Contractor Talk - Professional Construction and Remodeling Forum banner
Cancel
Create thread New Forums

roof underlayment under ss metal roof

2 reading
Jump to Latest
1 - 9 of 9 Posts
T

tonio1985000

· Registered
Joined
·
17 Posts
Discussion starter · #1 ·
Greetings everyone, have a roof question. We have a build we’re doing that has a low sloped roof (1 to a 3 / 12 slope). we are using a standard seam metal roof (mech seam). structure is standard pre-eng wood trusses 24” o.,c. with 5/8” radiant barrier decking. We are in central florida and get a lot of rain, hard rain, sometimes in a short amount of time. So I want a good underlayment that will provide additional water intrusion protection in case rain gets under ribs.
We have 5 underlayment suggestions from our vendor. Anyone ever work with any of these and have any comments and can give me 2 best choices?
Thank you for the knowledge!


Titanium® PSU30 High-Temp Self-Adhered Underlayment
Titanium® PSU30 High-Temp Self-Adhered Underlayment - Owens Corning® Roofing | Owens Corning Roofing

GAF STORMGUARD 2SQ/RL
Protect Roofs with GAF StormGuard Leak Barrier | GAF Roofing

POLYGLASS POLYSTICK MTS PLUS 2SQ/RL
Polystick® MTS Plus | Waterproofing Membrane | Polyglass

ROOFNADO ANCHORDECK PSU 2SQ
Roofnado™ AnchorDeck™ PSU

HydraShell MAX - underlayment
HydraShell MAX - Marco Industries - Roofing Underlayment For All Types Of Roofing
 
#2 ·
I have used Titanium and it works well. Need to install when cooler in the day. If it touches itself, well you cut that piece off and throw it away. And it helps to do shorter pieces, 10', like they recommend. The others have not used .
 
#3 ·
PSU30 handles very much like WR Grace Ice and Watershield. It might even be made by Grace. You'll probably want to order extra unless you are very confident in your ability to install it. It's a real bear for the inexperienced or occasional user.

GAF Stormguard is a pretty good product, but it doesn't stick to the deck 100%. It can be installed "perfectly flat" and will show minor wrinkles after a few days. Wrinkles isn't really the right word, but more like areas where it's apparent that the product isn't fully adhered to the deck. It also will leak in a horizontal direction at the side laps on low slopes. The surface material is great to walk on, but after a rain it's obvious the water collects in between the surface film, which is more like a fabric actually, and the bitumenous main membrane. I use it regularly, but can't recommend on a slope under a 3 pitch.

I am not familiar with the others.

On 2/12 and lower slopes, you really should be double locked mechanical seam with a sealant in the seams. You can use a hot sealant if you're set up for it (or tell your roofer or supplier) or you can use non-curing butyl caulk during the install.
 
#5 ·
Polyglass is our go to underlayment. It’s slightly forgiving when installing so you can get it flat.
After dryin we’ve had plenty of roofs go through the sudden tropical storm like rains, you know those “afternoon” showers with out a leak happening before the final surface was installed.
We’ve used it on 1/4/12 sealed standing seam roofs with no leaks yet.
 
#6 ·
I have been exposed to some different schools of thought on underlayments for standing seam metal roofs. Each type of underlayment is suitable for a particular region and is a function of what is being protected against. Synthetic underlayments generally perform well over time and offer water resistance, especially in areas with heavy rains or snows. The normal felt would be all right if it were to be placed under most metal roofs but may not last as long.
 
#7 ·
I used the Titanium last year, dried in end of May, steel was delivered end of September, install completed in January. No leaks throughout the process

Kind of a b**ch to work with but does it's job well.

Image
 
#8 ·
A&E Exteriors said:
I used the Titanium last year, dried in end of May, steel was delivered end of September, install completed in January. No leaks throughout the process

Kind of a b**ch to work with but does it's job well.

View attachment 579856
Click to expand...
What I use too. If it touches itself you cut it off , theres a reason they say use shorter pieces. lol
 
#9 ·
I've used this stuff before, lets the metal move around on it nicely.
Image
Image

Image

Image

No idea why the pics come out in reverse order??
 
Save
Reply Quote Like Like
1 - 9 of 9 Posts
About this Discussion
8 Replies
8 Participants
Last post:
Dirtywhiteboy
Contractor Talk - Professional Construction and Remodeling Forum
posts
3.6M
members
169K
Since
2003
A forum community dedicated to professional construction and remodeling contractors. Come join the discussion about the industry, trades, safety, projects, finishing, tools, machinery, styles, scales, reviews, accessories, classifieds, and more!
Full Forum Listing
Explore Our Forums
General Discussion Tools & Equipment Business Painting & Finish Work Decks & Fencing