# Roofing felt under new metal roof 12/12 pitch. Roofer says #30 felt vertically



## AndyWRS (Sep 12, 2010)

Tom Struble said:


> years ago we used felt run horizontally then a rosin separator run vertically which was the manufacturers spec at the time
> 
> condensation can form on the underside sometimes be nice to know at least your paper is shingle lapped


We haven't used felt under metal in quite some time, i was thinking it needed a slip sheet. Apparently thats not the case anymore and your confirming what i read after checking into it more. I wasn't aware they allowed felt only, we have been using synthetics for years now.

We used to install Metro ( stone coated) direct to deck over 40lb, per there spec. I have been back to numerous old installs like that to do solar tubes, skylights, PV and room additions ect. After removing the roof tile the 40lb was melted to the back of the metal roof panel and would tear the underlayment when removed. It was melted 90% of the way through the 40lb. Based on this observation i assumed the SS would react in the same manner.

Imo felt is not the way to go when synthetics are cheaper. We went from 40lb to synthetics and its cheaper for us. That lightweight 10 sq roll is real nice when drying in a steep pitch job.


----------



## loneframer (Feb 13, 2009)

Tom Struble said:


> if your confident water will never get under it there's no difference


Even in the case of condensation, I don't see why water wouldn't act like water and run downhill. Am I missing something in the bigger picture?:blink:


----------



## Red Adobe (Jul 26, 2008)

Condensation isnt much of an issue with metal unless its open framed over a heated space in a humid area.......In other words in residential over a deck its rarely going to happen unless their is massive heatloss thru the attic and no venting


If you think cap nails are weather proof your high and need to share with the group


----------



## 01chevduramax (Oct 3, 2013)

I didn't mean he would literally want thousands more to run it horizontally. I just meant if He said his original bid on this roof was for installing the felt vertically as he screwed down the standing seam panels, and doing it another way would cost way more, then I would probably not pay a bunch more for it. 

I have asked 20+ contractors out here as I run into them about this question. 3 said they have seen it this way in Oregon with no problems. The others all said they would never run felt vertically in any situation. That it is incorrect. Not one person out here says to use synthetic. Every guy said the same thing about not breathing, and leading to issues with rot in the roof. 

Maybe in our climate the synthetic stuff just does not perform well. I have seen a steep decline in Tyvek and like products here. Only the cheapest spec homes use it. And even the roofs on these roofs are always felt. Though Comp roofing is always used on these spec homes.


----------



## Fender (Jul 22, 2013)

01chevduramax said:


> So it seems like we have 3 choices here.
> 1. Let the roofer do his thing
> 2. Use titanium (lapped horizontally)
> 3. Use felt horizontally
> ...


Never ever ever use Tyvek where we live man! You'll be tearing off your siding, etc in a few years and repairing a ton of rot. The guys in here criticizing felt and saying Tyvek is ok just don't understand the conditions we live in. The local material providers here don't even carry Tyvek or Typar or any of that garbage. One of our local inspectors pushes felt over anything else because its tried and true. We know it'll last 30-40 years if everything is done right. You'll be lucky to get 5 with Tyvek. Whoever did your parents siding is right. Listen to them.


----------



## Fender (Jul 22, 2013)

01chevduramax said:


> I didn't mean he would literally want thousands more to run it horizontally. I just meant if He said his original bid on this roof was for installing the felt vertically as he screwed down the standing seam panels, and doing it another way would cost way more, then I would probably not pay a bunch more for it.
> 
> I have asked 20+ contractors out here as I run into them about this question. 3 said they have seen it this way in Oregon with no problems. The others all said they would never run felt vertically in any situation. That it is incorrect. Not one person out here says to use synthetic. Every guy said the same thing about not breathing, and leading to issues with rot in the roof.
> 
> Maybe in our climate the synthetic stuff just does not perform well. I have seen a steep decline in Tyvek and like products here. Only the cheapest spec homes use it. And even the roofs on these roofs are always felt. Though Comp roofing is always used on these spec homes.


Whenever I see anything other than felt I just assume they're from the valley or out of state. Definitely not coastal. If you want to use Tyvek, you better put felt over it lol.


----------



## Okiecontractor (Oct 15, 2012)

Randy Bush said:


> If I remembering right , think the 3' stuff is 29 guage. would have check to make sure.


