide ONE METHOD of 'to each other' by saying "with a gusset plate as a tie."

Then go to the the Administrative Chapter where it says: (bold and underlining are mine)
- R104.11 Alternative materials, design and methods of construction and equipment. The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. An alternative material, design or method of construction shall be approved where the building official finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, at least the equivalent of that prescribed in this code. Compliance with the specific performance-based provisions of the International Codes in lieu of specific requirements of this code shall also be permitted as an alternate.

APPROVED. Acceptable to the building official.

I'm not looking to post as often as I used to, which is why I am posting less, but sometimes others post things which just simply cannot be left as nuff said 'caus dey is wong. :rolleyes:

[Jerry Peck]

The wall separation was particle board, 1/4".

Marc,

Dang, that is not even draftstopping. Holy crap.

[Marc M]

Yes, knee walls and collar ties are for different purposes, however, on a short height roof such as shown, with knee walls as shown, the effect of the knee walls (instead of purlins) could very well replace the usefulness of collar ties.

Let's say you have a ridge beam, would you need to have collar ties? No.

Those knee walls are not the same as a ridge beam, but their apparent (from the photos) close proximity to each other suggests that the attic is not large (span or height) and that those could very well serve the purpose of collar ties.

Once you get into unconventional framing you need to look for the purposes for the components being provided by the unconventional framing methods. Or you could just recommend a structural engineer design appropriate repairs, and "appropriate repairs" includes "no repair". ;)
I thought collar ties were required even with a ridge board/beam?

[Marc M]

Marc,

Dang, that is not even draftstopping. Holy crap.

Hey Jerry, how far back does the separation wall requirement go for townhouses? That you're aware of...

[Jerry Peck]

Hey Jerry, how far back does the separation wall requirement go for townhouses? That you're aware of...

Marc,

The California Building Code (CBC) uses was based on the UBC before going with the ICC codes, and the UBC was first published in 1927, with the CBC approved and incorporated into the UBC in 1988. (From here: Building Codes & Regulatory Resources | Environmental Design Library | UC Berkeley (http://www.lib.berkeley.edu/ENVI/Codes.html) ;) )

Fire separation and protection was always a thing the codes addressed, so I would guess that fire separation between structures (and townhouses are simply structures which are attached) go back that for or further.

Watson is excellent at researching things like this, so he will probably provide better and more specific information, besides, he is older and I think he helped develop the Code of Hammurabi (http://en.wikipedia.org/wiki/Code_of_Hammurabi) :
229. If a builder builds a house for someone, and does not construct it properly, and the house which he built falls in and kills its owner, then that builder shall be put to death.
230. If it kills the son of the owner, the son of that builder shall be put to death.
231. If it kills a slave of the owner, then he shall pay, slave for slave, to the owner of the house.
232. If it ruins goods, he shall make compensation for all that has been ruined, and inasmuch as he did not construct properly this house which he built and it fell, he shall re-erect the house from his own means.
233. If a builder builds a house for someone, even though he has not yet completed it; if then the walls seem toppling, the builder must make the walls solid from his own means.
(shortened and interpreted from the code of Hammurabi by: Building code - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Building_code) )

[Jerry Peck]

The only difference between Champ and Chump is U (you).

Joe,

I see spelling is not your strong suit either ... :p ... the "a" is also different. :D

Otherwise it would be chaump???

[joe keresztury]

LOL Jerry you are the Chaump. :D Take care senoir(SP?).

[Ian Page]

As a side but related topic...If saddle braces are used to connect rafters to ridge boards, are the ridge boards still required to be one size larger than the rafter? Thanks.

[Jerry Peck]

As a side but related topic...If saddle braces are used to connect rafters to ridge boards, are the ridge boards still required to be one size larger than the rafter? Thanks.


"Saddle braces"?

You mean collar ties? I've not heard the term "saddle braces" before.

If so, the answer would be yes, the ridge board would need to be one size larger to that the full face of the angle cut rafter was bearing on the ridge board and not overhanging the bottom edge of the ridge board.

