|
Re: Rafter splicing
My understanding is that you cannot splice rafters when steel rafters are used. (2006 IRC 804.3.7) No exceptions are given.
When the roof structure is wood, I did not find where splicing is directly addressed. However, cutting and notching of rafters is addressed. (2006 IRC R802.7.) The next section (R802.7.1) addresses sawn rafters and says in part (bold is mine)
" Notches in the ends of members shall not exceed one forth of the depth of the member. The tension side of the members 4 inches (102mm) or greater in nominal thickness shall not be notched except at the ends of the members."
Usually when I see the pictured splicing, it has a run of 2x2 nailed beneath the rafter splice and no brace to bearing. Length of the notches and the "bracing", as the builder calls the 2x2 vary.
Life is easier for me. 95% of my work is in a hurricane zone. Splicing of roof members is permitted, but specific methods are dictated. A splice clearly is right or wrong. In this hurricane zone the splice will have 1/2 inch or better Plywood or OSB scabs on each side and a designed patten of 21 nails per side through each side. The scabs must extend two feet, minimum, both directions from the splice. Bracing to bearing must be placed as close to the splice as possible and cannot be less than 45* from th horizontal.
Almost all splices are butt cuts so that the scab lengths can be the minimum 4 feet. The brace to bearing provision was added in 2003, I believe.
I have to back out today, si I didn't have time to search for a rafter spilce. Here's a picture of a hip splice. The rafter would be spliced the same way.
__________________
The only reason some people get lost in thought is because it's unfamiliar territory.
- Paul Fix
|