# Will properly applied underlayment keep a roof watertight?



## yanceyman1

Well here I am again. Some of you know me already from the posts involving sharkskin and leaving your roof open. After the last few posts to the second one, I figured it was time to put the debate on the table, so here it is...
I am asking all of you qualified journeyman roofers out there, "Can you apply your underlayment and make the roof watertight". Meaning that when your finished, it can sit in a heavy rain storm without leaking. So far, on the one side I have EnglishRoofer, interloc and SlyFox. All of whom are in agreement with me that you CAN base in a house and make it watertight. On the other side of the coin, jasonthompson,Grumpy and gtp1003 say, "Only tear off what you can put back that same day". As absurd as that sounds to me, I am more than willing to listen to hear from more of the roofing community. Please reply with any helpfull insight. I know that it is safer to put it back the same day, but doesn't that hurt production. I have done 110 house housing tracts with tile roofs and because I was trying to keep up with the rockers and painters, I could not afford to use that method. But I also learned that, when done properly, you could leave a based and batted tile job exposed to the weather for long periods of time without a leak. :yes:So there you have it... what do think?
One other thing, jasonthompson, I never said I worked for the "biggest" roofing company in Cailf. I said I worked for the "best". If you don't already know, There is a HUGE difference between the two.


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## rob

*rob*

:laughing:


yanceyman1 said:


> Well here I am again. Some of you know me already from the posts involving sharkskin and leaving your roof open. After the last few posts to the second one, I figured it was time to put the debate on the table, so here it is...
> I am asking all of you qualified journeyman roofers out there, "Can you apply your underlayment and make the roof watertight". Meaning that when your finished, it can sit in a heavy rain storm without leaking. So far, on the one side I have EnglishRoofer, interloc and SlyFox. All of whom are in agreement with me that you CAN base in a house and make it watertight. On the other side of the coin, jasonthompson,Grumpy and gtp1003 say, "Only tear off what you can put back that same day". As absurd as that sounds to me, I am more than willing to listen to hear from more of the roofing community. Please reply with any helpfull insight. I know that it is safer to put it back the same day, but doesn't that hurt production. I have done 110 house housing tracts with tile roofs and because I was trying to keep up with the rockers and painters, I could not afford to use that method. But I also learned that, when done properly, you could leave a based and batted tile job exposed to the weather for long periods of time without a leak. :yes:So there you have it... what do think?
> One other thing, jasonthompson, I never said I worked for the "biggest" roofing company in Cailf. I said I worked for the "best". If you don't already know, There is a HUGE difference between the two.


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## rob

if u ask me i would say no . not 100p cent i have had felt leak wear i have put a crows foot even the smallest hole will piss inn on the pro sark good tube of cillcone middle wall ran up with dry slating ridges on all laps nailed and u might have a chance i had a lap on the felt blow up and the ceilin has come down


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## Gatesroofing

I say Yes you can make it tight enough to resist a rain storm or two. the only difficult part is protrusions but wrapping them over the top with extra underlayment will divert water if necessary. I personally use Palisade synthetic underlayment and would allow it to sit exposed in a rainstorm. Not that id want a roof being open before a storm but if im worried about rain i can make it hold out for a while no problem. I think the only issue i might have is that i use straight staples instead of cap staples so those might leak if the paper gets pulled a little. I never leave roofs open for much longer then it takes to install them as i am a small company.

Marc


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## Valley.Guy

yanceyman1 are you considering differing weather patterns?

Perhaps there are environmental differences between Monterey, CA and my home town of Springfield, IL.

For example, the record maximum 24-hour precipitation for Monterey, CA was 3.85 inches on December 23, 1995.

Whereas, for example, Springfield, IL has receive raintotals of *3.5" - 4.5"* of rain in *three hours* a couple of times this year. These types of downpours are not uncommon in this area. We sometimes get a Monterey monthly rain total in three hours or less here.

Springfield, IL - Last Year Precipitation was 35.56"
Springfield, IL - 2008 Precipitation was 53.73"
Monterey, CA - Last Year Precipitation was 19.85"


I am not trying to cast stones at anyone, however, I believe there is an obvious difference in the environmental factors that everyone may be faced with given the specific geographical local.


