SKU: 99275124334

GAF Silicone Mastic, White — 3.5 Gallon Pail

Sale price$94.13 Regular price$104.59
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Description

GAF Silicone Mastic, White — 3.5 Gallon PailGAF Silicone Mastic Sealant, White (3. 5 Gal) Professional grade, thick silicone mastic designed for flashing and detail work. Low odor, fast moisture cure formula adheres strongly to a wide range of roofing substrates. Key Features: High Build Silicone Sealant: Thick consistency for robust coverage on seams, penetrations, and flashing details Easy Application: Low odor and smooth tooling help speed installs on the jobsite Fast Moisture Cure: Cures

GAF Silicone Mastic Sealant, White (3.5 Gal)

Professional-grade, thick silicone mastic designed for flashing and detail work. Low-odor, fast moisture-cure formula adheres strongly to a wide range of roofing substrates.


Key Features:

  • High-Build Silicone Sealant: Thick consistency for robust coverage on seams, penetrations, and flashing details
  • Easy Application: Low odor and smooth tooling help speed installs on the jobsite
  • Fast Moisture Cure: Cures quickly to reduce downtime and return roofs to service faster
  • Strong Multi-Surface Adhesion: Formulated to bond to a variety of common roofing substrates
  • Tested Performance: Meets ASTM D1644, D2697, and D2370 standards

Specifications Table:

Specification Details
Color White
Package Size 3.5 Gallon Pail
Item Weight 42 lb
Standards ASTM D1644; ASTM D2697; ASTM D2370
Manufacturer Number 891402WH
Product Number GAFSM35WH
Category Adhesives, Caulks & Sealants
Description A thick, high-build silicone sealant featuring low odor, easy application, fast moisture cure, and enhanced adhesion to a variety of substrates.

Frequently Asked Questions (FAQ):

Q: What is the color of this silicone mastic?
A: White.


Q: How much product is in the container?
A: 3.5-gallon pail.


Q: What standards does it meet?
A: ASTM D1644, ASTM D2697, and ASTM D2370.


Q: Where is it typically used?
A: For flashing, seams, penetrations, and detail repairs on compatible roofing systems.


Q: Does it have strong odor?
A: No—it's a low-odor formula for easier application.


Sculpted Protection with a Clean, Architectural Finish

This silicone mastic draws a crisp, modern line around roof penetrations and edges, bringing order and polish to functional details. I love the dense, high-build body—it lays down with confidence and dries into a sleek, resilient skin. Use it to frame flashing and seams with a refined, white accent that feels intentional. It’s a quiet essential—performance-forward and luxuriously reliable.


Seal critical roof details with confidence—choose this GAF Silicone Mastic for fast-curing, durable adhesion that lasts.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 99275124334

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4.8 ★★★★★
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kkl
Lexington, US
★★★★★ 5
Very good product
Size: Medium, Color: (001) Black / Black / Pitch Gray
I purchased these to wear inside lowcut slip on casual shoes, I don't particularly like to not wear socks in my shoes for hygienic reasons. Prior to purchasing these socks, all I could find were those made of very light beige hosiery type material , and my slip on shoes would slide around a bit. These are light weight and breathable athletic type material, with a very good gripper strip at the heel. One pair of my slip on casual shoes have a particularly lower cut in the toe area, but the shoe is black and I chose the black color and though I see a hint of the sock there, it matches and does not detract from the look of the casual solid black shoe
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 15, 2026
A
Verified Purchase
Anna Wylda
Charlottesville, US
★★★★★ 5
They stay out! No more sock wads!
Size: Medium, Color: (100) White / White / Mod Gray
Best no show socks ever made!!!!! I've been struggling for 2 years to find ones that actually stay on your foot, even other national brands, and I just became content wearing my sneakers without socks. They ALWAYS slid down into my show & I ended up walking on a wad of sock until I could fix it...or usually just took them off after a couple of tries. Enter Under Armor!!! They a mid weight, but not very thick & still breathable. They work too by actually staying on your foot! Not once have they slid down into my show!! Very comfortable but they could be a little more affordable.
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Reviewed in the United States on August 1, 2025
R
Verified Purchase
Rebekah
Lexington, US
★★★★★ 5
Love!
Size: Large, Color: (100) White / White / Mod Gray
Ive tried so many no show socks but I love these. This is the 3rd set I've bought. They never slip off and the material is thin and breathable. Perfect for working out.
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Reviewed in the United States on March 2, 2026
B
Verified Purchase
Becky
West Palm Beach, US
★★★★★ 5
True no-show socks that don’t slide down!
Size: Medium, Color: (100) White / White / Mod Gray, Size: Medium, Color: (100) White / White / Mod Gray
This is the first pair of no-show socks I’ve tried that actually don’t slide down into my shoes. Trust me… I have tried lots of different pairs and this is the one! They fit perfectly. They’re not too thick and they’re obviously durable because I wash them after each wear, so daily.
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Reviewed in the United States on March 21, 2026
R
Verified Purchase
Raquel Hall
Lexington, US
★★★★★ 4
Great fit but expensive
Size: Medium, Color: (252) Blush Beige / White / Castlerock
These are really great socks. I love them, but they are definitely pricey.
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Reviewed in the United States on March 30, 2026

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