Company installed 1/2 inch deck instead of 5/8 by mistake

Just had a new roof installed, a complete rip, the roofing company was contracted to use 5/8 CDX board for my roof deck. They installed 1/2 inch by “mistake”, stated that the lumber supply yard screwed up and sent over 1/2 CDX.

My house was built in the 20’s, I have 2X6X13ft rafters with a 20-24 inch spread. My roof is about 23 squares, with 15 rafters on each side and 2 inch by 3/4 inch furring strips running the length and width of the roof about 4 inches apart. The roof deck were nailed to the furring strips.

The company has offered to rip the roof and install a new one with 5/8 CDX or give me a generous monetary settlement instead of installing the new roof.

Question: Is there a big difference between 5/8 and 1/2 board, they did a great job on the roof with the exception of the using the wrong size roof deck.

Should I take the money or install a new roof?

My biggest concern is the quality and stability of a roof with 1/2 as opposed to 5/8 board?

Thanks for the advice and help in advance…

What you have is fine, standard in fact for 95% of what I see in so cal.

Take the discount. The roofing company stands to loose a lot of money tearing it all off and redoing it with 5/8" ply and this puts you in good position. They should be discounting it a TON to minimize there loss. A new roof at a fraction what it should cost normally is the best option.

We had a similar issue, ours was color, stupid sales rep never informed us they changed color. We shipped what was on the contract, but it was changed via emails to the sales rep and he never passed it to the installation dept. Major discount to avoid having to tear it all off and do it again…ours was a stone coated metal roof, not a comp that was the wrong color.

While 5/8 plywood is certainly better than 1/2 inch due to the additional thickness, it’s not as much of a difference as usual in your case because the new wood was installed over the furring strips which will provide a lot of support. 5/8 is better but 1/2 inch is the norm. I don’t see you having any problems due to the difference in thickness of the two woods. Seems like a fair settlement would be the difference in the cost of the wood. The labor is the same irregardless. 23 sq. would be 69-70 sheets. I don’t know about your area but here the difference in the cost of the wood is about $4 per sheet. So a $300 discount would be fair based on that information. $500 would be more than fair. Anything more than that, especially a lot more than that might be taking advantage of the situation. But then again a deal’s a deal. You stated they did a good job otherwise correct? Compassion and forgiveness or money? You’ll have to decide for yourself.

In our case a substantial discount was needed because the wrong color metal roof was installed. I would have to agree with LC in this situation. My original post of a huge discount really is not justified. The substrate is not visible and 1/2" cdx is considered normal for a new deck here. The appropriate discount is the difference in material cost. I got too wrapped up in my story and was thinking “visible roof color issue”.

Will the manufacturer be ok with the new deck - and ventilation factors - so as to support a factory warranty on materials?

Your first concern should be your local building codes. You can not use 1/2" in NY State to completely re-deck a roof, it’s 5/8" minimum. You’d be floored how many supposed “professionals” are ignorant of building codes.

That being said, I would not have 1/2" on my house.

*edit- Just re-read your post. If you have rafters 24" O.C. then you should be using 3/4" plywood imo. Please talk to a local building inspector.
They may allow 5/8" with the 2" furring strips but it’s always better to ask.

Up here in BC Canada, code is 7/16 OSB or 3/8 plywood. Having 1/2" plywood on 24" centers is fine, hopefully they “H” clipped i t.

I’d be curious to know if they caught it and brought it to your attention or are you the one that noticed it?

[quote=“Tar Monkey”]Your first concern should be your local building codes. You can not use 1/2" in NY State to completely re-deck a roof, it’s 5/8" minimum. You’d be floored how many supposed “professionals” are ignorant of building codes.

That being said, I would not have 1/2" on my house.

*edit- Just re-read your post. If you have rafters 24" O.C. then you should be using 3/4" plywood imo. Please talk to a local building inspector.
They may allow 5/8" with the 2" furring strips but it’s always better to ask.[/quote]

I am actually located in NYS and spoke to the building inspector for my village, I was told via email that 1/2 was acceptable and up to code in NYS. Tar Monkey could you point me in the right direction as far as where the NYS code states that 5/8 in minimum for a re-deck. I have searched the NYS code and can’t find anything.

BTW, i caught the mistake after the roof was done, not the company.

Thanks for all of the help, your advice is much appreciated.

Tar monkey, I would have to see it to believe it!!!
Here in FL, 24 on centers are 7/16.(1/2 inch)
5/8 is unheard of to be installed by any builder unless
The homeowner insist of it.
And the only reason to install 3/4 is because you are installing upgraded decking for a concrete tile roof.

publicecodes.cyberregs.com/st/ny … sec002.htm

Anything 24" O.C. or under requires 5/8". We always use 3/4" on 24" O.C. because I hate driving by 5 years later and seeing the sheathing sag between the beams but it’s not required by code here.

Roof-lover… I don’t make the rules, I just abide by them.

Try this link for sheathing requirements
publicecodes.cyberregs.com/st/ny … par011.htm

I don’t know if it matters or not but this link goes to NY state 2007 codes

[quote=“r20926”]

I know I couldn’t help but be suspicious. I would wonder if the last 5 customers that were supposed to get 5/8" ended up with 1/2". I don’t know how you would find out.

[quote=“roof-lover”]Tar monkey, I would have to see it to believe it!!!
Here in FL, 24 on centers are 7/16.(1/2 inch)
5/8 is unheard of to be installed by any builder unless
The homeowner insist of it.
And the only reason to install 3/4 is because you are installing upgraded decking for a concrete tile roof.[/quote]

I reroofed a McMansion a couple yrs ago that had 7/16" osb over 24" centers.

The sheeting was sagging all over the place and the guy built the house himself so he wasn’t willing to redeck since it would in essence be admitting to doing it wrong in the first place.

This house was also missing flashing in several places, shoddy workmanship across the board.

It looks really nice from the curb though…

IMO 7/16" isn’t even good over 16" centers.
Codes are minimums, that’s all so don’t be afraid to exceed them.

Thanks Tar, appreciate you posting the link to the code. BTW would the fact that I have the furring strips make any difference in the stability of the roof?

Common sense says yes but I’m not a civil engineer. That would be a question for your local building inspector.

Just an fyi, if your local building inspector says it’s ok then it may be something you want to just let fly and not
worry about it. Furring strips add a lot of beef to the roof structure but that’s your call. Many around here still use
1/2" and get away with it. There have only been a couple municipalities that have actually checked the thickness
of the roof decking in all my years of roofing. Most just slow down, look out the window and give the roof a pass.

First off consider this factor… What was the thickness of the existing decking? How old was it? How was it performing at the time removal?

If it is within the building code and worked before i would leave the 1/2" and take the discount. if not then it must be replaced.

I give the company credit for offering to replace the roof. There are way too many times we see and here of companies not being that professional.

If the current existing deck is within the code I would recommend the following…

Take the offered discount from the contractor and enjoy it :slight_smile:
However definetely also get a warranty from them stating that if there are any failures due to the decking they are fully responsible. Have that warranty signed and notarized.