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## Gatesroofing

Valley.Guy said:


> yanceyman1 are you considering differing weather patterns?
> 
> Perhaps there are environmental differences between Monterey, CA and my home town of Springfield, IL.
> 
> For example, the record maximum 24-hour precipitation for Monterey, CA was 3.85 inches on December 23, 1995.
> 
> Whereas, for example, Springfield, IL has receive raintotals of *3.5" - 4.5"* of rain in *three hours* a couple of times this year. These types of downpours are not uncommon in this area. We sometimes get a Monterey monthly rain total in three hours or less here.
> 
> Springfield, IL - Last Year Precipitation was 35.56"
> Springfield, IL - 2008 Precipitation was 53.73"
> Monterey, CA - Last Year Precipitation was 19.85"
> 
> 
> I am not trying to cast stones at anyone, however, I believe there is an obvious difference in the environmental factors that everyone may be faced with given the specific geographical local.




I agree fully, whats possible here in cali may not be other places pending the conditions. 

I know i wouldnt even think of tearing off a roof if a storm like that was even thinking of forming..... im a small company so if i dont have at least 3-5 days of clear skys im not touching a roof! My dad had a storm hit years back on an H.O.A. Job and it was hell dealing with the water damage repairs. we wont dare make the mistake again thats for sure.


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## The Roofing God

YES YOU CAN DRY IN A ROOF FOR LONG PERIODS OF TIME without leaks,but it is best to tarp also if you are going that route

New york gets as bad rains as anyone


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## dougger222

Yes you can HOWEVER there are certain items that are tougher to I&W/Felt dry.

1. Step flashing details. If the tins are lifted up which they should be to allow new underlayments under them they could bring in wind driven rain. We I&W under them if we're not replacing and nail a 2x6 down over the top of them if it's going to have a chance of rain on it.

2. Stone chimney flashing details (same idea as #1.)

3. Plumbing and exhaust vents. You can make them water tight but you really have to know what your doing. We'll I&W around them and then drop the jack/boot/vent down then I&W on top and tuck it under the next felt lap.

There are other spots but these are the first that come to mind. 

BTW, for valleys we I&W and weave fiberglass felt through it. Best possible way to apply underlayment in a valley detail.


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## MGP Roofing

We'll do it a section at a time, if we do leave part unfinished we tarp it if we can't watertight it with the shingles. Our reroofs usually need new plywood as well as we're replacing longrun steel/tile/cedar/decra etc that usually are laid on battens direct over the rafters. Not many shingle to shingle reroofs here, the few we do are because of install errors-3 tab in high wind areas, stapled on shingles, EG nails in sea spray areas, and such silly things as the use of DPC for flashings like on the last one we did, 40yr shingles, 10yr flashings and nails!


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## Ridgewalker

The question is can you make a roof watertight ? the answer is yes. But you must consider were your from. and how strong the storms are come in. That is were experiance comes to play a good contractor will have it down to a science. The bad or inexperianced contractor will suffer a few times untill they adapt. In storm country you might have to spend alot of time money get your roof weathertight. Were I am at not as much. Tear off and finish is the safest But if you must leave a felted house weathertight for a while make sure you caculated in your bid. 
Us west coast roofers are lucky never rains in summer Nov. is when we start looking at the forecast.


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## KEVinKYroofs

*Felt will stop leak*

ive been in the field for over 15 yrs and yes Felt will stop it from leaking NOTE if properly installed But however everyone takes shortcuts My crew does every felt job as if it may storm any second Penetrations shouldnt be a problem nor chimneys if you have a foreman or crew who has extensive knowledge so the answer is YES felt will stop a roof from leaking for sure !!! Kevin In KY:thumbup:


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## Grumpy

A dry in is not dry, plain and simple.


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## Slyfox

Lol.


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## waverider

roofing contractor for over 30yrs mostly tile , hawaii/ mainland if your underlayment dosent keep the roof watertight then your not doing your job right, underlayment is the main roof protection. The tile or what have you is a ultraviolet protector, so i say yes you can dry-in & stick with rain in the forcast,,
we all; know the cardinal rule """" NEVER LEAVE A ROOF OPEN OVER NIGHT""


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## FriscoBlue

WOW,

I disagree the underlayment is the waterproofing.

When I complete my Slate roof, if the water reaches the felt I have a problem!!!

The Slate and the Copper Flashing are my water proofing.


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## waverider

FriscoBlue said:


> WOW,
> 
> I disagree the underlayment is the waterproofing.
> 
> When I complete my Slate roof, if the water reaches the felt I have a problem!!!
> 
> The Slate and the Copper Flashing are my water proofing.


 yes but your slate roof sweats then what you do if your underlayment is not right, and lets not forget that your puting slate on @ what 8-10 inches to the weather just like shingles plenty headlap and side lap nothing like installing concrete or clay tile, so when in stalling slate your underlayment isnt as important as the underlayment under a concrete roof. And yes ive done slate jobs before ........... no big deal......