Insurance companies around here wont allow us to use 29 gauge. Has to be 26 or better. I guess cause of all the hail we get. Crazy the difference in weight.


----------



## roofermann (Jun 8, 2013)

01chevduramax said:


> I didn't mean he would literally want thousands more to run it horizontally. I just meant if He said his original bid on this roof was for installing the felt vertically as he screwed down the standing seam panels, and doing it another way would cost way more, then I would probably not pay a bunch more for it.
> 
> I have asked 20+ contractors out here as I run into them about this question. 3 said they have seen it this way in Oregon with no problems. The others all said they would never run felt vertically in any situation. That it is incorrect. Not one person out here says to use synthetic. Every guy said the same thing about not breathing, and leading to issues with rot in the roof.
> 
> Maybe in our climate the synthetic stuff just does not perform well. I have seen a steep decline in Tyvek and like products here. Only the cheapest spec homes use it. And even the roofs on these roofs are always felt. Though Comp roofing is always used on these spec homes.


It's a labor cost thing, with the vertical felt, he can install it as he installs the panels. Horizontaly, he'd have to set up staging to install the felt and then remove staging to install the panels. Let him do it his way.


----------



## Designed2Fail (Apr 10, 2013)

01chevduramax said:


> The contractor that will be installing the roof on my new home says he is going to run #30 felt VERTICALLY up the roof pitch (12/12). I understand that will be way faster, and probably safer. But it CAN'T be better for me. The Contractor who is framing the house is outstanding. I trust what he says as much as a family member. He says that it is fairly common to do it this way on steep roofs. Mostly to avoid walking on the rows of paper possible ripping them, or worse slipping off the roof. I am acting as general contractor on this. I feel like I should say NO to vertical felt and incur any additional costs.
> Please give me some advise here. Anyone who has a metal roof please chime in. Was your underlayment done vertical? Any problems??
> This is happening in less than 2 weeks time.
> PS the peak of the roof is 31' above ground.


We have done vertical ice and water barrier vertically on standing seam metal roofs before as that is what was specked out. Never a residential home though.

He just wants a easy way out IMHO as he does not want to deal with the extra work necessary to deal with laying it normally. 

However if you were going totally Ice and water Shield I would go vertically assuming your seams were offset from the panels.

Nothing worse than a grommet screw failing above a over lap. Its evan worse on a tile roof.


----------



## 01chevduramax (Oct 3, 2013)

UPDATE:
The roof is nearly complete. Maybe 1/2 a day left. It looks amazing. I will post some pics up soon.
The 30# felt was run vertically up the back section of the house, and horizontally everywhere else. They did not paper the roof as they installed panels. They papered the entire roof, then came back to install roofing. I have never seen a metal roof installed before. I had some ideas about how they would get the panels up there. BOY was I way off. I feel bad for the crew. The roof was a nightmare. The sections on the back of the house are 31' long. The peak is about 30' high. I always felt like I was pretty manly, I cut the hole for my chimney and installed the stainless roof jack. That job sucked. These guys are animals, working up there 10 hours straight. I would have fallen and died after 3. 
My only worry so far is that there is a lot of small surface scratches on the raised sections of the panels. From walking, moving other panels, etc. Hopefully that is no big deal. I don't see how it could be avoided.


----------



## J-Peffer (Mar 3, 2007)

I've never ran felt vertically but I could see how installing long standing seam panels it would go faster and easier.

With the 5/8" ply were they using clips? I've repaired quite a few roofs that builders used 5/8" ply because code does not require it to be clipped, and they buckle causing leaks. In my opinion, OSB is a better roof deck material because of this. Especially with the rain it sounds like you are taking on during your build. 

Standing seam roofs expand and contract, and over the length of a panel it can be a good amount. They are not fail proof systems, despite the design making them appear to be. Around here, ice still accumulates on and in seams and builds up before being shed off. Code still requires Ice & Water guard installed 2' beyond conditioned walls here.

The builders we install for, generally want the roof deck kept dry and the inside of the house dry for the other subs. We use high temp ice and water on the entire roof. 

Synthetic felt is a roofers best friend. But as stated above, staple or nail it down and water is getting under it. The stuff is amazing, fast and saves time, but even with a cap nailer I don't sleep at night if shingles don't go over it the same day.


----------

