# Does California Building Code require replacing shiplap with 4x8 Sheathing?



## bimdorf (Dec 4, 2011)

I am a general contractor and I'm rehabbing a house for resale. The asphalt roof shingles need to be replaced. The house is 1950s construction, with 1x8 rabbeted shiplap boards as the roof sheathing. I'm hearing talk that if I tear off the existing shingles, I am required to re-sheath the roof with 7/16" OSB while I'm at it. 

Apart from some very minor repairs at the eaves, the shiplap is in great condition.

Is this in fact a requirement in the state of California? I can't find anything written in the code, but I need to know for budgeting purposes.


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## bkb0000 (Feb 1, 2009)

call the local plans examiner and ask.. they'll be able to give you a straight up "yes" or "no." don't tell them who you are or give the exact address on the property, just ask "if this then this?" so that when they tell you some dumb crap, you still have the option of not doing it. 

if there IS a requirement to re-sheet, please don't use 7/16" OSB, though... there's 50 reasons OSB sucks for roof sheathing, and 7/16 is too thin to offer what little benefit OSB can add to a perfectly good shiplap deck. please use CDX or at LEAST a 5/8 OSB.

my guess is that somebody told you wrong- that he was thinking SKIP sheeting, which you would, obviously, need to sheet over... ignorant people get confused sometimes.


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## aptpupil (Jun 12, 2010)

wasn't needed when they did my roof, but i had them put on 1/2 ply anyway. it stiffens up the whole building and makes it safer for the next generation of roofers. since it's an investment property i understand the urge to save where you can, though, so i'm guessing it's not going to happen unless it's required.


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## jmiller (May 14, 2010)

aptpupil said:


> wasn't needed when they did my roof, but i had them put on 1/2 ply anyway. it stiffens up the whole building and makes it safer for the next generation of roofers.


I don't see how it can be much stiffer than rabbeted 1x sheathing, let alone how it makes it safer for future roofers.


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## DavidC (Feb 16, 2008)

If that shiplap is in sound condition or just needing some repair I'd skip the sheathing, that's a good deck to start on.

Good Luck
Dave


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## aptpupil (Jun 12, 2010)

jmiller said:


> I don't see how it can be much stiffer than rabbeted 1x sheathing, let alone how it makes it safer for future roofers.


are we talking about the same thing? i'm assuming he'd be adding ply on top of the sheathing, hence it would be stiffer. in my neighborhood the rafters are 2x4s over a 16' span so every bit helps.


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## ohiohomedoctor (Dec 26, 2010)

Probably but I heard that stuff causes cancer in cali. :laughing:


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## jmiller (May 14, 2010)

aptpupil said:


> are we talking about the same thing?


Probably not, but skip and ship sound awfully similar.


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## 2ndGen (Apr 6, 2006)

bimdorf said:


> I am a general contractor and I'm rehabbing a house for resale. The asphalt roof shingles need to be replaced. The house is 1950s construction, with 1x8 rabbeted shiplap boards as the roof sheathing. I'm hearing talk that if I tear off the existing shingles, I am required to re-sheath the roof with 7/16" OSB while I'm at it.
> 
> Apart from some very minor repairs at the eaves, the shiplap is in great condition.
> 
> Is this in fact a requirement in the state of California? I can't find anything written in the code, but I need to know for budgeting purposes.


OSB? On a roof? :blink:

I'd suggest you calling your local building department 
(if you haven't been answered here). 

Go directly to the source. They'd know for sure. 

And I'm telling you this as a Building Inspector who's worked for a 
municipal agency and am currently consulting for a private firm now.





bkb0000 said:


> call the local plans examiner and ask.. they'll be able to give you a straight up "yes" or "no." don't tell them who you are or give the exact address on the property, just ask "if this then this?" so that when they tell you some dumb crap, you still have the option of not doing it.
> 
> if there IS a requirement to re-sheet, please don't use 7/16" OSB, though... there's 50 reasons OSB sucks for roof sheathing, and 7/16 is too thin to offer what little benefit OSB can add to a perfectly good shiplap deck. please use CDX or at LEAST a 5/8 OSB.
> 
> my guess is that somebody told you wrong- that he was thinking SKIP sheeting, which you would, obviously, need to sheet over... ignorant people get confused sometimes.


I'm 2ndGen and I approved this message because I believe BKB0000 knows his ship! 