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## FriscoBlue

For the Record: my underlayment is done right. 

However as I stated earlier it is not my waterproofing!!

I have worked on Slate roofs 100 + years old, when you remove a broken slate all you see is wood and dust.

However when you replace the broken and missing slate. The roof is again water tight.

No ice and water , no paper!!

just Slate and Flashing.


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## Mr Roofer

The short answer is *YES.*

This is how the world goes round folks.

If you can't dry in a roof with underlay, I don't want you on my roof, that's for sure!

I'm not saying it should be substituted for good roofing practice, but there are certainly instances where it becomes neccesary, so you had better know how to do it, for when one of those instances happens to come up .

Specifically with tile, I don't reallistically know of any other way. And again, specifically with tile, if you can't dry in a roof with underlay, you shouldn't be up there.

This became a longer answer than I would have liked.nline2long:


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## yanceyman1

FriscoBlue said:


> For the Record: my underlayment is done right.
> 
> However as I stated earlier it is not my waterproofing!!
> 
> I have worked on Slate roofs 100 + years old, when you remove a broken slate all you see is wood and dust.
> 
> However when you replace the broken and missing slate. The roof is again water tight.
> 
> No ice and water , no paper!!
> 
> just Slate and Flashing.


FriscoBlue,

I'm sorry, Sir, but your answer is only partially correct. It is a weel known industry fact that slate is NOT waterproof. 1 to 3% of surface rainwater sweats through ALL slate after complete water retention. Ask your rep. Now you may have repaired 100+ year old jobs with no damage, but these would be the exception and not the norm. The reason behind this is usually due to the fact that slate is applied over solid board sheeting rather than plywood. thus able to withstand leaks without dryrot. Not to mention the fact that copper flashing sweats at an enormous rate. So if your underlayment is not carrying of this water you will have dryrot around all your flashing detials. SO, I submit that YES, your underlayment MUST be watertight! End of story.


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## waverider

yanceyman1 said:


> FriscoBlue,
> 
> I'm sorry, Sir, but your answer is only partially correct. It is a weel known industry fact that slate is NOT waterproof. 1 to 3% of surface rainwater sweats through ALL slate after complete water retention. Ask your rep. Now you may have repaired 100+ year old jobs with no damage, but these would be the exception and not the norm. The reason behind this is usually due to the fact that slate is applied over solid board sheeting rather than plywood. thus able to withstand leaks without dryrot. Not to mention the fact that copper flashing sweats at an enormous rate. So if your underlayment is not carrying of this water you will have dryrot around all your flashing detials. SO, I submit that YES, your underlayment MUST be watertight! End of story.


:thumbup:


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## vtroofing

Deck Armor. Leave it many nights in a row in rain no issues. Ranches and walk-ables may be the exception to the rule, but if its a ranch its easily done in a day. The bigger, even cut up steep ones no issues. Did a 100 square tear off, Deck Armored no weaving of underlayment on valleys, open with Weather Watch and no leaks. That was June of this year, rained mostly everyday not one leak. Felt, probably would have dried, shrunk and blown off.


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## FriscoBlue

Again I disagree,

Upon completing a slate roof it has potentially thousands of nails through the felt.

I believe my Slate roof is watertight, underlayment or not!!

That is the way I was taught in Europe on site and at trade college.
There are Slate roofs on some structures hundreds of years old, Historic buildings. There is no rot on these structures, until I see it I will not believe Slate roofs leak and depend on Underlayment!!

Out here in California a lot of the Roofing companies install a full layer of Ice and water on Plywood.

Now that will be a huge problem in a few years time!!!

I have been roofing 31 years, Love the Forum, I have learning every time I log on!!

