This what I posted to Demon about Tyvek under cedar.
Demon said this:
use 15lb felt, cedar will eat up tyvek pretty quick, rendering it useless
I don’t think a house sided 20 years ago with tyvek and cedar would be visibly impaired, but when it’s time to reside, I’ll bet there is water damage where the tyvek has failed.
If you say that cedar will eat up tyvek pretty quick, (how quick you didn’t say) rendering it useless, then don’t you think that you would notice any water damage before 20 years?
If this is true, then how come it’s not heard of all over and why wouldn’t the Cedar Association say that their product should not go over tyvek.
Shouldn’t this tyvek raise a red flag all over like this new ACQ. Isn’t siding homes important enough that there should be testing done on this?
It can’t just be New Jersey who has never heard of this. If this was true than every Architect and every builder all over the country should be talking about it and it should be on the plans that you can’t use tyvek under cedar.
Above was my post to Demon, now there are people here who say you can’t use Tyvek under cedar because of the tanins in the cedar will eat away at the tyvek. So who has proof iof this and why if this is true that is isn’t stamped on every plan in the country that we can’t use it under cedar primed or unprimed?
Every house in New Jersey has tyvek or tarpaper under it both primed and unprimed. So if this is true than all these house will have trouble and every Builder/GC/Subcontractor will be sued using it under cedar.
It should be code not to use it, right?
Should it be in the IRC code or any other code out there.
The people here who say that you can’t use tyvek, are you saying that you can’t use it with preprimed cedar and primed cedar or just unprimed cedar?
Or are you saying that you just know that tarpaper can hold up to anything so it’s just safer using tarpaper?
I’m all for doing the right thing with anything that I do and the reason I’m bringing this up is because I’ve done a lot of cedar siding lately over tyvek and it’s all been preprimed but if there is proof of tyvek turning into swiss cheese and what I install is going to cause leaks in a clients house I want to know about it.
I even ask every Architect I meet about this and they look at me like I have to heads along with all the lumber yards. There’s house going up all over New Jersey that can cost 300k to 3-4-5-6 million useing tyvek under cedar.
I called a rep up about 2 years ago from the Western Red Cedar Asssocaition and he said it wasn’t true. They did studies on it.
This is their site.
So what’s the real deal here and the proof?
Joe Carola
Edited 9/12/2005 8:20 am ET by FramerJoe
Replies
Joe,
The problems usually only show up if the house has moisture transmission problems.
Dupont used to have a fairly explicit disclaimer on their website a few years back. Now it simply has some vaugue wording about "installing the siding IAW the siding manufacturer's instructions" and some blurb about "furring out for a rainscreen might sorta maybe be a good idea."
One of the cedar associations (WRCA?) used to have an explicit warning on their website as well.
I have seen houses where the tyvek had turned to mush, it was in a house with no vapor barrier and myriad moisture problems. Water filled paint blisters on the siding, etc. Real bad. I posted pics several years ago.
Is there a problem?
There could be.
Will the spun-poly industry admit to it? Not as long as their legal departments can keep them from doing so.
Do people install cedar over spun-poly every day? Yup.
But that doesn't mean houses will fall apart. Again, it's about moisture transmission.
Until I hear otherwise...and probably still long after...I'll not install unprimed cedar claps directly over Tyvek. Backpriming and/or rainscreens will be it.
Could I be wrong? Yup.
Could I be right? Yup.
Am I ignorant and apathetic? Well, I really don't know the answer to that one, nor do I care...
<g>
Joe,
check out this article. I had the same question and opted to go with the Tyvek under backprimed(Penofin) T&G horizontal siding. It's to early to tell though, I'll get back to you in 20 years LOL.
http://www.umass.edu/bmatwt/publications/articles/housewraps_feltpaper_weather_penetration_barriers.html
I put cedar clapboard over Tyvek on several homes from 1992-1995. They are still standing, still look good, and haven't heard any complaints from owners.
That gambrel house we did and this clubhouse has or will have cedar shakes as siding and roofing.
Underneath Tyvek. The roofer used that Titanium[synthetic] on the roof....it bleeds ink when wet.
If it were easy....a caveman could do it.
I put Tyvek under my cedar siding 20 years ago and have had no problems. I recently added an addition to the back of the house. This is the north face, no sun, and I have to pressure wash it every year to keep the moss off of it. Pulled the siding off and the Tyvek looked brand new.
