SikaHyflex® GA-WS-305

Weatherproofing sealant




SikaHyflex® GA-WS-305 is a neutralcuring

silicone sealant with a high

movement capability and excellent

adhesion to a wide range of substrates.


Product Benefits


– Meets requirements of ASTM C

920 (class 50), TT-S00230C, TTS001543A

– Outstanding UV and weathering


– Adheres well to many substrates

including glass, metals, coated

and painted metals, plastics and


– Provided with CE-mark according

to EN 15651-1:2012, F EXT-INT

CC 25LM, EN 15651-2:2012, G

CC 25LM, certified by Control

Body 111


Areas of Application


SikaHyflex® GA-WS-305 can be used

for weatherproofing and sealing

applications where durability under

severe conditions is required.

SikaHyflex® GA-WS-305  is particularly

suited as a weather seal for curtain

walling and windows.

This product is suitable for professional

experienced users only.

Tests with actual substrates and

conditions have to be performed to

ensure adhesion and material




Application Limits


Do not use SikaHyflex® GA-WS-305 on

pre-stressed polyacrylate and

polycarbonate elements as it may

cause environmental stress cracking


The compatibility of gaskets,

backer rods and other accessory

materials with SikaHyflex® GA-WS-305

must be tested in advance.

Joints deeper than 15 mm have to

be avoided.

The above information is offered

for general guidance only. Advice

on specific applications will be

given on request.