:thumbsup:


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## 2ndGen (Apr 6, 2006)

DavidC said:


> If that shiplap is in sound condition or just needing some repair I'd skip the sheathing, that's a good deck to start on.
> 
> Good Luck
> Dave


*Correctamundo! *










I LOVE coming across T&G board on an old house. 
When I restore the roof on my home, I'm going to use T&G.


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## MJW (Jan 27, 2006)

I sometimes wonder if people are really who they say they are and if they actually do any construction work.........


Tell me why plywood is so much better than OSB and why you wouldn't use 7/16 on top of 1x boards?


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## 2ndGen (Apr 6, 2006)

MJW said:


> I sometimes wonder if people are really who they say they are and if they actually do any construction work.........
> 
> 
> Tell me why plywood is so much better than OSB and why you wouldn't use 7/16 on top of 1x boards?



Sure...

Okay...

Alright...

And once again...


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## MJW (Jan 27, 2006)

2ndGen said:


> Sure...
> 
> Okay...
> 
> ...


NONE of those links prove anything at all in either direction. If any, it points toward OSB as being the choice of contractors, especially those of us that keep our roofs dry.

Most of the pro's and cons were merely opinion.

Ok, now what about using 7/16 OSB over 1X boards? How does this create a problem and why would it not be stronger than not using it over shiplap or skip sheathing?


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## jmiller (May 14, 2010)

MJW said:


> I sometimes wonder if people are really who they say they are and if they actually do any construction work.........


Getting on here and pretending you're a roofer would be more twisted than getting on Craig's List and pretending you're a woman.


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## 2ndGen (Apr 6, 2006)




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## 2ndGen (Apr 6, 2006)

Question: 
Curious; How many here are Roofers? 

(that's all you do...nothing else, you're insured and licensed as a roofer if you have a business or work for a company doing only roofing, don't charge people to do other trades...just roofing)


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## slowsol (Aug 27, 2005)

I would wager that 99.9% of roofs around here and most of the midwest are sheathed with OSB.


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## MJW (Jan 27, 2006)

2ndGen said:


> Question:
> Curious; How many here are Roofers?
> 
> (that's all you do...nothing else, you're insured and licensed as a roofer if you have a business or work for a company doing only roofing, don't charge people to do other trades...just roofing)


I doubt there are very few who limit themselves to one trade.


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## A&E Exteriors (Aug 14, 2009)

2ndGen said:


> Question:
> Curious; How many here are Roofers?
> 
> (that's all you do...nothing else, you're insured and licensed as a roofer if you have a business or work for a company doing only roofing, don't charge people to do other trades...just roofing)


If you sheet your own roof, that rules you out as you're charging for carpenters work. I've never been told that I can't be a roofer and a carpenter, in fact I was a carpenter years before I laid my first shingle.


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## A&E Exteriors (Aug 14, 2009)

MJW said:


> I doubt there are very few who limit themselves to one trade.


He seems to think you can only be good at 1 trade. And for some reason sees roofng as the divine trade


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## 2ndGen (Apr 6, 2006)

MJW said:


> I doubt there are very few who limit themselves to one trade.


You doubt there are very few who limit themselves to one trade? 
Are you saying that you don't believe that there are many general contractors? 
I see it as the opposite. I see very few who "do" devote themselves to one trade. 




A&E Exteriors said:


> If you sheet your own roof, that rules you out as you're charging for carpenters work. I've never been told that I can't be a roofer and a carpenter, in fact I was a carpenter years before I laid my first shingle.


As far as I'm concerned, a Roofer should be able to do anything that has to do with The Roof. I can "do" carpentry, but I'm not a carpenter. I can paint, but I'm not a painter. I can wash my truck, but I'm not an auto detailer. 



A&E Exteriors said:


> He seems to think you can only be good at 1 trade. And for some reason sees roofng as the divine trade


Yes. For me, it is Roofing is divine. That's what makes me a Roofer. If I wanted to make "more" money, I'd do or hire a sub-contractor to do (under my company's name) siding/windows/doors/patios/landscaping/painting/kitchens/bathrooms/dog houses/etc... but I'm not good at caring about that stuff. I have the luxury of being able to focus on one trade and being able to sustain myself with one trade. Even at the worst of times, a good Roofer always has work and doesn't need to compensate. A "businessman" will definitely take advantage of making more sales and combining trades to secure more work. But that's not the question here...
______________________________________

So, can I assume that neither of you are answering "me" to the question of who does only Roofing here?


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## A&E Exteriors (Aug 14, 2009)

Still does not mean I am not a roofer though now does it? 

