Is waterproof sealant mastic profitable to sell on Amazon United States?

The niche generates $140K/yr across 14 tracked products. 4 of 8 products launched in the last 360 days are still selling. 90-day search growth is -48.4%. Flapen's verdict: Skip it (44/100).

How competitive is the waterproof sealant mastic niche?

11 brands and 19 sellers compete. The top 5 products take 71% of clicks and top 5 brands hold 79% of demand.

What do buyers complain about in waterproof sealant mastic?

Top complaints mined from reviews: Functionality-Overall, Adhesion/Stickiness, Water Resistance. The return rate is 0.7%.

When does demand for waterproof sealant mastic peak?

Demand peaks in Feb–Jul–Aug; the busiest month runs 2.5× the quietest.

What does it cost to enter the waterproof sealant mastic niche?

Listings span $5.00–$17.55; the average listing price is $10.15 (sweet spot $15–$100). The average incumbent carries 297 reviews — the moat a new listing must climb.

waterproof sealant mastic

Skip it

Soft demand (-48.4% this quarter) — this niche doesn't clear our bar today.

Returns

Incredible0.7%

return rate — above 5% kills the launch gate

Review moat

Great296.86

avg incumbent reviews — the moat a new listing must climb

Conversion

Great9.2%

search→purchase rate — share of searches ending in a sale

Quality gap

Good4.4★

avg incumbent rating — lower means beatable quality

Brand share

Okay79%

top-5 brand share — brands hold most of the demand

Avg price

Okay$10.15

avg listing price — sweet spot $15–$100

Market size

Okay$140K

$140K/yr · 150K searches

Competition

Bad71%

top-5 click share — a locked-up shelf

Price range

Bad$5.00–$17.55

cheapest to priciest tracked listing — scored on the share inside $15–$100

Growth

Bad-48.4%

90-day search growth — must beat 0% to launch

Signals Low Review Barrier

According to Flapen's Amazon United States niche tracking, waterproof sealant mastic is a $140K/yr Amazon United States market (150K searches/yr). The top 5 brands hold 79% of demand. Demand peaks in Feb–Jul–Aug. Verdict: Skip it — 44/100.

Data updated Jul 27, 2026 · scored weekly · How we score niches

waterproof sealant mastic market data

Units sold / yr: 13K–15K; avg 500–750/product
Revenue / yr: $127K–$152K; units × avg price
Conversion rate: 9.2%
Avg BSR: #263
Page quality: 0%
Prime: 100%
Sponsored: 100%
Out of stock: 6.3%
Avg brand age: 44 months
Avg seller age: 166 days

Competition & brand share

The top 5 products capture 71% of clicks — a locked-up shelf that new listings rarely crack.

Brands

11 falling

Sellers

Top-5 brand share

79%

Top 20: 100%

Top-5 click share

71%

Top 20: 100%

Open market

14%

JSWKKGD36%
ZFYOUNG15%
ZXFUTURE10%
SOPAMI9%
KEPTFIT8%
Generic8%
Open — no brand owns it (5 brands, 14%)

Demand & seasonality

Weekly Amazon search volume, last 99 weeks — -48.4% search growth over the last 90 days.

Peak months: Feb, Jul, Aug · busiest ÷ quietest = 2.5×

Open Trend

Top waterproof sealant mastic search terms

sealant clay79K/yr -45.8%7.9% conv.
sealant clay waterproof17K/yr -49.1%6.7% conv.
sealing clay7K/yr +61.5%7.6% conv.
waterproof sealant mastic19K/yr -57.6%7.5% conv.
sealing mastic8K/yr -50.2%13.9% conv.
waterproof sealant clay6K/yr -81.2%5.7% conv.
sealant mastic4K/yr -57.3%12.3% conv.
moldable sealant clay3K/yr -42.6%9.8% conv.
moldable sealant clay waterproof2K/yr -46.9%8.2% conv.
sealing mastic waterproof3K/yr -68.0%12.5% conv.

All search terms

Top waterproof sealant mastic products on Amazon

Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.

Beatable (≤4.3★) Contested Strong incumbent (>4.7★)

All 14 tracked products in this niche — three views at once, no toggling.

Top sellers

by 90-day click share

6 Pack Moldable Sealant Clay White Fast Drying Sealant Mastic Repair Sealing Putty for Drain Pipe Connections Wall Holes Air Conditioning Holes and Household Gap Filling.

