SIKA Sikaflex-221 White Polyurethane Sealant and Adhesive, 10.1 fl oz

SIKA Sikaflex-221 is a white, multi-purpose sealant and adhesive in a 10.1-fluid-ounce size. Its listed polyurethane composition and paste form suit buyers seeking one product for sealing or bonding, while application requires clean, dry surfaces and finishing before the surface skins over.

At a glance

The listing describes a one-component urethane paste for sealing and bonding.
Manufacturer claims adhesion to metals, plastics, metal primers and coatings, and ceramic materials.
The cartridge is described as compatible with electric, pneumatic or manual application guns.
The listing says the product cures through exposure to atmospheric moisture.

Price

$11.10Save 16%

Reference price: ~~$13.18~~

Price checked: Nov 12, 2026

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Often bought together

SIKA Sikaflex-221 Multi-Purpose Sealant/Adhesive, White, 10.1 fl. oz | Fills cracks up to 1.5 in, Skin time under 60 minutes,

$8.48

Pros and cons

Pros

One product is presented for both sealing and bonding across several listed material types.
The stated 10.1-fluid-ounce volume gives buyers a defined single-item size.
The listing identifies roof, vent and pipe surfaces as recommended applications.

Technical specifications

11 specifications

Identity
Brand	SIKA
Model	017-90891

Product details
Color	White
Material	Polyurethane
Form	Paste
Liquid volume	10.1 fluid ounces
Number of items	1
Surface recommendation	Roof, Vent, Pipe
Maximum gap fill	1.5 inches

Dimensions and installation
Weight listed	10.1 ounces

Materials and protection
Water resistance listed	Waterproof

What to know before buying

The listing says surfaces should be clean, debris-free, grease-free, oil-free and dry before application. Tooling and finishing should be completed before the skin forms, typically within an hour. The under-60-minute skin-time claim is approximate.

What’s in the box

Included

AP Products Sikaflex-221, white

Who is it for?

A good fit for

Buyers needing a white sealant and adhesive for listed roof, vent or pipe applications.
Projects involving listed metal, plastic, coated-metal or ceramic surfaces, subject to application requirements.

Less suited to

Buyers who need a confirmed cure time or application suitability for a surface not identified in the listing.

SIKA Sikaflex-221 White Polyurethane Sealant and Adhesive, 10.1 fl oz · photo 2 — Additional product photo 2

Customer reviews on Amazon

4.6 / 5 · 3,153 ratings

5 stars80%80%
4 stars11%11%
3 stars4%4%
2 stars1%1%
1 star4%4%

Customer feedback describes the sealant as effective, with RV roofs and vertical walls specifically mentioned. Reports on adhesion and durability are mixed: some customers describe good bonding and lasting seals without cracking or shrinking, while others say dispensing is difficult or mention expiration issues. These experiences matter for roof and wall projects, but they do not establish a specific cause or guarantee performance. The ratings skew positive overall, though a smaller share is unfavorable.

Positive themes

Customers report effectiveness, including on RV roofs and vertical walls.

Mixed feedback

Adhesion feedback ranges from good bonding to difficulty getting the sealant out of the tube.
Durability feedback includes reports of lasting seals as well as concerns about expiration issues.

Frequently asked questions

What material is Sikaflex-221 listed as?

The listing identifies it as a polyurethane paste and describes it as a one-component urethane sealant and adhesive.

What preparation does the listing recommend?

It says surfaces should be clean and dry, without debris, dirt, grease, oil or dust. Complete tooling and finishing before the surface skins over, typically within an hour.

Which surfaces are listed as recommended?

The listed surface recommendation is roof, vent and pipe. The feature text also claims bonding to metals, plastics, metal primers and coatings, and ceramic materials.