[Rick Cantrell]

""Saddle braces"?

You mean collar ties? I've not heard the term "saddle braces" before."

Maybe he means joist hangers.

[Ian Page]

They are 'joist hangers' of a sort. They are metal 'saddles' which fit over the top of the ridge board and the rafters slide into them in the same way as 'joist hangers'. The advantage is that they allow the rafters to be square cut at the end and form a stronger mechanical attachment (Vs nailing alone) between the ridge and rafter. Typical joist hangers are usually used in making horizontal connections. These saddle braces allow for angled applications, as would be required in roof framing, without angle cutting the rafter. Therefore the increased size of the ridge board (over the rafter) would not be necessary for a nailing surface as the rafter is square cut.

[Luc V. L.]

The reason the rafter are supposed to be opposing is so they transfer their loads to each other (one opposing rafter to the other opposing rafter), so ... IF that joint is secured properly ... and IF there is sufficient wood at the lap (too bad they square cut one of the rafter ends) ... then the transfer of forces from one opposing rafter to the other opposing rafter is accomplished - right?

Not saying the above is the correct way to do it, just that the reason for the opposing rafter design is still accomplished.

Then there are those knee walls which are supporting the rafters, no collar ties would likely be required.

That said, but ... there does not appear to be a fire-rated wall separating the attics from each other. At best ... that looks like it may be a draftstop wall ... THAT would be my biggie item.

Without rafters opposing each other, a ridge beam, or collar ties the rafter loads are transferring through only the fasteners between the lap. The shear strength in those fasteners is relatively weak and the method is unstable. With the sheathing & roofing attached it's probably going to be fine but I'd call it out, especially in shaky Cali.

[Jerome Schrenker]

I would suggest getting an engineers judgment before making a comment that this is not up to snuff. It is very unusual. Might just need some more support or some more nails or strapping.

[Rich Goeken]

Jerry, Thanx for the wink, I'm flattered. I don't want to debate w/ you - I don't have time for another 17,000 thousand of your posts. I know you are the champ here. The only difference between Champ and Chump is U (you). However rafters should be opposing and collar ties are required. Nuff said. Go find GW Watson to debate with. :D :D ;) LOL
I do enjoy reading your posts.


Cold Joe, that was cold...........:(

[Stephen McSpadden]

I am a structural engineer home inspector in Colorado. Without seeing the opposite ends of the rafters I have to assume adequate backspan and adequate attachment. And since the rafters are supported by a cripple wall or a beam there is no need for collar ties.
The cantilevered span from the wall or beam support is not significant and should not be a structural problem, again assuming adequate backspan.
The firewall separation between the units might be a problem.
What I see as a problem is the lack of ridge board directly under the ridge. The plywood or OSB roof sheathing is typically designed to transfer horizontal shear loads throughout the roof diaphragm. Without a ridge board there is nothing for the sheathing board edges to nail into and therefor there is no way for horizontal forces to pass back and forth between the diaphragm sections on either side of the ridge. High wind loads, like in a hurricane, will much more easily damage this roof. But, the caveat is we don't know exactly how the original engineer designed it.
Without any feedback from the original engineer I would call it out as a major problem!

[Jerry Peck]

They are 'joist hangers' of a sort. They are metal 'saddles' which fit over the top of the ridge board and the rafters slide into them in the same way as 'joist hangers'.


Got it - like this, right? (Except these are not square cut.)

Scroll down to page 7 of 15.
http://www.strongtie.com/FTP/coderpts/ner421.pdf

[chris mcintyre]

What I see as a problem is the lack of ridge board directly under the ridge. The plywood or OSB roof sheathing is typically designed to transfer horizontal shear loads throughout the roof diaphragm. Without a ridge board there is nothing for the sheathing board edges to nail into and therefor there is no way for horizontal forces to pass back and forth between the diaphragm sections on either side of the ridge............... I would call it out as a major problem!


