Fixfast SafeSeal®
Class A Butyl strip sealant range engineered for reliable air sealing and weatherproofing across sheeting and cladding applications.
What is Fixfast SafeSeal® Butyl strip sealant?
Fixfast SafeSeal® is a range of Class A butyl strip sealants designed for sheeting and cladding applications to provide long‑lasting weatherproofing and airtight sealing of buildings.
What is the composition of a butyl strip sealant?
Butyl is a general-purpose synthetic rubber and has become a generic name in our industry for strip sealant in roofing applications. Fixfast SafeSeal® is manufactured to a carefully controlled formulation of raw materials, a key component being Polyisobutylene (PIB) Which is a fully saturated polymer that resists weathering and keeps a flexible, slightly tacky feel, so it makes tight, long lasting, air and water-resistant seals. Because it has no reactive double bonds, it’s less prone to slow breakdown in exposed, uncured sealants than unsaturated butyl rubber, which helps with long term performance in roofing and cladding tapes.
SafeSeal is designed in specific shapes and sizes to deliver the right compression and seal profile for different details. Here are some standard applications:
A-3 x 9 x 15
A-4 DIA x 12
A-6 DIA x 8
PB-50
A-5 x 6 x 9.6
A-5 x 6 x 9.6
A-6 DIA x 8
A-8 DIA x 6
A-5 x 6 x 9.6
AUF-6 x 50 x 8
A-5 x 6 x 9.6
A-6 DIA x 8
A-5 x 6 x 9.6
A-3 x 9 x 15
A-6 DIA x 8
A-8 DIA x 6
A-5 x 6 x 9.6
A-3 x 9 x 15
A-6 DIA x 8
A-8 DIA x 6
SEELEX BR
Sealant System Selector Bot
Want to know which sealant you need for your cladding system?
Simply say “Help” to start the chat below, then follow these steps:
Select the type of system you’re installing (e.g. Composite panel).
Choose your panel or system supplier (e.g. Kingspan).
Select the specific panel type (e.g. QuadCore KS1000RW).
Choose the application you need to seal (e.g. Side lap).
You’ll then be shown the recommended sealant, along with a direct link to the product page (e.g. A‑5 x 6 x 9.6 A‑Grade Strip Sealant).
Below the product information, you can restart the process by selecting the type of system.
Please always double‑check your specific project drawings before placing an order.
Some FAQs
Here are some of the frequently asked questions we get asked about strip sealants.
Yes — FS‑3×12×15 is an intumescent strip sealant tested to BS 476 Part 22:1987, commonly used to seal firewall applications, providing 30‑minute smoke & fire resistance.
“Butyl” in roofing is a general term, whereas the Fixfast SafeSeal® is a Class A Butyl strip sealant range, a carefully controlled formulation with PIB (Polyisobutylene) for impermeability, weather/ozone resistance, flexibility, and long service life.
Yes — NFRC TB36 defines Class A (high performance) and Class B (minimum performance) categories for butyl strip sealants; MCRMA documents detail correct placement and compression at laps. We align our recommendations to those frameworks and OEM specifications.
Mistakes to avoid (and how to get it right)
Clean, dry, and degrease surfaces; even slight moisture or residue undermines adhesion.
Apply as a continuous strand, do not stretch, and do not overlap; knead joints and ensure uninterrupted contact.
Butyl must be compressed between surfaces; use correct fixing patterns/positions to deliver pressure at the sealant line.
Ensure that at end or side laps you select the specified bead/section and position relative to primary fixings as per MCRMA/NFRC and OEM details.
Apply above ~5–10 °C where possible; in colder conditions, warm materials and increase pressure. Store rolls cool/dry.
Follow the panel/rooflight manufacturer’s details and use specified sizes (e.g., larger beads for variable joint thickness at rooflights).
- Silicone and cartridge sealants
- Tapes and strip sealants
- Construction foam
