Best Way to Fix Rafters

[ustmd]

So I am building an outdoor "kitchen"--really a shade and rain structure for the grill. I am using rough cut Western Red Cedar--some purchased new, some reused from other projects.

I am putting a metal roof on part of the structure and that is where I made a rookie mistake. The rafters are 2 x 6. After I got them up, toe nailed in and hurricane clips installed, I realized that the rafters vary +/- 3/16 to 1/4" in width. The differences are enough that if I just put the roof up "as is" the wavy roof line will, to paraphrase my mother, stick out like a women of questionable virtue in a house of worship.

So here is my question, do I take the rafters down and rip them to the same width or just try to shim the purlins to correct for the unevenness?

Taking the rafters down, means pulling the galvanized, ring shank that I used for the toe nails and taking off the hurricane clips. NOrmally not an issue, but since this is cedar, it is pretty soft and most likely the rafters wold take a beating.

Shimming the purlins, means keeping all of the purlins level in two planes (across the rafters for each purlin and from purlin to purlin) which may mean its own set hassles. This is my first time installing purlins, so this may be a normal situation

Thoughts, feedback? Which way would you go?

Here a few pictures of the current build.

 

[Raspy]

Could you just plane the higher ones to match the rest, with a power planer. I'm assuming you mean they are too high, rather than too thick, in other words the "6" dimension varies. Taking them down seems like a lot of work and a lot of damage.

 

[smstonypoint]

Shimming the purlins, means keeping all of the purlins level in two planes (across the rafters for each purlin and from purlin to purlin) which may mean its own set hassles. This is my first time installing purlins, so this may be a normal situation

I am no expert, but I would try the shimming route. It seems to me that you could use string lines to maintain level without too much hassle.

Steve

 

[mehig]

I would lay purlins across the top and simply notch out the rafters so the purlins are straight and level

 

[BuilderML]

When working with regular 2x lumber the crown alone will be beyond 1/4" in height some times. In your case forget taking them down. Do like listed above plane down the high spots and/or shim the low spots. If your thinking taking them down to run them on the table saw which will give you the same result as just taking the planer to them without having to remove them. You could also find your two lowest rafters and use that to set your height and notch the high ones to set your purlins. By no means do you need to make them exact to each other. Lay a straight edge across all of them to see how bad they really are and adjust from there, some of the ones you measure thicker may not be that bad due to the crown of others. Start at the top with your straight edge and work your way down. You have a few options to "blend" everything in.
Have fun.

 

[EddieWalker]

I would get a straight edge on top of the rafters and either notch, sand or shave them in place, depending on how far I needed to go.

Seems like kind of a shame to have to see the underside of the metal through the purlins with that nice cedar you are using. Have you considered a wood ceiling and then laying 30 pound felt paper on it and installing the metal on top? I did one where I just put 2x8's across my rafters as tight as I could get them, then plywood on top of the 2x8's with screws going through the plywood, into the 2x8's. Then I shingled the roof. The final result was very nice from below and above.

Eddie

 

[EddieWalker]

I would get a straight edge on top of the rafters and either notch, sand or shave them in place, depending on how far I needed to go.

Seems like kind of a shame to have to see the underside of the metal through the purlins with that nice cedar you are using. Have you considered a wood ceiling and then laying 30 pound felt paper on it and installing the metal on top? I did one where I just put 2x8's across my rafters as tight as I could get them, then plywood on top of the 2x8's with screws going through the plywood, into the 2x8's. Then I shingled the roof. The final result was very nice from below and above.

Eddie

 

[Eyecatcher]

I'd just go ahead and put the metal on. I don't think you'll notice that small difference from the ground. If you do, you're pretty picky. Women of questionable virtue need church too!!!

 

[paulwestski]

3x on the notching
Standard procedure
When ever you cut rafters you should cut the first one, test it and then use it for the pattern.
Always keep the pattern flush with the top of the rafters.

 

[HillStreet]

Use a string line across the peak and across the eave on each side. Mark heights to the string line, then use a chalk line on the high rafters peak to eave. Either power plane or use a sawzall to remove the higher ones.