NCtim
Framer Joe,
The problem with tyvek and cedar is well documented.. the tannic acid in cedar, (oak and black walnut to name two other woods) attacks the chemicals that make tyvek.. My city insists on using tyveck to deal with the issue I put on the required layer of tyvek and then cover it with 30# felt since I use black walnut for all the beams and trim on the outside of my home..
"The problem with tyvek and cedar is well documented.. the tannic acid in cedar, (oak and black walnut to name two other woods) attacks the chemicals that make tyvek.."How come it's not well documented all over the country if it's so bad?If this is the case no one should be using it. Every Architect, Building Department and lumber yard should know about it like the hardware for ACQ.Still no Architects I talk to have never heard of this and no lumber yards have never heard of this and jobs that I've done additions on with cedar over tyvek that is 15 - 20 years old has no signs of tannins attacking the chemicals in the tyvek.I just finished up an addition on a house that I ripped all the old cedar off that wasn't back primed and the tyvek was in good condition. The tyvek was 17 years old.What are the answers to that? It wasn't eaten by the tanins in the cedar.The rep from The Western Red Cedar Lumber Association emailed me and said that it's not true. How would that benefit him to say that?I'm only talking about this because I've never seen any signs of any tyvek being eaten up from the cedar and ripping apart houses that are 17-18-20 years old with cedar over tyvek and the tyvek being in good condition makes it hard for me to belive that there's a problem.I'm not saying that you and anyone else has never seen tyvek eaten underneath cedar before but maybe there was another problem.Wouldn't you think that all the Architects and Building departments and Builders seminars would know about this and put a stop to this?Joe Carola
Joe, your question got me curious, just checked on a job I did 12 years ago. A board had to be replaced where a flue was being retrofitted. The house is in Long Island with lots of driving weather. Tyvek looks like new!Edit. Remember in the 50's sheetrock was not readily accepted either.
Edited 9/14/2005 8:03 pm ET by TGNY
TGNY,You see what I'm talking about. It's not just me. So far where up to 20 years with tyvek in good shape. So everyone who keeps saying that the tannins in the cedar will eat the tyvek quickly is not true in certain parts of the country.Joe Carola
Edited 9/14/2005 8:21 pm ET by Framer
Framer,
My city doesn't have any information regarding tannic acids attacking Tyvek however Mpls has a warning out to that effect. (as well as several other suburbs in the twin cities area).. just like some places worry about one thing and other cities worry about another it often is a matter of how common is the problem and how aware are the inspectors about that issue..
There is a requirement in my community that calls for no window to be within 50 inches of the top of stairs. Very well enforced. A serious matter that is always looked at, and safety glass verified.. I asked another cities inspector and he admitted he knew about the requirement for safety glass at the bottom of stairs but wasn't aware that there was any requiremnent at the top of stairs.. My point is that there are tens of thousands of rules, warnings and requirements and they tend to be selectively enforced or known about..
I buy Tyvek to satisfy the inspectors and use 30# felt to satisfy myself.. is it more expensive, well sure, but it saves the arguements for the important stuff..
as for your rep from western red cedar, well I wonder how well informed he is and is he concerned that maybe you'd select a wood other than western red cedar if there is an issue with it?
Tyvek is no good
Joe:
Firstly, apologies for not reading the Western Red Cedars possibly self serving report but my general opinion of Tyvek is that we have simply accepted a lot of their claims perhaps in the hope that they're true. After all, seeing a newly framed house turn a bright white on the job site is satisfying and says to everyone passing by that we're getting things done however my personal experience has been that it does not last and because it does not last it cannot possibly do what it claims to do.
As an aside, it is not surprising that Architects don't seem to have anything negative to say about the material because they're not doing the demolition and therefore are not likely to encounter degraded tyvek in the field and question it. They are, in fact, relying more on us than we imagine for that feedback. Clearly we haven't been giving it to them.
On every home and I mean every home I have done renovations on the tyvek has been reduced to swiss cheeze. This makes it useless as a wind barrier, mloisture mitigator and or drainage plane. Conversely, on every home that had felt paper behind the siding the felt was intact and fully functioning. Once the tyvek turns brown and splotchy it's finished. Unwoven fabrics, of which tyvek is in the category of, cannot be torn by hand because there is no grain or woven pattern at which a tear can be started.Tyvek that has been compromised by the tannins that are in both the sheathing and the siding can easily be torn in half and usually has already been eaten away in spots. All of this damage is simply the result of resting against wooden surfaces (surfaces it is suposedly designed to be in contact with).
I recently removed unprimed pine clapboard siding from the back of a garage. The tyvek was covered with brown blotch spots and I could tear the tyvek in half easily. It was essentially useless.