Merry Christmas Guys,


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## FriscoBlue

_Just found another Slate roofer here in the USA agres with what I was taught in Europe. Joseph jenkins is known as an expert in Slate Roof instal;lations. Slate roof Bible etc_

_[Author's postscript: It should also be noted that peel and stick underlayments, and virtually all underlayments have a very short life expectancy relative to stone roofing. The idea that such underlayments will benefit a slate roof over the life of the roof is just incorrect. The underlayment will dry out, crack, disintegrate, turn to dust and fail long before the roof itself has reached its end. For some reason, this is a hard concept for many in the roofing and design industries to understand. If the underlayment material will fail long before the roofing fails, and the roofing will continue to service the building as a water-tight barrier for decades despite the lack of effective underlayment, then that should be seen as abundant proof that the underlayment's purpose is to keep the water out of the building until the final roofing is installed. Of course, this is assuming the slate roof is installed correctly with adequate headlaps, sidelaps, slope, and flashings. If the installation is poor, then the peel and stick underlayment may hide leaks long enough for the contractor to get paid and disappear. At the risk of being too candid, I must say that this may be the biggest reason why peel and stick underlayments are so popular today.]_​


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## RooferJim

Slate Roofs in the Boston area , even the ones that are one hundred years old almost always have a heavy felt underlayment. Tile roofing is even more important to have a good underlayment since it has no real headlap. shingle roofs are water sheding systems and are suseptable to wind driven rain. underlayment is an important part of the system as is good flashing and proper fastening. Nails through you felt has no bearing on it unless they rip the felt. How do you apply your felt ? nails right ? don't believe everything you read from Jenkins many real slaters find a lot of flaws with his methods. common sence is not always common.
RooferJim
www.jbennetteroofing.com


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## FriscoBlue

RooferJim said:


> Slate Roofs in the Boston area , even the ones that are one hundred years old almost always have a heavy felt underlayment. Tile roofing is even more important to have a good underlayment since it has no real headlap. shingle roofs are water sheding systems and are suseptable to wind driven rain. underlayment is an important part of the system as is good flashing and proper fastening. Nails through you felt has no bearing on it unless they rip the felt. How do you apply your felt ? nails right ? don't believe everything you read from Jenkins many real slaters find a lot of flaws with his methods. common sence is not always common.
> RooferJim
> www.jbennetteroofing.com


Hi Roofer Jim,

Agreed on the nails through the felt, however a plastic cap nail is driven home.

The heavy felt in the Boston area how long will it last? Will the Slate roof need to be replaced after the heavy felt is gone.

NO, the Slate roof will continue to last for many years after the felt has deterioted.

Guys, I am not against a good paper job, we leave nrew construction jobs felted in the winter without any leaks. 

I would never rely on it as I know when it has reached the end of its life, the Slate will continue to be a waterproof roof.

Happy Holidays guys


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## English Roofer

Here in the U.K we use Tyvec breathable under felt to first make the roof water tight,it comes in a 1 meter(37") wide roll and is tacked or nailed on it is laid with a 6" head lap, the battens (2" x 1 ")are nailed in to the rafters and then the slates are nailed to the battens,the slate nails do not penetrate the felt, the slates don't sweat because of the breathable felt.
I use the felt to water tight the roof first,if i see any holes or rips then i repair these with mastic which will keep the roof dry till the roof is slated in, the felt in my opinion is just a secondry guard to the roof being water tight, the slates are the first.
I too have seen old slate roofs that don't sweat or leak, under layment was only used in this country from the late 50;s onwards, in fact my own roof has no under layment on it and doesn't leak, its the original roof from the 30's
Cheers
Dave


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## yanceyman1

*Back in 1970's*



FriscoBlue said:


> _Just found another Slate roofer here in the USA agres with what I was taught in Europe. Joseph jenkins is known as an expert in Slate Roof instal;lations. Slate roof Bible etc_
> 
> _[Author's postscript: It should also be noted that peel and stick underlayments, and virtually all underlayments have a very short life expectancy relative to stone roofing. The idea that such underlayments will benefit a slate roof over the life of the roof is just incorrect. The underlayment will dry out, crack, disintegrate, turn to dust and fail long before the roof itself has reached its end. For some reason, this is a hard concept for many in the roofing and design industries to understand. If the underlayment material will fail long before the roofing fails, and the roofing will continue to service the building as a water-tight barrier for decades despite the lack of effective underlayment, then that should be seen as abundant proof that the underlayment's purpose is to keep the water out of the building until the final roofing is installed. Of course, this is assuming the slate roof is installed correctly with adequate headlaps, sidelaps, slope, and flashings. If the installation is poor, then the peel and stick underlayment may hide leaks long enough for the contractor to get paid and disappear. At the risk of being too candid, I must say that this may be the biggest reason why peel and stick underlayments are so popular today.]_​


