How bad did I goof? (Rafter issue)

[SleepyDog]

 



It would seem my rafter has risen...I swore when I screwed these in with the TimberLOK 10 in. Structural Wood Screw, they were flush. Granted, I was using a battery powered drill and had a hell of a time. In hindsight, I should have used something heftier and perhaps predrilled. 

I certainly goofed in cutting the proper birds mouth given the slope - there a lot of goofs in this build...

BUT I am concerned as I have multiple rafters that are not seated on the top plate (hard to tell in the picture but the heel cut of the rafter is not sitting on the top plate either). They hover as shown in the photo. Dead weight on top of the rafters include 2x6 t&g roof decking then flimsy metal roofing. 

Do I need to address this?

[WhitePineJunky]

I'm no carpenter but have built a few things. If it was my build I'd make sure it didn't protrude more than a 1/16 or 1/8th above the neighbouring rafters and if not I'd just jam some cedar shims into the birds notch. I'd they need to go down could sawzall the screws and go at it again to get it seated further down. 

[beenthere]

Sleepy
Looks like the rafter has dried and shrunk, but also standing off on a part not notched out for the top plate (red X)

 



You are prolly correct that predrilling the rafter would have helped but may need to cut out some rafter wood.

[Don P]

I'm trying to figure out that notch, that is the beginning of the problem, that isn't a birdsmouth. We need to talk before you frame again.

Then, explain what the "failure" of this will be or is. I'm not sure I see one. It may not be lovely but where is it going? If you lower it, then you need to pop the tin and snug it all up. If this is just a shed, go and sin no more.

[SleepyDog]

standing off on a part not notched out for the top plate (red X)








I should have taken an additional picture but where you marked it in red is actually off of the plate.

[SleepyDog]

Thanks Don P. It is a single slope roof. I cut in notches, I believed birds mouths were the appropriate term for this?, into the rafters so they would sit flush against the top plates. 

I'll shim and practice on smaller projects before tackling something larger again. Certainly will read more!

[doc henderson]

do you have a farther back pic?  I think Don is pointing out that a bird's mouth would be oriented in the other direction.  but my eyes may not be seeing the orientation of this rafter correctly.  I see a plate and a rafter that slopes up to a peak on the right?  tails to the left, and interior building to the right?

[SleepyDog]

 

 

 

Ah ok. So the first image is the zoomed out shed. Second is the rafter from straight on - If you are looking at the zoomed out version, is is front right, looking towards the back.

My original picture was taken from inside the shed, looking out towards the front.

How are you all drawing on your pictures? Is this done prior to them being uploaded?

[beenthere]

I use Paint to draw on pictures. Very versatile...

Your screws look to be holding the beam from sitting down on the plate. Prolly from the beam/rafter shrinking. But don't think these heavy oversize parts are going anywhere soon.  ;)

I'd be more concerned about the unprotected wood exposed out from under the roof. It will be vulnerable to decay. 

[doc henderson]

what is the pitch (slope) of the roof?

[doc henderson]

another way to scribe a notch for a rafter is to make a board the thickness of the uphill side gap between the rafter and plate/beam.  then lay it on the plate and mark parallel to the top of the beam.  then mark perpendicular at the downhill side.  the purpose of this notch is to resist the theoretical forces to slide the rafter down the hill.  this is why you do not notch the beam to match the rafter angle.  It is not mission critical at what appear to be a miner pitch or slope.

[doc henderson]

a simple way to scribe could be to lay a rafter across.  make a wooden piece the thickness of the gap on the uphill side.  then lay this on the plate along the rafter and mark it.  then make a mark along the back edge of the rafter.  the purpose of the flat bottom notch in the rafter is so that it has not tendance to slide downhill.  not as important with what appears to be a very shallow pitch.  You and your brother-in-law are the only ones who will notice.  And of course, all of us!

[doc henderson]

oops, I thought I lost the first one.  I also tried to paint a mark, but then could not upload as a png.  how did you do that beenthere.  I use the marker in the forum here.

[beenthere]

From Paint, I save the image in .jpeg 

[doc henderson]

 



you would mark both ends, then cut.  so, it all moves down in the same plane.

I agree it is the red chunk marked holding it up, but the notch bottom should be parallel to the plate top.

[Southside]

If you think that's a goof up you should see some of the stuff around here. 

[Don P]

I suspect the threads of the fasteners is in both the rafter and the beam?, if so that can hang it up when it dries and then the beam is free to drift with the notch disengaged. If that is the case make sure the fasteners go through the side piece with either a clearance hole or at least shank only in that piece. Fully threaded deck screws are an example, the threads are in both the deck board and the joist. When the decking and framing dry the deck boards are hung up on screw threads and there is a gap under them. Or another example. We used a lot of 10" lags building log homes with 7" tall logs. The threaded portion is around 4.5" but we piloted through the upper log with a 1/2" bit for a 3/8" lag, you want the logs to be able to slide down as they dry.

All great on paper, sometimes you simply lack the driving weight to overcome the friction of all those "loose" fasteners. I doubt this is worth fixing, more just a learning opportunity.