JSWKKGD$8.054.1★150 rev

ZFYOUNG 10-Pack Premium Waterproof Wall Repair Sealing Clay Duct Seal Ideal for Wall Hole Repair Air Conditioning and Drainage Pipes Quick and Easy Solution

ZFYOUNG$10.834.5★328 rev

Zxfuture Pack of 8 White Seal Putty Waterproof Duct Seal Repair Sealing Clay Quick Mending Mud for Drain Connection Wall Hole Air Conditioning Hole

ZXFUTURE$11.784.3★675 rev

SOPAMI sealant Clay White Waterproof Sealant Putty-Wall Hole Repair 10pcs

SOPAMI$12.474.1★102 rev

6-Pack New Type White Waterproof Sealant Mastic Repair Sealing Clay Quick Mending Mud for Drain Connection Wall Hole Air Conditioning Hole Waterproof Seal Putty

KEPTFIT$9.804.3★402 rev

Newest

by launch date

XGPGBXGT 10 Pack Waterproof Sealant Clay Moldable Plumbers Putty for Drain Connections Wall Holes & AC Openings Quick Repair Mastic Seal Putty

XGPGBXGT$9.993 rev

2mo ago

6-Pack 2026 Upgraded Sealant Mastic Fast Drying Repair Sealant Clay Quick Mending Putty for Drain Pipe Connection Wall Holes & Air Conditioning Holes

JSWKKGD$7.3422 rev

4mo ago

6 pcs Sealant Mastic Waterproof Wall Repair Sealing Clay for Air Conditioning Hole and Drainage Pipes Gap Wall Hole Repair Quick Mending Mud Putty

Generic$8.885 rev

5mo ago

30 Pcs White Seal Putty Waterproof Sealant Mastic Repair Sealing Clay Quick Mending Mud for Sealing Drain Connections Wall Holes and Air Conditioning Openings Reliable and Efficient

Haodlay$17.555 rev

8mo ago

SOPAMI sealant Clay White Waterproof Sealant Putty-Wall Hole Repair 10pcs

SOPAMI$12.47102 rev

9mo ago

What buyers say about waterproof sealant mastic

What buyers praise and complain about, mined from review topics.

What buyers love

Ease Of Use28%

“Easy to use”

Efficiency11%

“Appear to be working”

Advertised Vs Actual Product11%

“Worked as advertised”

Quality-Overall8%

“it seems to have worked well”

Value For Money7%

“Good value for money”

Water Resistance3%

“Waterproof sealant”

Adhesion/Stickiness3%

“It sticks well”

Durability3%

“it did a great job - I think it will last a long time”

Leak-Proof3%

“there was no leaks”

Size-Overall3%

“Fit perfect”

What buyers complain about

Functionality-Overall23%

“Not effective at all”

Adhesion/Stickiness15%

“Doesn't stick well”

Water Resistance8%

“Not sure if its water resistant either”

Leak-Proof7%

“it was very leaky”

Size-Overall5%

“Each bag is pretty small”

Value For Money5%

“But its not very cost effective due to the price per pack”

Quality-Overall4%

“Product was deficient on the 2nd order”

Durability3%

“not sure about longevity”

Advertised Vs Actual Product3%

“Useless for what they said it was for”

Smell3%

“It doesn't smell much. if at all”

Top return reasons

Functionality-Overall21%

Adhesion/Stickiness17%

Advertised Vs Actual Product15%

Size-Overall10%

Value For Money7%

Leak-Proof6%

Material Quality5%

Water Resistance4%

Defective Material/Parts3%

Quality-Overall2%

Common questions

Is waterproof sealant mastic profitable to sell on Amazon United States?: The niche generates $140K/yr across 14 tracked products. 4 of 8 products launched in the last 360 days are still selling. 90-day search growth is -48.4%. Flapen's verdict: Skip it (44/100).
How competitive is the waterproof sealant mastic niche?: 11 brands and 19 sellers compete. The top 5 products take 71% of clicks and top 5 brands hold 79% of demand.
What do buyers complain about in waterproof sealant mastic?: Top complaints mined from reviews: Functionality-Overall, Adhesion/Stickiness, Water Resistance. The return rate is 0.7%.
When does demand for waterproof sealant mastic peak?: Demand peaks in Feb–Jul–Aug; the busiest month runs 2.5× the quietest.
What does it cost to enter the waterproof sealant mastic niche?: Listings span $5.00–$17.55; the average listing price is $10.15 (sweet spot $15–$100). The average incumbent carries 297 reviews — the moat a new listing must climb.