New roof recently

   / New roof recently #1  

PAGUY

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Aug 1, 2007
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354
Location
southeastern PA
Tractor
Kubota BX2200, Gravely mower
Not wanting to invade someone else house build I would like to here advice about using TYVEK in place of felt for underlayment. My roofer said it is better than the old way. They did put down drip edge and the ice shield before the 30 yr shingles. They also installed a ridge vent which he said was standard practice now a days. Shingles were installed with 6 nails and rated at 110 mph wind damage.

This company is a family business that has been 3 generations serving the local market and rated highly for their work.

Appreciate any pros and cons. I think I did okay.
 
   / New roof recently #2  
never heard of that one,doesn't mean it isn't right.They are in the business and must guarantee
their work.
 
   / New roof recently #3  
I've never seen a package of shingles that did not list underlayment as part of the installation instructions. So on one hand I'd say if you think they'd ever stand behind any kind of warranty, not having underlayment would probably give them an easy excuse to deny your claim. On the other hand the warranty is almost worthless since it only covers material, which is a small fraction of the cost to replace a roof, so I'd forget about that.
To answer your question it's become common to use more "modern" products like tyvek instead of felt. I've read several published studies that show the only difference between tyvek and felt is price. One was in the Journal of Light Home Construction, the other was from some university in the northwest, maybe oregon but can't remember. So I think there's no harm using Tyvek instead of felt, but it costs more.
Finally I don't see any reason for felt paper on a roof other than to keep it dry before the roof is finished. The felt paper is full of thousands of nail holes, imagining that it is going to provide any additional protection seems to be wishful thinking. I've been told that originally the felt paper was used to allow roofs to achieve a higher fire rating, but I've never found that from any reputable source.
 
   / New roof recently #4  
the basic theory behind "under lay ... felt ... etc" is to prevent the tar in the shingles from being drawn into the wood .. therefore reducing the life span of the shingles ....

shingles are PRO rated ... you get less back as the years go by if you have a claim ....
 
   / New roof recently #5  
PAGUY,

The most common I have seen today is to do the entire roof in ice & water shield and no felt or tyvek.
 
   / New roof recently #6  
A call to your local "Building Inspector "will answer it as per your part of the country.
I built in ct. for years an saw some really strange stuff over the years, never heard of tyveck under shingles...
 
   / New roof recently #7  
I have never seen Tyvek per say, there are products that look similar to Tyvek called roof underlayments. It is quite a bit more expensive than tar paper but much better. The Grace brand is Miami-Dade certified if you install it to their specs. The labor to install roof underlayments is much less than laying paper in a neat and orderly fashion, I choose the underlayment for all my jobs. I have used Grace, Berger and a couple other brands that escape me at the moment.
I'll have to look into the use of Tyvek.
dave
 
   / New roof recently #8  
I would check Tyvek's website, if they reccomend it fine.
 
   / New roof recently #9  
the basic theory behind "under lay ... felt ... etc" is to prevent the tar in the shingles from being drawn into the wood .. therefore reducing the life span of the shingles ....
I think shingle companies have pretty much switched to fiberglass mat for the base layer of shingles. There is still asphalt in the upper layer for water proofing, but it doesn't contact the roof.
 
   / New roof recently
  • Thread Starter
#10  
Using Stimw advice I went to the Tyvek website and found this:

DuPont™ RoofLiner
Premium roof underlayment
DuPont™ RoofLiner premium roof underlayment provides excellent protection against leaks under all types of roof coverings identified by ICC-ES AC48, Section 3.0*. It is trusted protection that can give both you— and homeowners—greater peace of mind.
Made with DuPont™ Elvaloy® AC copolymer
Ideal for sloped (≥2:12) commercial and residential roofs, new construction and re-roofing applications
Class “A” fire rating per ASTM E108
High UV-resistance with up to 6-months UV exposure per ASTMG154
Florida building code approval FL11602-R1
Miami Dade County approval [.pdf]
Approved for use in Canada. Meets Canadian CAN/CSA A220.1 code Intertek #3193611COQ-003A
Superior tear resistance compared to roofing felt for increased durability
Lightweight for easy handling and installation
Better coverage - one 10-square roll replaces about 5 rolls of 30-lb felt
More resistant to mold growth than roofing felt
30-year limited product replacement warranty for builders, general contractors and Professional installers.
Available in 2 sizes: 10-square roll and 4-square roll
» The 10-square roll is 48" x 250' (1.2m x 76.2m) and
contains 1,000ft2 of material (92.9m2)
» The 4-square roll is 48" x 100' (1.2m x 30.5m) and
contains 400ft2 of material (36.6m2)

Proven performance

DuPont™ RoofLiner is made with DuPont™ Elvaloy® AC copolymer, from the family of DuPont polymers used as the basis of the world’s best commercial roofing membranes. DuPont™ Elvaloy® is the brand leader with decades of proven performance in billions of square feet of commercial roofing worldwide.
One 10-square roll vs. 5 rolls


DuPont™ RoofLiner allows for maximum roof coverage and efficient installation—making it easier to install than roofing felt. As a result, there are fewer overlaps, seams and fasteners, which helps reduce both labor and waste.
Superior durability.

In addition to improved water hold-out and better resistance to mold growth, DuPont™ RoofLiner also offers superior tear and UV-resistance when compared to typical roofing felt.

Superior durability combined with higher thermal stability than roofing felt, enables DuPont™ RoofLiner to stand up to the toughest conditions.
* For complete details regarding what roof coverings are identified by ICC-ES AC48, Section 3.0,
 
 
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