So are you saying that all homes with ridge vents are a major problem?

[joe keresztury]

I would suggest getting an engineers judgment before making a comment that this is not up to snuff. It is very unusual. Might just need some more support or some more nails or strapping.
Jerome, you might as well save your clients the money you would charge them for an inspection, and tell them up front to .hire an engineer. This situation is not that tough to give an opion on. As Jerry said it needs collar ties.
;)

[joe keresztury]

"Saddle braces"?

You mean collar ties? I've not heard the term "saddle braces" before.

If so, the answer would be yes, the ridge board would need to be one size larger to that the full face of the angle cut rafter was bearing on the ridge board and not overhanging the bottom edge of the ridge board.

Jerry, a saddle of course is another name for the chimney circket. Knew I could help. :)

Ian, kidding aside, as an inspector do you have pics of this technique of connecting ridge and rafters w/ the "saddle" or is this technique something you saw and liked on the internet that no one uses?

[Ian Page]

Jerry, a saddle of course is another name for the chimney circket. Knew I could help. :)

Ian, kidding aside, as an inspector do you have pics of this technique of connecting ridge and rafters w/ the "saddle" or is this technique something you saw and liked on the internet that no one uses?


Joe

Over the years I have seen them used a couple of times and thought their application and use solved a variety of issues. I never thought to take pics. I did see them in some reference material I have buried somewhere. I'll dig it out and scan it. In the meantime I did contact Simpson Strong Tie. They replied that they have never been one of their product lines - the mystery thickens...

Jerry - I apologize, I am unable to view your last link - it's in PDF format. My laptop balks at PDF files and goes into freeze mode. However, if it is what I think it is - having visted the Simpson website - then no. Similar but not the same. The scan, when I locate the reference, will reveal all.

Going forward with the nailing notion. Am I correct in thinking the primary (only?) purpose for the + sized ridge board is simply to provide an adequate nailing surface for the angled rafters?

[joe keresztury]

Yeh Ian, if you can find any kind of images of that, post it here. I'm curious to see what we're talking about.

[Jerry Peck]

Am I correct in thinking the primary (only?) purpose for the + sized ridge board is simply to provide an adequate nailing surface for the angled rafters?


No, the purpose is that the angled cut rafter end is now longer (because it is cut at the angle) and the entire end of the rafter needs to be bearing on the ridge board, thus the ridge board would need to be one size larger *minimum* (the rafter could be cut such that the ridge board would need to be even larger than one size larger).

[Door Guy]

So are you saying that all homes with ridge vents are a major problem?
I was thinking the same thing Chris. Also, what about truss framing, no ridge board there either.

[Marc M]

Here's a few more pics.

[joe keresztury]

At first glance, I would suppose that the structure was engineered, permitted and inspected. But then there's the particleboard wall. Somebody built it that way for a reason but none jumps out at me. The rafter intersection couldn't be approved without engineering. Beams require engineering. Two story structures require engineering. There should have been an architect involved with lots of items. The particleboard wall for example. Whatever it's purpose, particleboard wouldn't apply for any legitimate purpose.

So you've got a conundrum. Is it an engineered, permitted and inspected building or is it not. If it is, then a few puppies got screwed during the construction. If it isn't engineered,........ well that's worse.

You don't mention the presence or lack of rafter ties. Rafter ties must be present unless an engineer designed around them. Were that the case, I would expect to see framing hardware where the rafters land on the beam and 1 1/2" bearing. I would expect to see a ridge board, even a 1"x so long as the rafters opposed with an ST24 over the sheathing.

You don't mention the rafter dimensions.
The waste vents should be strapped to a rafter at the uppermost 45.
The particleboard is split and I bet that happened during installation.

Are you for real ? :rolleyes: :confused: :eek:

[Marc M]

Hey Joe,
Nice job on the blog post; "Collar Ties, Rafter Ties, Purlins and Braces", good information there...

