Collar Ties? Required in all roof framing?

[Buelligan]

According to the following section, collar ties must be in the upper third of the rafter framing. This is to resist uplift. I can't seem to find where in the code it requires this, and when it's required. So does this mean that ALL rafter systems require collar ties or is there a determined point in which they are required to be installed? Such as in wind areas above 90mph. What am I missing?

R802.3.1 Ceiling joist and rafter connections.

Ceiling joists and rafters ...

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 by 4-inch (25 mm by 102 mm) (nominal), spaced not more than 4 feet (1219 mm) on center.

 

[mtlogcabin]

Table R301.2(2) starts at 85 MPH 3 second Exposure B. If you are located within that wind speed or higher then collar ties are required.

 

[Sifu]

From the 15 IRC, 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).

 

[Sifu]

Sorry, didn't read the rest of the question, not what you were asking!

 

[Buelligan]

Table R301.2(2) starts at 85 MPH 3 second Exposure B. If you are located within that wind speed or higher then collar ties are required.

So the short answer is "YES" unless you are in a downtown area, exposure A? Since the entire country is 85 MPH assumed exposure B or higher.

I ask because I was taught by my senior inspector that they were not required and just never questioned it. Well it came up recently and I decided to finally question it because the occasional hand framed roof never seems to use them. Most are engineered trusses any more. So every rafter framed roof I inspect will now have collar ties, unless they can prove exposure A? Just clarifying before I put the foot down or up depending on how you look at it. LOL

 

[Buelligan]

From the 15 IRC, R802.3.1Collar 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).

Yeah I saw that, but that chart is just the fastener requirements IF they are installed. Didn't seem to require them in all cases. But I guess they are required.

Thanks though, I appreciate any replies

 

[jar546]

So the short answer is "YES" unless you are in a downtown area, exposure A? Since the entire country is 85 MPH assumed exposure B or higher. I ask because I was taught by my senior inspector that they were not required and just never questioned it. Well it came up recently and I decided to finally question it because the occasional hand framed roof never seems to use them. Most are engineered trusses any more. So every rafter framed roof I inspect will now have collar ties, unless they can prove exposure A? Just clarifying before I put the foot down or up depending on how you look at it. LOL

This is what infuriates me to no end. If the "senior" inspector does not understand something so simple then what else is he/she lacking in knowledge? I am happy that you came here to get that straightened out. That says a lot about your character.

 

[Sifu]

In every jurisdiction I have worked I have found that far too many contractors AND inspectors have little understanding of collar ties and rafter ties......most think they are the same thing.

 

[Buelligan]

This is what infuriates me to no end. If the "senior" inspector does not understand something so simple then what else is he/she lacking in knowledge? I am happy that you came here to get that straightened out. That says a lot about your character.

I have over the years found that what I was taught early on was sometimes personal opinion and not always necessarily code. I have learned to verify on my own as time allows.