First let me say that when this book was FIRST published, concrete tile was being hung on SKIP sheething. Of course, we all know how that one worked out! My point is this is 2011. Times have changed. The new underlayments don't, ( ”dry up and blow away”). These are from the Plastic family, not ragfelt. And we all know how long plastics have survived in landfills. Not that they will outlast slate, but they nolonger have the 25 yr. life they used to.
But wait, I must tell all of the slate and other journeymen roofers who have responded, THANK YOU. You are the kind of guys I would like to roof with. Take pride in your work and teach those ethics to the younger generation coming up behind you. Roofing my not be the nobleist of tne trades, but when we show up during a bad storm and water is leaking in everywhere....the lowly roofer becomes KING.!! So keep it up and thanks.
Now on to my real subject. When i started this thread, it was in reference to an 80 sq. CONCRETE tile job. So i don't want to drift to far from that subject. If you could, or rather, if you have the time, FriscoBlue and Waverunner, please read my thread on the newer Sharkskin undelayment. I would be very interested in your veiws. 
Once again, Thanks to all & to all a Merry Xmas


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## FriscoBlue

Hi Yanceyman1,

Sorry, I was the one who made the post drift off topic.

I have not laid a Concrete tile in 25 years, back when I did it was Marley major and Redland Stonewald, I think that is what they called them in Europe? 

We used a heavy felt underneath and two layers of torch on in the valleys, low budget type of homes. We also used to nail a vertical batten in the rafter and then attach the Horozontal battens, this helped the water drain, opposed to what I have saw here nail the horozontol battens to the felt.

I have installed quite a few clay tile projects here in the USA, minimum underlayment has been two layers of 30LB felt, I have also used GAF Underoof 2 peel and stick, Grace and Ice water shield and Storm guard

I have not used Sharkskin nor will I after reading your post, thank you for the education on that. 

I am a traditional guy and it takes a lot to switch me from the 30LB felt, I install two layers on every Slate and Tile job job.

I will keep reading the forum to find out how those synthetics are holding up. LOL

I do have a computer and not a typewriter so I can have a change of heart!! LOL LOL

To all you fine roofers on the Forum, thank you for the education, we can all help each othe to be better Roofing Contractors!!

Cheers for now.


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## English Roofer

I have not laid a Concrete tile in 25 years, back when I did it was Marley major and Redland Stonewald, I think that is what they called them in Europe? 

We still use those tiles today, especially the Marley Modern tile, this is basically a concrete slate.
Cheers
Dave


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## vtroofing

Nobody commented on the Deck Armor, hmmm.

English- I just saw for the first time Tyvex for the roof in a local lumberyard.
Seemed like it might be slippery? Deck armor seems less than slippery, quite a bit thicker without being slippery- 

I get tried and true felt paper- but up here felt is rare these days. Cost for 30# felt is about $20 a roll / 5 rolls ($100) to get to a full roll Deck Armor at $160 a 10 SQ. roll and the wind and the sun compared to the speed of installation explains the change. 

Just my opinion, but curious to see others taking the same steps.


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## FriscoBlue

YIKES.

I am paying $26.50 + 9.25% tax for a roll of 30 LB delivered to the roof top.

California prices??

How is this Deck Armour? Good for Slate Roofing?

I have saw it at ABC supply, I will check it out.

All the best for 2011.

Cheers


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## apehangeralfy

With the inspection requirement in FL I peel-n-stick everything... in the wet season you can expect a sever thunderstorm almost daily and you can shingle until you have the roof entirely torn off, dried in and metaled then you get to sit and wait for the inspector before you can start re-roofing... Felt paper has to be nailed to Hurricane Mitigation specs, 6" on laps and 1' in field, takes forever eve with a gun so the difference in labor I can install a full peel-n-stick at the same cost and have never had one leak at the dry-in stage even in 4" of rain an hour storms, so I am sure they will not leak when shingled properly....


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## Dan Gravelle

*shingles or flat*

if its a flat roof you better only bite off what you think you can chew in a day. but if your a real roofer...and you work on shingle roofs, lol its better to only rip off what you can do, but it would be safe to leave it preped, but hope theres no winds to rip off that paper. Myy advice...if you ripped alot, then cover alot even if you have to work later. 

No offense ment to flatroofers its an inside beetween me and my cuz.


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## daviddeschaine

*The Roofing Materials Do The Work - Underlayment’s Questionable!*

We strip off roofs everyday, and we see 20 year old roofs with no underlayments, and they have never had a leak - Even Up Here In Maine!

