Barge Rafter Questions

Started by ColchesterCabin, September 17, 2012, 09:20:36 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

ColchesterCabin

I am in the process of building a 16x24' stoery and a half. I have gone through a lot of posts and most people are using Purlins to secure the barge rafter. I have a couple of questions:

1.) Is there a recommended dimension of the rake/barge out from the gable end?

2.) My rafters are engineered rafters instaead of the most common 2x10 rafter, therefore, my rafters are engineered with 2x4 thus not giving me the opportunity to cut in a purlin ple see the following picture to hopefully understand my delima



I want to use 2x6  stock for my facia boarding I was wondering if there would be enough support if I used a 2x4 and secured it to the last 2 trusses adjacent to the gable end under the top of the truss as per the photo. then on the outside use a 2x4 between the gable end and the facia board. I understand the logic of using lookouts and cutting them in from the top but if that's not an option will my train of thought with the roofing OSB 15/32" and the supports as I described them be enough support. I know the facia is not intended for structure??
Visit my thread would love to have your input http://countryplans.com/smf/index.php?topic=12139.0
Feel free to visit my Photobuckect album of all pictures related to this build http://s1156.photobucket.com/albums/p566/ColchesterCabin/

PEG688

16" to 18" is pretty common.

On trusses we lay a 2x4 flat and notch the top of the gable , or last truss even if it's a vaulted truss , so you notch out 1 1/2" deep by 3 1/2" wide .  Butt the  "lookout" into the second truss in and nail it thru that truss into the end grain of the lookout, make sure the gable truss is straight and plumb ,  (you should make sure the second truss in is also straight so the plywood layout stays true as well , your connecting the last two truss together with the lookout) and nail down into the top of the gable truss thru the lookout.

Going up the slope of the roof   layout the lookouts on 4' centers so the exposed plywood . roof sheathing 4' joins fall over the top of the lookout.

Once this is done you can nail your barge or rake board to the end grain of the lookout , or you can nail a 2x4 sub barge / rake board to the lookouts and attach your finished barge / rake to it.  IF you're enclosing the rake soffit the sub rake creates a nailer for the  finished soffit. 


Similar to these photo EXCEPT these lookout are on edge , the last truss in this case was lowered by the truss manufacturer to accommodate a ladder framed soffit over hang , you DO NOT want your lookouts on edge , but flat!   

 


   

 
This is exactly what you need to do,

 
When in doubt , build it stout with something you know about .


ColchesterCabin

I get that and thanks Peg. but my trusses are only 2x4 which as you are familiar is only a 1.5x3.5 therefore in my case I don't believe I can notch out the required spacing as it would weaken to much. I could if the notched truss rested on top of the wall but as the picture describes that is not the case. that is why I was looking to spike a 2x4 in the same fashion as the lookouts but from underneath then insert a 2x4 vertical ontop between the barge and the gable giving me a 'L' shaped nailing edge for the barge rafter.



or based on the picutes in the original post should I still make my notches and weaken the top member of the truss?
Visit my thread would love to have your input http://countryplans.com/smf/index.php?topic=12139.0
Feel free to visit my Photobuckect album of all pictures related to this build http://s1156.photobucket.com/albums/p566/ColchesterCabin/

PEG688


Yes, It's done all the time here in the earthquake ravaged PNW.  Generally the truss on the gable end is not a structural truss as it sits over the end wall.

As I stated on your other thread you've over built your gable wall , the only reason to use a vaulted truss like you used would be IF you put sloped window in that gable wall.

You will only be cutting 1 1/2" DEEP notch.

If you don't trust me ask your local inspector.   
When in doubt , build it stout with something you know about .

ColchesterCabin

Not a matter of trust just defies logic. I appreciate your input as it has given me something to seriously consider.
Visit my thread would love to have your input http://countryplans.com/smf/index.php?topic=12139.0
Feel free to visit my Photobuckect album of all pictures related to this build http://s1156.photobucket.com/albums/p566/ColchesterCabin/


ColchesterCabin

also just thought of it can I 3/4" notch both the lookout and the rafter to allow only a 3/4" notch? Just curiosity...
Visit my thread would love to have your input http://countryplans.com/smf/index.php?topic=12139.0
Feel free to visit my Photobuckect album of all pictures related to this build http://s1156.photobucket.com/albums/p566/ColchesterCabin/

davidj

Typically the truss that's in the line of the end wall has vertical e.g. 2x4s for attaching the wall sheathing.  So the spans for the truss are actually only 14.5", not the 15' or whatever across the cabin that the regular trusses are carrying.  If you only have a regular truss in the end wall you can just add the studs yourself (indeed you need them anyway, if only for the joints at the edges of the sheathing).  And apart from the framing, you get a huge amount of strength from the sheathing too.

In effect this is no different from where top plates meet - there you have a 14.5" span with a flat 2x4 or 2x6 supporting it.  Here there's a 14.5" span with a vertical 2x3-ish member supporting it.