IMetal roofing underlaymets

Carlise WIP300 vs. Grace HT vs. OwnensCorning Weatherloock Special Tile & Metal

Any failures?

I kind of gave up on figuring out where the seam goes woody.....I guess to do it right you'd have lap it across the valley and not install it vertically, or with the valley.

Which means of course with the laps included, you'end up using a TON of the stuff to make the 6' Min,

Twil said;I came upon a new twist in the Excessive Ice & Water Shield Syndrome (EI-EI-O-WS Syndrome) last week:

6 ft. of it in the valleys. Yes a homeowner asked me to match the others guys' specs.......neither of whom cared to address the blocked soffits.

6' is a strange number to spec. If you run I&W up the middle of the valley and then lap another roll on each side, you'd be about 4 1/2' out of the valley. Of course if you put your lap seam right down the middle of valley, you get your 6' with no cutting. ;)

I came upon a new twist in the Excessive Ice & Water Shield Syndrome (EI-EI-O-WS Syndrome) last week:

6 ft. of it in the valleys. Yes a homeowner asked me to match the others guys' specs.......neither of whom cared to address the blocked soffits.

So of course I can either try to convince him that the other guys are CLUELESS, but since I just SHOWED him that, I was not sure if he would believe what I was saying, since he had just been SHOWN that the others were CLUELESS.

Although I WONDER sometimes how we got here, and sometimes I am SHOWN just how we got here.

ROOFING: Where the tail wags the dog

We usually use a SBS SA underlayment our preference is Polyglass a little more expensive but worth the well worth the price. Min hole penetration on the dry in.

i just did a metal roof.and just used 30 pound.and vented the ridge.you don't need high tech underlayment.

OS/Wywoody...Some good stuff....

The 'sap' story is my understanding, as well....and yes, the advent of solid sheathing had a detrimental effect on shakes.

The reactionary disposision of gov't agencies affects us in all sorts of ways....We have a nearby county which requires I&W on the entire roof, no-matter what....Simply because the predominent workforce cannot install roofs without it and not have them leak!

I use I&W for three things, one is for its' intended use and in my climate that's jobs above 1500' elevation. The second is for roofs 5/12 or lower and the third is for repairs where the material cost is such a small portion of the total that it makes sense to upgrade to the best underlayment available.

When I first started it was in SLC and everything we did under 8/12 (in the 70's that was almost everythiing)used an underlayment of 30lb followed by vertical lath that was then floodcoated with hot asphalt. The only penetrations through the underlayment were through the lath and elevated above any potential water flow. Because the higher end homes there tended to be higher on the 'bench of the front range' or in the mountains, it was not unusual for the North side of a house to be snowed in for months during the Winter and, underlayment had to be the only roof while interior work proceeded.

I retain that respect for the integrity of the underlayment. I believe if you're going to spend the money for the underlayment you put it on right, you seal all holes in it, you take it up walls and make sure it is properly lapped by the wall covering and minimize penetrations.

Where I live now, we had one big legendary storm in 1962 called the Columbus Day storm. The county I live in had major damage from wood shake/shingle blowoff. Once a small portion of the roof blew off, it allowed the wind to push up from under the spaced sheeting and greatly increase the amount of damage. The reaction was to make plywood with felt required for wood roofs. This, of course, greatly shortened the lifespan of wood roofs and the result was a greater acceptance of tile here than just across the river in Portland, so I'm grateful for the building department's ignorance.

You have no idea how many thousands of squares of shingles we installed in the 50's 60's and 70's without felt. In fact, at one time there was a "shortage' of felt and you could only get in so many rolls per semi-truck load, which was supposedly enough to install 2 rolls on the bottom of the roof to satisfy the FHA requirements.

At one time, I remember the shingle rep telling us that the "reason" for felts used to be that they used 1 x lumber for roof decking and that the sap from the knots would attack the backs of the shingles so you put the felt down to "protect" the shingles from the sap. Like Tinner said though, if they could sell felt with all of their shingles, they could increase their volume by 10% It is quite a program.

A lot to think about eh. A big reason for the "failure" of the roofs today is the lack of proper ventilation. THAT, you can take to the bank!

"Felt beneath asphalt shingles was originally intended to be a divorcing layer, Seperating the asphalt shingles from the wood substrate." And if you were popping lines, you could do it over a crack.

'If you can't roof it, use I&W, then felt it with a few layers and at least keep the home dry until the warranty is over' is the 'Rule of the Day' for the last several years.

I never even consider subbing work to any person, or any company whose owner tells me "Our call backs dropped/slowed/stopped/decreased, or similar, when we started using I&W on everything."

Amen Robert.

92' is when I came across the underlayment dependency craze, here in Colorado....Local municipalities were requiring 30# over old comp when re-covering....The best one, was when I noticed an outfit installing I&W over old T-lok, then another layer of comp....O - M - G!....

When i started roofing in British Columbia in 1981 we did not felt any shingle roofs in, shingles applied over bare plywood done that way for years.Shakes got felt 18 in rolls,felt is just a temporary dry in for new construction or reroofing is not part of the roofing system if water gets to the nails they will rust away and eventualy leak.Ice and water shield and felt paper are additional sources of income for the manufactures,everything has been added to increase thier profit margins.Because the state of florida thinks covering a house in ice and water shield is a roof dont make it so.When thousands of nails penetrate the substrate it will not withstand longterm exposure to water it will leak! :woohoo:

Felt beneath asphalt shingles was originally intended to be a divorcing layer, Seperating the asphalt shingles from the wood substrate.

Contrary to popular belief; Not an intregal part of any water-shedding mechanism.

However, as we all know, (just take a look at our freedoms, gov't's role, etc.....), time & popular perception, takes a toll on realities....

TomB Said: Do you know what the actual purpose of felt under shingles is for?

Yup I know. It doesn't matter what anyone thinks or says, if you are in the business, you follow the manufacturers instructions. They are written on the shingle packages or you can go to the websites.

B) :) :) B) Deep Down In Florida Where The Sun Shines Damn Near Every Day

Do you know what the actual purpose of felt under shingles is for?

Underlayments have been around and used for over 100years The most common shingle underpayment in North America for the last 100 years has been 15 or 30 pound asphalt felt. These products have performed well when properly secured. Failures from one piece and plastic caps have led the insurance company's push for peel and stick. Miami Dade testing proved that the old nail and tin cap standard tested higher than most peel and stick products. This method has always been the standard. If your going to use underlayments do it the proper way. B) :) :) B) Deep Down In Florida Where The Sun Shines Damn Near Every Day