*We use to claim 10 years ago that Grace Ice & Water shield helped against Ice dams, and it does not!*

Shingle Do The Work or what ever roofing materials that are facing the elements - *Underlayment’s Are Questionable!*


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## RooferJim

Dave I totally disagree with you. If your Grace I&W didnt work for you then I would bet your guys "or maybee subs" didnt put in on correctly. Some Free Roofing 101. Fist of all a shingled roof system is a water sheding system it is not an impermeable water barrier like a membrane roof is, if water backs up over bare sheathing due to an ice dam or wind driven rain in a north east storm it can and will leak. If you use Grace its important to follow what they say, minimum 6' up , past the warm line wall by 3' . You also have to have it under "yes under" the drip edge. We turn it over the facia to seal the joint at the bottom of the sheathing. This is a critical detail and is a Grace spec. Never an issue with this way.

RooferJim
www.jbennetteroofing.com


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## yanceyman1

daviddeschaine said:


> We strip off roofs everyday, and we see 20 year old roofs with no underlayments, and they have never had a leak - Even Up Here In Maine!
> 
> *We use to claim 10 years ago that Grace Ice & Water shield helped against Ice dams, and it does not!*
> 
> Shingle Do The Work or what ever roofing materials that are facing the elements - *Underlayment’s Are Questionable!*


Dave, I totally disagree with you! Have you done much concrete tile roofing? From reading your post, I would say, No. I concider myself a Master Craftsman when it comes to tile roofing, with over 30 yrs. applying and teaching. And I have never installed a tile roof without a good watertight membrane below it. That means, turning up the walls 4 to 6 inches, corner cutting all vertical to horz connecting planes, (so when your finished you only have a small pinhole), double jacking all pipes, (one woven into the base and a top jack), skylights and chimneys get the same turn up and corner cuts, etc... 
I will say this one more time, please all of you journeymen roofers out there posting on this forum, try and remember that there are some apprentice roofers and novice homeowners who read these posts, so try your best not to throw out a "blanket" statement pro-porting to cover ALL underlayments and their various applications.
After saying all of that, let me state an industry wide, field tested, manufacture specification, laboratory tested FACT... concrete tile is NOT waterproof. According to EVERY major concrete tile manufacturer, after a tile has absorbed its own weight in rainwater, a percentage of all of the following rainwater will run right through the tile. Well, maybe not "run", but rather drip. This percentage varies from 2% to 6%. They have determined this using many different tests and they ALL agree on this fact. Why do you think that all of the tile manufactures specification and installation guidelines REQUIRE a waterproof membrane under the tile?
So, Dave, I ask you, let's say you are the roofing contractor on a 250 house tract, with tile roofs. Do you go in under the assuption that you will be able to keep up with the with the carpenters and ahead of the rockers and painters, by starting one house and closing it up completly before moving to the next? In a perfect world maybe. But its never going to happen here on earth. I manageed a 200 house tract once, ( a nightmare!!). But at any one time I had 10 houses that were based and batted, 15 based /batted and loaded with tile, 10 that were half done, 5 that were complete except for the mortor on the bullnoses... you get my point. You see the roofs have to be watertight for the rockers and painters to start, but on the two story houses you must leave at least a 4 ft. wolkway for the exterior painters and/or stucco guys. But yet, the tile weight has to be on the roof for x amount of time before stucco can be applied. To prevent cracks due to settleing if the tile weight is applied after the stucco is finished. Blah, Blah
You get the idea now, right, Dave? 
In parting, if your underlayment is not watertight and, heaven forbid, you have a leak problem, what do you think the manufactures rep is going to say about the home owners warranty? VOID! It then becomes an installation issue, rather than a material failure issue. Who do you think is then going to be liable for the water damage? R I G H T !
Thanks for all of the imput, good forum guys!!:thumbup:


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## daviddeschaine

*Great Information Thanks!*

I sell over 2000 - 3000 rolls of Grace Every Year - But I really don't have any confidence with Grace to help if a home owner has an Ice dam - What Do You Guys Think!

