Advice on bucking sheathing

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Eisenfaust8

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I have to replace my roof due to several issues. One problem I have going on is the sheathing bucking along the entire horizontal seams of the plywood. There were no spacing clips provided, and whomever put on the last roof seriously screwed up the ventilation, which I believe led to this issue.

I've been doing some reading online, and it seems that my options are to either A) rip off the decking and reinstall it with H clips (expensive and time-consuming) or B) Use a skil saw to cut down the entire length of the seams to leave an expansion gap.

Further reading seems to indicate that if I use the skil saw method I might need to add support by putting in 2x4 blocking underneath the joints from the inside, something which I can't do for most of the roof thanks to vaulted ceilings limiting access severely.

What should I do? Is there another way to provide support after cutting a gap that do not involve going into the attic?
 
Cut out 2" wide slot and work a (2x4 block one foot long) in and rotate it so you can attach both sheets to it, add 1 1/2" strip back in. Even a shorter piece might be better so you do not block all your vent vent air.
 
What's your location?
Makes a huge difference on how it should have been done.
https://www.energystar.gov/index.cfm?c=home_sealing.hm_improvement_insulation_table
It's rare to find a vaulted or catedral ceiling vented or insulated correctly.
Really want to fix this right once and for all or just a quick fix?
Got some pictures so we can see how bad it is?
What type roofing do you have?
How old are the shingles if that's what's on there?
 
nealtw said:
Cut out 2" wide slot and work a (2x4 block one foot long) in and rotate it so you can attach both sheets to it, add 1 1/2" strip back in. Even a shorter piece might be better so you do not block all your vent vent air.
Click to expand...

Would the 2x4 need to be secured at an angle to the trusses on each end of the board or would it be sufficient to secure both sheets to the 2x4 and leave it at that?
 
joecaption said:
What's your location?
Makes a huge difference on how it should have been done.
https://www.energystar.gov/index.cfm?c=home_sealing.hm_improvement_insulation_table
It's rare to find a vaulted or catedral ceiling vented or insulated correctly.
Really want to fix this right once and for all or just a quick fix?
Got some pictures so we can see how bad it is?
What type roofing do you have?
How old are the shingles if that's what's on there?
Click to expand...

I am in Western WA state which is somewhat humid.

I'd like to fix it once and for all. I can get a picture in a couple days. The roof is architectural shingles installed in '05. The ventilation problem is caused by someone adding roof vents in addition to gable vents and the ridge vent. Every roofer I talked to said that the roof and ridge vents together ruins the flow of air. I blocked off the gable vents and added more eave vents (drilling 2" holes in the eaves) and when I reroof soon, I will take out the square roof vents and have only the eave holes for intake and the ridge vent for outflow. The only problem is that I could not add additional venting to the eaves for the vaulted ceiling portion of the house because I am unable to get down far enough to place the baffles on the inside.
 
Eisenfaust8 said:
Would the 2x4 need to be secured at an angle to the trusses on each end of the board or would it be sufficient to secure both sheets to the 2x4 and leave it at that?
Click to expand...

H clips or blocks are only required for trusses or rafters set at 24" on center.
No they do not need to attach to the truss.
All you are after is to stop the flexing one on sheet edge when you walk on a finished roof. You want both sheets to flex together or you could damage the single if one flexes and the next one stays stiff.
 
A friend just had his roof replaced with much the same issues, no venting over vaulted ceiling, he had the roofer add 1x2 sleepers above the rafters and add another layer of sheeting with a vented drip edge and ridge vent. Now he has a 3\4"airway over the whole roof.
 
nealtw said:
A friend just had his roof replaced with much the same issues, no venting over vaulted ceiling, he had the roofer add 1x2 sleepers above the rafters and add another layer of sheeting with a vented drip edge and ridge vent. Now he has a 3\4"airway over the whole roof.
Click to expand...

Thank you for the reply. I am not quite understanding what you mean by a sleeper and airway. Can you please elaborate?
 
1x2s on top of the old sheeting above the rafters and another sheet over that gives a gap between the old and new sheets so you have a space for air to flow from the lower edge to the ridge vent
 
nealtw said:
1x2s on top of the old sheeting above the rafters and another sheet over that gives a gap between the old and new sheets so you have a space for air to flow from the lower edge to the ridge vent
Click to expand...

Thanks. I can't afford to put up a whole new layer of sheathing, but that is a good idea.

Your idea for cutting out the joints and putting in blocking from above was great. I'm going to do that with 1x4s. I'm going to try to stuff the baffles through the gap and down towards the eave and try to get the venting that way.
 
Eisenfaust8 said:
Thanks. I can't afford to put up a whole new layer of sheathing, but that is a good idea.

Your idea for cutting out the joints and putting in blocking from above was great. I'm going to do that with 1x4s. I'm going to try to stuff the baffles through the gap and down towards the eave and try to get the venting that way.
Click to expand...

If you can't get your baffles in from there and you are cut out for ridge vent, you could slide a length of 1x2 down from there and then flip them up to create some space, maybe 2 per bay.
You might look at vented drip edge also but I think that would require you get behind the gutter to remove some of the liner to allow air flow.
 
nealtw said:
If you can't get your baffles in from there and you are cut out for ridge vent, you could slide a length of 1x2 down from there and then flip them up to create some space, maybe 2 per bay.
You might look at vented drip edge also but I think that would require you get behind the gutter to remove some of the liner to allow air flow.
Click to expand...

As far as I can tell, a vented drip edge will not work because the sheathing extends about 12-18 inches beyond the wall of the house.

After I cut those gaps at the joints, is there any kind of roofing tape I could put down on those seams prior to the felt?
 
Eisenfaust8 said:
As far as I can tell, a vented drip edge will not work because the sheathing extends about 12-18 inches beyond the wall of the house.

After I cut those gaps at the joints, is there any kind of roofing tape I could put down on those seams prior to the felt?
Click to expand...

That 12 to 18 " is what gives you a soffit below and that is the cavity that you are trying to get to when you put baffles in.
No tape needed.
 
nealtw said:
That 12 to 18 " is what gives you a soffit below and that is the cavity that you are trying to get to when you put baffles in.
No tape needed.
Click to expand...

Here's a pic of what I have. The holes are the venting that I have been adding.

That Smartvent product looks like it could be a great solution. My only concern would be it working (or not) in combination with all the holes I've drilled out in the eaves already

[EDIT] Never mind, I just found this on their site.

"Can SmartVent be installed even if there are perforated soffits already installed?

Yes. SmartVent can still be installed even with perforated soffits because you can really never have too much intake ventilation. The ridge vent is going to be your controlling factor so it will still suck air from both the SmartVent and the perforated soffits."

20160608_165048.jpg
 
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