What surfaces does it work on?

It is made for smooth surfaces such as metal, masonry, concrete and existing roof coatings. Clean and dry the area first so the mastic bonds.

Can it be used indoors?

Yes. It is rated for interior and exterior use, so it works on basement walls and other interior cracks as well as roofs.

How thick should I apply it?

Apply it thick enough to bridge the crack and feather the edges. Multiple thin coats work better than one heavy coat on wide gaps.

Will it crack in cold weather?

The elastomeric formula is designed to stay flexible through freeze-thaw cycles and severe weather without cracking or peeling.

It is a white finish coat on its own. Painting over it is not required, and the white surface reflects heat.

Is one gallon enough for a roof?

Coverage depends on crack size and surface texture. A gallon handles spot repairs and seams; full roof coating needs several containers.

Lanco Siliconizer Crack Filler 1 Gal. White Elastomeric Roof Patch

Best price now

$19.98at WalmartChecked Nov 12

Prices are checked against each store and labelled with when.

Visit Walmart

Lanco Siliconizer Crack Filler 1 Gal. White Elastomeric Roof Patch

Best price now

$19.98at WalmartChecked Nov 12

Prices are checked against each store and labelled with when.

Visit Walmart

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Price facts

Last seen at $19.98 at Walmart on Nov 12.

Our take on the Lanco Siliconizer Crack Filler 1 Gal. White Elastomeric Roof Patch

Lanco Siliconizer Crack Filler is a one-gallon white elastomeric mastic for sealing leaks and bridging cracks on roofs and other smooth surfaces. It is silicone-modified styrene acrylic, so it stays flexible and is meant to hold up through freeze-thaw cycles and heavy weather without cracking, peeling or crumbling. It suits homeowners patching flat roofs, seams, flashing and masonry who want a thick, brushable coating rather than a thin caulk. Against basic asphalt roof cement, it offers more stretch and a cleaner white finish, but it is a surface patch, not a full roof coating system.

Best forPatching roof leaks and seamsBridging cracks on flat roofs and masonryDIY exterior repairs in cold or wet climatesCoating flashing and vents

Pros

Stays flexible after curing
Bridges wide cracks on smooth surfaces
Adheres to many substrates
White finish reflects sun and blends with light roofs
Suitable for interior and exterior use

Cons

Thick mastic is slow to apply by brush
Needs dry, clean surface for good adhesion
Not a substitute for structural roof repair
White color can show dirt over time

Lanco Siliconizer Crack Filler 1 Gal. White Elastomeric Roof Patch prices at every store

WalmartNew
In stock
$19.98+ $5.99 shippingChecked Nov 12
Visit Walmart

What reviewers say

4.3 / 566 ratings

Buyers rate it well overall and mostly report it sealing leaks and holding through weather. Complaints center on application effort and surface prep.

What people mention

Leak sealingPraisedBuyers say it stops leaks on roofs and seams that other sealers did not fix.
FlexibilityPraisedOwners report it stays elastic and does not crack after weather exposure.
ApplicationMixedSome find the thick mastic slow to brush out, especially in cooler conditions.
Surface prepCriticisedReviewers note it only bonds well on clean, dry surfaces and can fail otherwise.

About the Lanco Siliconizer Crack Filler 1 Gal. White Elastomeric Roof Patch

Lanco Siliconizer Crack Filler is a white mastic for interior and exterior use. It is 100% elastomeric and made from styrene acrylic that is silicone-modified.

It seals leaks and bridges cracks on smooth surfaces, and it fills cracks of any size. The flexible mastic adheres to any surface. It does not crack, peel or crumble, even after exposure to severe weather.

Type: Elastomeric crack filler and roof patch mastic
Composition: 100% elastomeric, styrene acrylic, silicone-modified
Color: White
Size: 1 gallon
Use: Interior and exterior

Specifications

color: WhiteSource
size: GallonSource

Questions and answers

What surfaces does it work on?: It is made for smooth surfaces such as metal, masonry, concrete and existing roof coatings. Clean and dry the area first so the mastic bonds.
Can it be used indoors?: Yes. It is rated for interior and exterior use, so it works on basement walls and other interior cracks as well as roofs.
How thick should I apply it?: Apply it thick enough to bridge the crack and feather the edges. Multiple thin coats work better than one heavy coat on wide gaps.
Will it crack in cold weather?: The elastomeric formula is designed to stay flexible through freeze-thaw cycles and severe weather without cracking or peeling.
Can I paint over it?: It is a white finish coat on its own. Painting over it is not required, and the white surface reflects heat.
Is one gallon enough for a roof?: Coverage depends on crack size and surface texture. A gallon handles spot repairs and seams; full roof coating needs several containers.
Where is the Lanco Siliconizer Crack Filler 1 Gal. White Elastomeric Roof Patch cheapest?: At Walmart, for $19.98, as of our latest check.
What do buyers say about the Lanco Siliconizer Crack Filler 1 Gal. White Elastomeric Roof Patch?: Rated 4.3 out of 5 from 66 ratings.

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