# Advice on bucking sheathing



## Eisenfaust8 (Jun 6, 2016)

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?


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## nealtw (Jun 6, 2016)

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.


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## joecaption (Jun 6, 2016)

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?


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## Eisenfaust8 (Jun 7, 2016)

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.



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?


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## Eisenfaust8 (Jun 7, 2016)

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.
> ...



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.


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## nealtw (Jun 7, 2016)

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?



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.


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## nealtw (Jun 7, 2016)

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.


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## Eisenfaust8 (Jun 7, 2016)

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.



Thank you for the reply. I am not quite understanding what you mean by a sleeper and airway. Can you please elaborate?


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## nealtw (Jun 7, 2016)

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


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## Eisenfaust8 (Jun 8, 2016)

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



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.


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## nealtw (Jun 8, 2016)

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.



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.


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## oldognewtrick (Jun 8, 2016)

On vented drip edge, you cut an inch off the decking to allow for air intake.


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## nealtw (Jun 8, 2016)

oldognewtrick said:


> On vented drip edge, you cut an inch off the decking to allow for air intake.



Would you post a photo of that drip edge
The board at the end of the trusses we call a liner' We have installed 2x3 low to allow for vented drip edge


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## oldognewtrick (Jun 8, 2016)

http://www.airvent.com/index.php/ve...rip-edge/34-vented-drip-edge-intake-vent/file


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## nealtw (Jun 8, 2016)

oldognewtrick said:


> http://www.airvent.com/index.php/ve...rip-edge/34-vented-drip-edge-intake-vent/file



https://dl.dropboxusercontent.com/u/1580852/ALL_ACCESS/INSTRUCTIONS/sv10IT.pdf

So they do call for 1/2" gap so on lower pitch roof you will need more than 1' cut back.


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## Eisenfaust8 (Jun 8, 2016)

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.



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?


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## oldognewtrick (Jun 8, 2016)

Are the sofits open or closed?


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## oldognewtrick (Jun 8, 2016)

http://www.dciproducts.com/html/smartvent.htm

Try this product.


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## nealtw (Jun 8, 2016)

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?



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.


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## Eisenfaust8 (Jun 8, 2016)

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.



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."


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## nealtw (Jun 8, 2016)

Eisenfaust8 said:


> 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
> 
> ...


Sorry I got that wrong, I thoght you were drilling holes in plywood soffets which would hide all that, that 2x4 you have drilled is not usaully there when the soffet is covered.


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## Eisenfaust8 (Jun 20, 2016)

Okay guys, the job is set for this week and it looks like rain showers on the tear off days. 

What do you recommend? I'm thinking of tearing off one section at a time and tarping as I go and then putting down the felt for each section before moving to the next. Time-consuming pain in the butt, although it's the best I could come up with. 

Recommendations?


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## nealtw (Jun 20, 2016)

Up here rain is always a problem, They just don't start when it's a rain storm, but they always just remove in sections and make that water tight before moving on, then when it does rain they just stop that process and start installing the new roof on the prepared areas, when the rain stops they go back to the first job.
We seldom see felt anymore, they have been using a dark colored wrap that looks like house wrap made for roofs.


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## Eisenfaust8 (Jun 20, 2016)

nealtw said:


> Up here rain is always a problem, They just don't start when it's a rain storm, but they always just remove in sections and make that water tight before moving on, then when it does rain they just stop that process and start installing the new roof on the prepared areas, when the rain stops they go back to the first job.
> We seldom see felt anymore, they have been using a dark colored wrap that looks like house wrap made for roofs.



Is it okay to put shingles on top of wet underlayment? What about putting underlayment on some decking that has become wet? Will it dry with proper ventilation under the sheets?


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## nealtw (Jun 20, 2016)

Eisenfaust8 said:


> Is it okay to put shingles on top of wet underlayment? What about putting underlayment on some decking that has become wet? Will it dry with proper ventilation under the sheets?



They do it on new houses but they are all open and have lots of air to dry, this would be better answered by Oldog or another roofer.


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## oldognewtrick (Jun 20, 2016)

We always try to roof over dry decking and dry underlayments. Sometimes it's unavoidable. Felt paper will wrinkle when wet and the wrinkles will not go away once the felt dries out and will telegraph through the shingles. We only use synthetic's (Titanium, Tiger Paw) and don't have the wrinkle problems that the paper based products do.


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## Eisenfaust8 (Jun 21, 2016)

oldognewtrick said:


> We always try to roof over dry decking and dry underlayments. Sometimes it's unavoidable. Felt paper will wrinkle when wet and the wrinkles will not go away once the felt dries out and will telegraph through the shingles. We only use synthetic's (Titanium, Tiger Paw) and don't have the wrinkle problems that the paper based products do.



Thank you, gentlemen. I'll look into maybe changing that underlayment to synthetic. Good news is that the weather is looking dryer already (of course it could flip back at any time)

Gotta love the PNW


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## Eisenfaust8 (Jun 29, 2016)

Thought I'd come back and let you guys know that the job is finally done. It took five full days thanks to all the repairing that had to be completed. The previous guys cut a lot of corners like not overlapping the felt and not even lining up the sheathing on the rafters in some places. It was exhausting but good to know that it was done right this time. 

Thanks for all your suggestions and help.


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## oldognewtrick (Jun 29, 2016)

We love happy endings, thanks for the follow up.


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