[joe keresztury]

Hey Joe,
Nice job on the blog post; "Collar Ties, Rafter Ties, Purlins and Braces", good information there...
Collar Ties, Rafter Ties, Purlins and Braces | JWK Inspections (http://www.jwkhomeinspections.com/blog/collar-ties-rafter-ties-purlins-san-antonio-home-inspector.html)

Marc, thank you very much.
How old is this property that we are looking at in the pics- at least 30-40 years? It's been an interesting topic.

[Marc M]

Marc, thank you very much.
How old is this property that we are looking at in the pics- at least 30-40 years? It's been an interesting topic.

Good guess. Its a 1970 townhouse. yea..., it's been a interesting topic and yet, so little banter.:D

[Ian Page]

No, the purpose is that the angled cut rafter end is now longer (because it is cut at the angle) and the entire end of the rafter needs to be bearing on the ridge board, thus the ridge board would need to be one size larger *minimum* (the rafter could be cut such that the ridge board would need to be even larger than one size larger).

Jerry
I think that's what I said, or intended to say. I should have included, "...and bearing point..." after "...nailing surface..." for clarification.

These pics are what I was referring to in earlier posts. As you can see somewhat different to the typical Simpson tie (your reference) and same sized rafter and ridge are used.

[Paul Johnston]

So there is this framing issue in a townhouse where the is not ridge board, no gussets and, the rafters are not opposing. There is, however, blocking between the rafters. I did observe support via a cripple wall and via beam which I assume relieves some of the load from the rafters.
Just checking in to verify so I dont look like an JA calling this out, if its acceptable.

When was the homes built and how did this pass the framing inspection if it is not correct?

[Ken Amelin]

Jerry, the knee walls as you say are supporting the rafters - which is the same as purlins would from being overspanned/ sagging. OK but, that is totally different than what collar ties are required for. Collar ties that are required by IRC serve the purpose of preventing rafter uplift seperation.
Collar Ties, Rafter Ties, Purlins and Braces | JWK Inspections (http://www.jwkhomeinspections.com/blog/collar-ties-rafter-ties-purlins-san-antonio-home-inspector.html)

Joe,
Collar ties are not required when the rafter ties are continuous. Show me the code reference where they are always required.

Also, with the rafters in the original picture nailed against each other at ridge, I wouldn't automatically assume it to be an issue. I would reference that an engineer would have been required to design it and refer to past records. If you look at the picture of the metal saddle ties that some else posted, you can see that nails are used to support the ends of the rafters. This connector also uses nails in shear.

[Marc M]

When was the homes built and how did this pass the framing inspection if it is not correct?

1970...lots of things pass inspection that are not correct. With this, we have no idea about inspections etc...

[joe keresztury]

:)
Joe,
Collar ties are not required when the rafter ties are continuous. Show me the code reference where they are always required.

Also, with the rafters in the original picture nailed against each other at ridge, I wouldn't automatically assume it to be an issue. I would reference that an engineer would have been required to design it and refer to past records. If you look at the picture of the metal saddle ties that some else posted, you can see that nails are used to support the ends of the rafters. This connector also uses nails in shear.

Hey Ken here it is.

IRC 2006 page 244 R802.3.1

Collar ties or ridge straps to ressist wind uplift shall be connected in the upper third of the attic space in accordance with table R602.3(1).

Collar ties should be a minimum of 1-inch by 4-inch (25mm x 122 mm)(nominal) spaced not more than 4 feet (1219mm) on center.

You say that " collar ties are not required when the rafter ties are continuos".
Collar ties are totally different than rafter ties, serving a different purpose. see Collar Ties, Rafter Ties, Purlins and Braces | JWK Inspections (http://www.jwkhomeinspections.com/blog/collar-ties-rafter-ties-purlins-san-antonio-home-inspector.html)

Also, you can't assume a engineer had to have designed the frame in Marcs photos. Also good luck finding records from 41 years ago.

[Jerry Peck]

Jerry
I think that's what I said, or intended to say. I should have included, "...and bearing point..." after "...nailing surface..." for clarification.

