Sharkskin?


#1

Can anyone explain to me the pros/cons of “sharkskin” membrane roofing material compared to tar paper, 15 and 30#. And where should you use 15# and when/where to use 30#. Does it matter which one you use?
And does it matter what roof pitch ?
Thanks,


#2

15 pound can be used on any roof pitch and i will ADD that under a 4/12 pitch you need to install 2 layers of 15 pound not just a 30. AT least thats the way it is where i am at per code. Never heard of sharkskin. I personally use Certainteeds Roofers Select and on 4/12 and under i do a double layer staggered so it will do its jub. Hope that answers your question.


#3

So gtp,
I should use 30# on a 7 on 12 pitch? Would that be better than going with 15# on this roof ?
Thanks for the help


#4

we hardly ever use 15#. it tears way to easy and i have seen guys fall when it ripped out from under there feet. Just use 30#.

Sharkskin (or titanium) is more if you are going to leave the roof exposed for any extended lenght of time.


#5

Sharkskin is great underlayment, while titanium IMHO is just a thick tarp.

I should caution you if you choose to go with sharkskin or other synthetic underlayment - they trap moisture and act as vapor barrier. So you either need a very good attic ventilation or use a breathable underlayment such as GAF deck-armor.

Tar paper or felt is junk - it dries out after 3-5 years. It rips, and now it is very close in price to synthetics - especially if you have to use two layers.


#6

torn off many old roof, perfectly good 30#
under there.
sorry LA.
cannot compute.

gweedo.


#7

[quote=“kourso”]Can anyone explain to me the pros/cons of “sharkskin” membrane roofing material compared to tar paper, 15 and 30#. And where should you use 15# and when/where to use 30#. Does it matter which one you use?
And does it matter what roof pitch ?
Thanks,[/quote]

Sharkskin is one of the  brands of plastic underlayment, they are lighter and stronger than felt paper. The synthetics don't wrinkle up when they get wet so they are great for those situations where the shingles won't be installed immediately.  I just re-built  my roof including new rafters, sheathing and skylights. I used titanium udl 30 which is another brand of synthetic because I worked alone and knew it would take me quite a while to finish the shingling. I really like the titanium, it lays nice and flat and has lots of lines and markings to use for alignment, it also has a great non skid texture.

I added ridge vent just in case the house needs more ventilation with the new roof.
For a normal quick roofing job I’d probably have just used 30 lb felt, it doesn’t really matter what’s on there once the shingles are in place.
The titanium costs about $14 per square, I don’t know what 30 lb felt is selling for now days, but if it is half the price I’d save the money, if it is closer to 75 percent I might go with titanium just because it is lighter to work with and easier to get straight( at least for an amatuer like me) . My previous roof had 30 lb felt and lasted 25 years so don’t worry about it if that’s what you choose.
15 lb felt is very fragile so you will have to take more care if you use it…DaveB


#8

Thanks Guys for all of the great replies.
I will have to decide on whether to use sharkskin or not. I am told it is about $6 more per sq. than 15# tar paper but I want to use 30# so it may even be cheaper than 30#.
I just don’t want to have paper thin tar paper like 15# is.
Can anyone tell me the pros/cons about roof vent boots,should I use the regular plastic boots or make sure to use lead boots. I have had some problems with the old plastic boot seals cracking/splitting.
Let me know?
Thanks again,
Kenny


#9

Plastic, lead, pros and cons to both, the sun breaks down the plastic/neoprene and the squirrells eat the lead.
Take your pick.