Roofing Underlayment For New Roof South Florida


#1

Hello,

I live in S. Fla. and need a new roof. Been doing my research on underlayments. My current roof could be original from 1969. I bought house 6 years ago.
It has a white roof but I am thinking about going grey for a modern look plus the white gets so dirty.

I do have a few questions……

  1. I am interested in the Layfast TU 43, (if available here), or another similar synthetic and would like to know how it can be double layered applied? When you nail down the 1st layer do you put anything in between or do you just nail down the 2nd layer?

If you do nail down the 2nd layer right on top, what benefit is that?
Wont too many nails be concerning for leaks from far more nails than traditional 30/90 hot mop?

Isn’t that also like putting 2 band aids, right on top of each other, over the same cut? Doesn’t mean its better in long run right?

2). My roofer, very well respected, been in business 30 years, never did synthetic before. His knowledge and experience is strictly 30/90 hot mop. For that matter, I got 8 different quotes, everybody recommended 30/90 hot mop. He is open to doing synthetic but am a little worried it may not turn out as good with lack of experience using synthetic.

After all, much like AC installation, the brand isn’t as important as who does the installation and how good the installation is.

3). What about a double layer of #40 or #43 felt, so nail 1st layer than hot mop 2nd layer? Is that a decent proposition for possibly better lasting underlayment than 30/90?

4). Since I am probably going a dark concrete tile, wouldnt added heat from tile possible cause a faster degradation of the felt over the synthetic?

Do we even have 10 years++ data on synthetic to judge?

These crazy high warranties offered on Synthetic I think is a BS Marketing ploy, how the heck do they know? Its not like anybody in the company have been using them since 40s or 50s to have any real world data points or experiences. I believe they are nothing more than “fantasy” warranties much like the Chinese Solar panels offering lifetime warranties, then next thing you know many are out of business. So I am not buying these 50 yr warranties on Synthetic. #FakeNews

Also, The warranties are so restricting and the roofing work done by the contractor will be scrutinized severely by the manufacturer that I feel they have easy way “out” from honoring warranty. The other thing that worries me, is the many companies jumping into the synthetic underlayment business just like the Chinese solar panel example.

5). Lastly, I also have a flat roof that needs to be done, can I get a few recommendations for making this roof last as long as
possible and more importantly waterproof

I was given the following by 3 different contractors

A. GAF #80 base sheet
GAF Modified #20
1 ply mineral surfaced Cap Sheet

B. #75 Glass base sheet
1 ply of ElastoBase
1 ply of Elastoflex SAV self adhered
1 play of PolyGlass cap sheet SAP self adhered

C. #75 GAF base
#20 GAF Ruberoid Modified
1 layer GAF Mineral Cap Sheet

Thank you for any help you can provide me.


#2

8 different quotes,
Not one suggested Synthetic underlayment for your roof.
Think about it…


#3

Ditto what roof lover said. While I believe synthetics have their place in the market I do not feel they make a good choice for a tile underlayment. While I am not much of a tile guy myself I would prefer a self adhered underlayment on any tile roof I install.


#4

I do understand where you are coming from, but 18 mos ago, I thought my Central Air unit was going out, I had just about the same if not more come out , 8-10, to tell me I needed an entirely new split system. Throwing my hands up, I had one last guy come in, said
change a part that was $180 , and I still have the AC Unit.

In Miami (I am north of ft lauderdale) they tend to be more updated on the latest methods from what I hear. I’m not saying Synthetic the way to go, but I see/hear more and more doing it.

You may ask why do I get so many contractors when I need something done? Because S. Fla is one of the most shady/corrupt/deceptive places in the U.S. could possibly be #1, anyhow, very rarely do you find honest people. So I look for
some common ideas/estimates on how the job should be performed then decide between top two.


#5

Tile is almost mandatory down here due to the weather. Alum /Metal Roofs really gaining popularity.

Any specific SA brand? Do you first go felt than SA? Or simply SA right on the decking?
Thanks


#6

SA alone is perfect for a tile roof.
No issues with replacement of roof in the future.