half lap collar tie

[cgsemrau]

hi,
I am assembling my timber trusses for my cabin this weekend.  The 8x11 rafters for 12/12 pitch roof.  Building is 22 feet wide. 

I was planning to half lap my collar ties into the rafters originally and peg them.  While reviewing half lap vs M&T this week in preparation, I saw some half lap dovetail collar ties.  My question is would these require a peg (or screw)??  The dovetail I believe is fine under compression by itself, but to avoid lateral stress such as a kid swinging off it in the loft, I think a peg or screw makes sense.  

For the half lap  I intended to notch the rafter 1" deep and the 3x8" collar tie  1" deep and place a collar tie on each side of the rafters.

No other notching on the rafter besides Tonge and Fork at ridge and birds mouth at wall plate/log.

I appreciate the help.  Just not seeing a lot on the half lap dovetail in this application with my searches.

[Don P]

Where in elevation is the tie? If these are trusses the tie is very low and in tension to restrain outward rafter thrust.

[cgsemrau]

Hi Don!  This is the cabin roof you helped me with last summer.  I was able to get advice from a local log home builder of 40 years near me.  He was good with what we had, he had some tips for the valley where the roof intersected and offered to walk me through it when I set the trusses in june.

I am focusing on the rafters over the loft area specifically, so no rafter ties.  These are collar ties in the upper third.  the ridge is about 11 feet high, these will be about 8 ft high.