Yes a roofer should be able to handle his own sheeting, but that doesn't change the fact it is carpentry, and you charge for it.


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## A&E Exteriors (Aug 14, 2009)

2ndGen said:


> You doubt there are very few who limit themselves to one trade?
> Are you saying that you don't believe that there are many general contractors?
> I see it as the opposite. I see very few who "do" devote themselves to one trade.


Does this mean if you limit, or focus on a trade it makes you automaticly better at it than those of us who take on more than one?
I started my career as a framer, then was introduced to roofing on an addition. So does this make me not a roofer even though 98% of my work is roofing/ roofng repairs and the fact that everyone I know in the buisness considers me a top notch roofer with a rigid commitment to quality? Or does it make me not a carpenter?


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## DavidC (Feb 16, 2008)

2ndGen said:


> Question:
> Curious; How many here are Roofers?
> 
> (that's all you do...nothing else, you're insured and licensed as a roofer if you have a business or work for a company doing only roofing, don't charge people to do other trades...just roofing)


Roofing was my entry into contracting and all we (my brother and I) did for the first few years. I've since moved to interior work and hope to stay off the roofs now. But I still seem to manage a few now and then.



MJW said:


> I doubt there are very few who limit themselves to one trade.


The few. The proud. The specialist. 

Usually very damn good at it to boot. The result of focus would be my guess.

Good Luck
Dave


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## 2ndGen (Apr 6, 2006)

A&E Exteriors said:


> Still does not mean I am not a roofer though now does it?
> 
> Yes a roofer should be able to handle his own sheeting, but that doesn't change the fact it is carpentry, and you charge for it.


Semantics. 

Carpentry is part of roofing. 
Like metal work is part of roofing. 
Like masonry is part of roofing. 

Is a roofer a mason? 
A carpenter? 
A metal worker? 

I know plumbers that can flash in their own vent pipes;
are they roofers because they know one aspect of roofing? 
____________________________

Again, you are what you "do" IMO. 
If you only do roofing, you are a roofer. 
If you don't, you aren't. 

Who's got that great quote as their signature about someone 
being a plumber? By Else Bronx? Apples? Something like that! :lol:


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## 2ndGen (Apr 6, 2006)

DavidC said:


> Roofing was my entry into contracting and all we (my brother and I) did for the first few years. I've since moved to interior work and hope to stay off the roofs now. But I still seem to manage a few now and then.
> 
> 
> 
> ...


Exactly. I don't know why someone who does more than one thing and doesn't specialize in one field would get offended by not losing their title of whatever it is they still think they are. 

Nothing wrong with being a "_general_" contractor. 

I love to see crews that specialize in one trade. They usually _are _the best at what they do. They fly, get in/get out, do a high quality job and do great work. They carry the tools they need and efficiency is the name of the game. 

I tried getting out of the weather and did carpentry for a few years, but it just wasn't for me. I love the outdoors too much. I love the change of scenery every few days. I love the time off in the winter.


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## 2ndGen (Apr 6, 2006)

A&E Exteriors said:


> Does this mean if you limit, or focus on a trade it makes you automaticly better at it than those of us who take on more than one?
> I started my career as a framer, then was introduced to roofing on an addition. So does this make me not a roofer even though 98% of my work is roofing/ roofng repairs and the fact that everyone I know in the buisness considers me a top notch roofer with a rigid commitment to quality? Or does it make me not a carpenter?


I'm jealous. 
I wish I knew how to frame as well as I can roof. 
But that's going to take years. 

If you "only" roof now, you are a roofer. 
If you roof and frame and do windows and siding 
and decks (etc...) then you are a general contractor. 

If 98% of your work is roofing then you're a roofer.


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## A&E Exteriors (Aug 14, 2009)

2ndGen said:


> Is a roofer a
> carpenter?
> :


This one is buddy.

Who replaces your busted rafters, reframes the flat porch roofs? You or a carpenter?


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## 2ndGen (Apr 6, 2006)

A&E Exteriors said:


> This one is buddy.
> 
> Who replaces your busted rafters, reframes the flat porch roofs? You or a carpenter?


Me. If it's part of the roof, it's my job as a Roofer to do it.


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## A&E Exteriors (Aug 14, 2009)

2ndGen said:


> If 98% of your work is roofing then you're a roofer.


Glad we finally see eye to eye. Sadly, most of my carpentry is recreacional these days


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## 2ndGen (Apr 6, 2006)

A&E Exteriors said:


> Glad we finally see eye to eye. Sadly, most of my carpentry is recreacional these days


One day, when I'm doing better financially, I'm going to take some time off of work and pimp myself out to a good framer (hopefully one of the good lads on CT) for enough time that I could become a kick-arse framer. I really want to master roof framing. 