Has anyone had a leak after installing Ice & water shield, and then a home owner has an Ice dam?











yanceyman1 said:


> Dave, I totally disagree with you! Have you done much concrete tile roofing? From reading your post, I would say, No. I concider myself a Master Craftsman when it comes to tile roofing, with over 30 yrs. applying and teaching. And I have never installed a tile roof without a good watertight membrane below it. That means, turning up the walls 4 to 6 inches, corner cutting all vertical to horz connecting planes, (so when your finished you only have a small pinhole), double jacking all pipes, (one woven into the base and a top jack), skylights and chimneys get the same turn up and corner cuts, etc...
> I will say this one more time, please all of you journeymen roofers out there posting on this forum, try and remember that there are some apprentice roofers and novice homeowners who read these posts, so try your best not to throw out a "blanket" statement pro-porting to cover ALL underlayments and their various applications.
> After saying all of that, let me state an industry wide, field tested, manufacture specification, laboratory tested FACT... concrete tile is NOT waterproof. According to EVERY major concrete tile manufacturer, after a tile has absorbed its own weight in rainwater, a percentage of all of the following rainwater will run right through the tile. Well, maybe not "run", but rather drip. This percentage varies from 2% to 6%. They have determined this using many different tests and they ALL agree on this fact. Why do you think that all of the tile manufactures specification and installation guidelines REQUIRE a waterproof membrane under the tile?
> So, Dave, I ask you, let's say you are the roofing contractor on a 250 house tract, with tile roofs. Do you go in under the assuption that you will be able to keep up with the with the carpenters and ahead of the rockers and painters, by starting one house and closing it up completly before moving to the next? In a perfect world maybe. But its never going to happen here on earth. I manageed a 200 house tract once, ( a nightmare!!). But at any one time I had 10 houses that were based and batted, 15 based /batted and loaded with tile, 10 that were half done, 5 that were complete except for the mortor on the bullnoses... you get my point. You see the roofs have to be watertight for the rockers and painters to start, but on the two story houses you must leave at least a 4 ft. wolkway for the exterior painters and/or stucco guys. But yet, the tile weight has to be on the roof for x amount of time before stucco can be applied. To prevent cracks due to settleing if the tile weight is applied after the stucco is finished. Blah, Blah
> You get the idea now, right, Dave?
> In parting, if your underlayment is not watertight and, heaven forbid, you have a leak problem, what do you think the manufactures rep is going to say about the home owners warranty? VOID! It then becomes an installation issue, rather than a material failure issue. Who do you think is then going to be liable for the water damage?  R I G H T !
> Thanks for all of the imput, good forum guys!!:thumbup:


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## Slyfox

Grace or any other type of ice guard is/are not an ice dam prevention,
they are designed to help minimize the damage caused by ice dams.

Yes I have seen roof leaks in valley's, along walls ans on eaves that are covered with ice & water shield.
Usually it's caused by poorly placed fasteners or back water laps.

Ventilation, Insulation and Properly sealed off attic/crawl spaces are ice dam preventions.


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## vtroofing

Ice issues should be part of the roofing package, proper insulation and ventilation. Those pics are common problems seen in snowy areas. 

Ranches with common overhang trusses with 2x4 top cord have the same problems but as Professional Roofing Contractors it is our job to inform HO's the proper ventilation techniques along with enough insulation to make a difference. 

I & W is BACK-UP. No pun intended.


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## Perden Construction

Yes it will. We dry-in right, use ice and water in all valleys, around chimneys, along walls, and around all penetrations. We normally install Deck Armor but sometimes use a 30lb felt. When we are getting thunderstorms every evening in the summer and fronts other times of the year we get rain on roofs all the time that are dried in, no shingles ran yet and we don't have any problems. The way we do the roofs here in FL with the codes and inspections that we have to get pretty much makes us tear a roof off and dry in for the day. Say we have a 4 man crew and get on a 40 sq house. We will tear off down to the deck, replace wood, re-nail all decking 6"oc on each truss, then dry the roof in. Depending on the job we may do that in a day or it may take two. Then the inspector comes and checks our decking in 3 random spots and checks the dry-in nail patterns. Only then can we start shingling. I can only tear off sections and shingle them up right afterwards if it is a townhome, commercial, or it's out of city limits and I can get an affadavit.


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## MGP Roofing

Here, just about all tile roofs over 30 years old have no underlay, and many newer ones don't either. Only times its mandatory here is in high wind areas and roofs under 20 degree pitch, most clay tiles require it as well due to not fitting together as neatly as concrete tile. 
This is the inside of a 50 year old roof I salvaged the tile off of early this week. No sign of any water having got near the battens or ceiling. One tile had a pinhole leak, and 2 broken, it was only replaced due to major alterations and a inability to match the tile.


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## FriscoBlue

:thumbup::thumbup::thumbup::thumbup:

Yea, that is what I have saw over the years also.