These pics are what I was referring to in earlier posts. As you can see somewhat different to the typical Simpson tie (your reference) and same sized rafter and ridge are used.

Ian,

How old is the book those photos came out of? They just look 'old'?

Thank you for those photos, I've never seen those before.

They look like something someone thought of, went on the market, did not work well, and then disappear from the market (usually for good reasons). ;)


:)

Hey Ken here it is.

IRC 2006 page 244 R802.3.1

Collar ties or ridge straps to ressist wind uplift shall be connected in the upper third of the attic space in accordance with table R602.3(1).

Collar ties should be a minimum of 1-inch by 4-inch (25mm x 122 mm)(nominal) spaced not more than 4 feet (1219mm) on center.

Joe,

You need to follow those code references all the way through, collar ties ARE NOT *required*.

Re-read that code section, notice where it refers to Table R602.3(1)? Yeah, go to Table R602.3(1) and see what it says about collar ties: Collar tie to rafter, face nail OR 1-1/4" x 20 gage ridge strap - 3-10d (3" x 0.128").

Now, how do you know if a ridge strap was used or not?

Making blanket statements like "collar ties are required" can sometimes backfire and get you into trouble, things like that make good test questions for the exams, if you are in a hurry and look at R802.3.1 and then answer 'yes, required' you would miss the question as another answer would likely be 1-1/4" x 20 gage ridge strap, and then there may be a 'both' answer.

Collar ties are not "required", they are but one "option".

[joe keresztury]

Ian,

How old is the book those photos came out of? They just look 'old'?

Thank you for those photos, I've never seen those before.

They look like something someone thought of, went on the market, did not work well, and then disappear from the market (usually for good reasons). ;)



Joe,

You need to follow those code references all the way through, collar ties ARE NOT *required*.

Re-read that code section, notice where it refers to Table R602.3(1)? Yeah, go to Table R602.3(1) and see what it says about collar ties: Collar tie to rafter, face nail OR 1-1/4" x 20 gage ridge strap - 3-10d (3" x 0.128").

Now, how do you know if a ridge strap was used or not?

Making blanket statements like "collar ties are required" can sometimes backfire and get you into trouble, things like that make good test questions for the exams, if you are in a hurry and look at R802.3.1 and then answer 'yes, required' you would miss the question as another answer would likely be 1-1/4" x 20 gage ridge strap, and then there may be a 'both' answer.

Collar ties are not "required", they are but one "option".


Jerry, you are absolutley right, collar ties are not always required. Yes, there are other alternatives that accomplish the same thing. I should of said collar ties (most commonly

used) or straps on conventional framing is required and that engineered trusses have gussets designed and installed accomplishing the same thing (which I do mention on my blog

link posted here) Collar Ties, Rafter Ties, Purlins and Braces | JWK Inspections (http://www.jwkhomeinspections.com/blog/collar-ties-rafter-ties-purlins-san-antonio-home-inspector.html). I have never seen straps in lieu of collar ties in my parts, here in S. Texas, since I've been looking

at roof frames since the late 70's. I qouted the IRC here only because of

someone requesting me to give reference. Technically you are right about my blanket statement that collar ties are required. Again, technically there are exceptions to everything.

But in reality that doesn't apply in my parts, just like that 1950's photo of a saddle strap in this thread doesn't exist here and never did unless some one was building a tool shed

and didn't know how to make the rafter cut to the ridge. So, in conclusion, I am not a code compliance inspector, as the Texas Real Estate Commission stipulates that licensed

Inspectors here are not. But on my inspections, collar ties are required (on conventional frame) ! ! But if I ever see straps here in lieu of collar ties :rolleyes:, I will technically reconsider

my position. :rolleyes:

[Ian Page]

Jerry
The reference material is the 1984 (3rd) edition of Carpentry and Building Construction, I have, however, seen them used on several occasions more recently than that but certainly not on new construction. Reply from Simpson is that it is not their product - past or present.