BUT! I'm still going to be a ROOFER! :jester:


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## griz (Nov 26, 2009)

fftopic::drink::drink::wallbash:

I AM NOT A ROOFER...:thumbsup:

Back to the OP. My gut says someone got confused with having to sheet over spaced sheathing as opposed to 1x6 ship lap.

In California it is entirely possible that the AHJ may require solid sheathing over the shiplap.

Out here short of changing a light bulb you need a permit. I do not agree with the anonymous approach to the Bldg. Dept. about what do I do. Be up front explain the situation & location & ask how to proceed.

Now as far as OSB/Plywood question...there are thousands of *UNITS* of OSB installed in subfloors, sidewall & roof sheathing every year out here. Are there isolated issues w/ OSB, yes. But there are the same issues with plywood.

We are talking personal preference here, the old Chevy, Ford, Dodge argument. Personally, I have had fewer issues with OSB than plywood.


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## bimdorf (Dec 4, 2011)

Well, thank you all for the answers and the drama from the differing opinions. Turns out you are NOT required to replace the 1x8s with plywood or the dreaded (or exalted) OSB. As long as the deck is in good repair, it's acceptable.

However, the removal of the shingles revealed something just as worthy of a question: two electrical circuits (one 110V 20-AMP and one 220V 40-AMP) were installed between the planks (under the first layer of shingles). We've concluded that this was original construction (based on the labeling of the tar paper under the bottom layer of shingles), but we're still at a loss as to why someone would do this.

#1: there's a perfectly good crawlspace to route a 12/2 and an 8/3 cable
#2: routing both cables under the house would have required LESS materials, as it is a shorter route
#3: if adding these two circuits was an afterthought, it still could have been done through the attic, but from underneath, as the plaster ceilings would not yet have been installed.

Any of several hundred nails could have penetrated these cables, but despite the three layers of shingle, the cables escaped unharmed, which is astounding. The first roofer had the benefit of knowing where the cables were so he could avoid it, but subsequent roofers wouldn't know that the cables even existed.

Here's a photo of the 8/3 cable. The 12/2 is there, but not easily visible:










My question to roofers: have you ever seen electric cables tucked in just under the shingles like this?


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## A&E Exteriors (Aug 14, 2009)

I have, snap a line where the lines run and adjust your course lower at that point if need be, you may not have to adjust anything. You are in the situation the first guy was in, you know where they are.


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## jmiller (May 14, 2010)

I bet 480sparky would like that for his stupidity meets electricity photo collection.


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## bimdorf (Dec 4, 2011)

We pulled the two offending cables out from the service entrance (which we're upgrading anyway) and rerouted them through newly drilled holes. The problem's gone.

There was no way that the building inspector would let us keep the wires tucked under the shingles. It was a really easy fix to reroute (plus I can sleep at night knowing I did the right thing.


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## Splinter hands (Aug 31, 2011)

MJW said:


> I sometimes wonder if people are really who they say they are and if they actually do any construction work.........
> 
> 
> Tell me why plywood is so much better than OSB and why you wouldn't use 7/16 on top of 1x boards?





slowsol said:


> I would wager that 99.9% of roofs around here and most of the midwest are sheathed with OSB.



OSB has not and never will go on ANY roof that I have anything to do with.:no: That is just my preference though.


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## Splinter hands (Aug 31, 2011)

bimdorf said:


> Well, thank you all for the answers and the drama from the differing opinions. Turns out you are NOT required to replace the 1x8s with plywood or the dreaded (or exalted) OSB. As long as the deck is in good repair, it's acceptable.
> 
> However, the removal of the shingles revealed something just as worthy of a question: two electrical circuits (one 110V 20-AMP and one 220V 40-AMP) were installed between the planks (under the first layer of shingles). We've concluded that this was original construction (based on the labeling of the tar paper under the bottom layer of shingles), but we're still at a loss as to why someone would do this.
> 
> ...



WOW:no::no:


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## kage (Aug 17, 2008)

griz said:


> Personally, I have had fewer issues with OSB than plywood.


 This I have in common, OSB or ply I'll put one or the other over shiplap any day!! :thumbup:


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## CHB70 (Apr 22, 2006)

> this i have in common, osb or ply i'll put one or the other over shiplap any day!!


I Agree!


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