Thanks for sharing


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## mindfield

Rain??? What Rain??? It's not SUPPOSED to rain!!! OMG... I gotta GO!!!


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## yanceyman1

MGP Roofing and Frisco blue, I'm very disappointed in the information you've decided to share here. All I can say is this.. can you produce any manufacturers specifications from ANY tile manufacturer on the planet that doesn't, REQUIRE, not recommend, a watertight membrane under their product? You are right about a Hood roofer from the 1940's could apply tile over skip sheeting with a minimum 4" headlap. But let me assure you that if you were try that today, you would void any manufacturers warranty that the homeowner was entitled to and you'd be out of business in no time. So let's please stick to time relevant, manufacturers specifications backed installation practices. All of mankind has changed since the 1940's.


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## MGP Roofing

Here's the spec for one of our most popular tile manufacturers, read pages 10 & 11 of this: http://www.monier.com.au/Professional/ArchitecturalManual/Downloads/CSR_Roofing_ArchManual_S3.pdf


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## FriscoBlue

Yanceman, Relax!
We share opinions on here, we do not always agree!!!!

A slate Roof does not require underlayment to keep the roof watertight!!!!!!!
of course i always install a good watertight underlayment prior to installing the Slate !! However when that underlayment wears out in the next 50 to 60 years, my slate roof with Copper flashings will be a watertight roof for many more years!!
That is right it will not leak!!!!!


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## yanceyman1

OK guys...I'll agree that we do share opinions here. And I apologize if I seemed to present mine in a forceful manner. That was never my intention. Although I started this forum years ago as a way to get answers about a synthetic underlayment I was having problems with, it morphed many times and became educational on many different subjects. So thanks to all who shared. Although I have taught the Apprenticeship program for the great state of California since 1989 and have over 30 years invested in this roofing industry I love so much, only a foolish man thinks he knows everything. And, well gentlemen, I'm no fool. LOL. Thank you all for taking the time to share. May all your jobs have 15% profit, your compressor always start on the first pull and your air hoses never leak!


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## roofermann

dougger222 said:


> Yes you can HOWEVER there are certain items that are tougher to I&W/Felt dry.
> 
> 1. Step flashing details. If the tins are lifted up which they should be to allow new underlayments under them they could bring in wind driven rain. We I&W under them if we're not replacing and nail a 2x6 down over the top of them if it's going to have a chance of rain on it.
> 
> 2. Stone chimney flashing details (same idea as #1.)
> 
> 3. Plumbing and exhaust vents. You can make them water tight but you really have to know what your doing. We'll I&W around them and then drop the jack/boot/vent down then I&W on top and tuck it under the next felt lap.
> 
> There are other spots but these are the first that come to mind.
> 
> BTW, for valleys we I&W and weave fiberglass felt through it. Best possible way to apply underlayment in a valley detail.


We do it similar but tarp it as well. Summer T-storms here in Va can be fierce.:thumbup:


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## slateandtile

To be honest I don't really care if the regulations say you don't need to put a roof underlay on a roof over a certain pitch. I would always install this and take the time in doing so to make sure it was watertight. I think if there are products available that will improve the job you do you should be using them.
This may lose me work because my prices will be higher than someone who is willing to do the minimum required.
Roofers have a bad reputation for cutting corners and this is one of the things I hate about the trade.
We need to educate the customer in what they are paying for and why you should use it. 

Slate and Tile Roofing


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## Pie in the Sky

Slate and TIle do not need underlayments.. Ive looked at alot of 100 year old slate roof from below and the underlayment is Dust.. Most slaters who work in ice-damming areas just shrink the exposure at the eaves.. seems to work.


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## slateandtile

My point was that you should install anything that is available to improve the job you do - an underlay improves the job. If you have a roof that has broken slate/tile and it has an underlay it will stay watertight while you get the problem fixed. Also during the installation you can keep the building watertight while you do the work. With no underlay you have an instant problem.
We all know these problems occur - so install an underlay if you can.


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## RooferJim

There is never a good argument to downplay underlayment. People that try to are usually the hacks of the trade.

RooferJim
jbennetteroofing.com


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## Grumpy

On a slate roof, some 30# really won't add much to the cost, certainly less than a square of good American slate. 

I was always under the impression that the underlayment is what kept the water out of most tile roofs, excluding slate. I wouldn't dare dream of installing a spanish type tile roof without a great premium underlayment!


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