The manufacturers of this plastic covering have not, and probably will not, release information about it's susceptability to the tannins it will inevitably be in contact with. After all, they have the construction industry thinking it is the be-all/end-all of all house wraps and as the "industry leader" imagine how much they have at stake were they to admit their product is incompatible with the environment it is targed to suit.
Other renovators/builders I know hold the same opinion. Now is as good a time as any to help our fellow carpenters, our customers and our industry by joining together to seek alternatives to this misrepresented and often shortlived product.
John Bozak
J. Bozak Construction
Rochester, NH
old thread...
You're replying to a 9 year old thread, so I'm not sure if the original poster is still on the forum. Or if he's even alive.
Same rules still stand as far as I'm concerned. If the cedar is nekked, use lathe to furr out the wall to make a rainscreen. If you want the cedar to be in physical contact with the Tyvek, then backprime the cedar.
For what it's worth, after your post I Googled for "tyvek cedar" images. Found several, but no examples of the sort of deterioration that has been claimed. Several where the Tyvek was stained, but still apparently intact, and a couple where the Tyvek had obviously been damaged in demo. One image where whatever was on the wall was clearly NOT Tyvek (it was a charcoal gray material of some sort). This material WAS disintegrating, but no clue as to what it was or what it had been subjected to.
read this...
Dan, read this with a crtitical eye.
http://www2.dupont.com/Tyvek_Weatherization/en_US/assets/downloads/Tyvek_Cedar%20FAQ.pdf
Read it with the predjudice of already knowing that when bare cedar is in contact with Tyvek and the two become wet, that the surfactants in the cedar can be carried by the water on to the tyvek. Read is knowing that surfacants don't change the properties of the Tyvek. They change the properties of water by reducing the surface tension of the water.
Where water used to bead up on the surface of the Tyvek and not really "wet" the material itself, with the water now having minimal surface tension, the water can now saturate the Tyvek. It's more like a wet piece of paper. With the Tyvek saturated, liquid water can now wick through the Tyvek and wet the sheathing.
It's always a potential factor, But it might not always indicate. It depends on the cedar not being backprimed. It depends on vapor drive. It depends on a lot of things.
If you read the above pdf with a critical eye, they really dance around the issue, but the issue is real. But the pdf is all subtle vaguaries and gentle legalese. The above pdf recommends backpriming the cedar. That takes care of the Tyvek being in direct contact with the Cedar. It defers to the WRCO. The WRCO recommends not using plain ole Tyvek. Instead they recommend using Dupont's version of a rain screen.
The WRCO used to have some very explicit information on thier website regarding bare cedar and Tyvek. They used to have horror story photos of installations gone wrong. But with Dupont and the WRCO now having a sponsorship of sorts, why, all that factual negativity has been replaced with co-sponsored ambiguity.
I've seen some horror show results, they'vre asll been houses that had bare cedar claps nailed ove rht etyvek, then only the show side of the claps were primed/stained. Even FHB had a series several years ago. It's usually inappropriate building practices that lead to the surfactant issue even becoming an issue. Poor building envelops. Poor moisture control.
FWIW, surfactants don't affect Typar like they do Tyvek.
Twenty years ago it was more of an issue, but these days with cedar claps usually coming factory primed, it lessens the chances of bad things happening. I don't know of anyone that installs cedar shingles directly to the Tyvek-covered sheathing. Everyone I know uses furring strips over the Tyvek to hold the shingles off of the sheathing.
I do remember chatter about people that powerwash their house with soapy water, and how that could possibly affect the Tyvek, as soap reduces the surface tension of the water.
I did get sent photos a few years ago about a house that had primed and stained cedar claps installed directly over Tyvek. When the claps were cut to length, the cut ends were not treated. Years later when the siding was pulled to add an addition, there were vertical lines in the Tyvek behind the butt ends of the claps that were not end-primed. Those vertical lines were perforated. The Tyvek had essentially deteriorated and lost it's tear resistance. On the butt joints where the ends were not cut, so theends were factory primed, the Tyvek was pristine.
So I think it can be an issue in certain instances. But with good building practices it shouldn't ever manifest into an issue.
Latest ...
Lastest information suggests non felt papers are fine.
I also think there is a bit of hyteria about underlayments under siding. Millions of homes have been build without any underlayments. In many place you never ever have driving rain which would drive water behind siding. So if you flash properly over doors and windows it will handle any mild normal wetting.
But sure use and underlayment, why not. Worry about it? Not so much.