Collar Ties vs. Rafter Ties article upgrade.

[gromicko (Nick Gromicko, CMI)]

Would 1/3 qualify as intermediate in your math?

Yes.

[mcyr (Marcel Cyr, CMI)]

:mrgreen:

Blog of interest here; http://mathscinotes.wordpress.com/2010/11/29/the-mathematics-of-rafter-and-collar-ties/
http://mathscinotes.files.wordpress.com/2010/11/fbd21-e1329941105490.png?w=640

[mgratton (Marcel Gratton, CMI)]

Interesting article and responses.

Lots of different views on the topic at:

http://www.jlconline.com/search.aspx?query=collar+ties

[jkeresztury (Joseph Keresztury, CMI TREC License # 10420)]

@mgratton

Attached is a pic from Canadian Wood Frame Construction by Canadian Mortgage and Housing Corporation (CMHC) which reads in part:

(A) ceiling and roof framing with ridge board;**
**(1) each rafter toenailed to ridge board with four 2¼ in. (57mm) nails
or end-nailed with three 3¼ in. (82mm) nails;
(2)1x4 in (19x89mm) strip nailed to top of collar braces at their centre with
two 2¼ in (57mm) nails when the braces are more than 8ft. (2.4m) long;
(3) ceiling joists butted with splice plate over centre bearing partition. Joists
also nailed to each part of rafters (see [Table 27](file:///C:/CMHC%20Wood%20Frame%20House/english/book/appendix/table27/index.htm) for nailing practice);
(4) collar brace used as internediate support for rafters nailed to each
pair of rafters with three 3 in. (76mm) nails at each end;
(5) ceiling joists toenailed to top wall plate with two 3¼ in (82mm) nails, one each side;
(6) rafter nailed to plate with three 3¼ in. (82mm) nails;

[collar tie](file:///C:/CMHC%20Wood%20Frame%20House/english/features/illustrations/print/fig54.htm) (entrait retroussé, m.) A horizontal member used to provide intermediate support for opposite roof rafters, usually located in the middle third of the rafters. Also called collar beam or brace.

Marcel, the gable roof image (A) you posted w/ this info shows the collar ties at the upper third of roof frame area.

[mgratton (Marcel Gratton, CMI)]

@jkeresztury

Marcel, the gable roof image (A) you posted w/ this info shows the collar ties at the upper third of roof frame area.

I believe they are in the middle third which appears to be acceptable.

[mcyr (Marcel Cyr, CMI)]

Intermediate. ;)

[jfunderburk (Joe Funderburk, CMI)]

@gromicko

Codes often specify how to do something, if you do it, without requiring you to do it.

If it’s a newer, conventional stick built attic without collar ties, I’m writing it up.