Short answer: DRYLOK Extreme has the stronger published specs for damp basement walls. KILZ Basement & Masonry Waterproofer is a reasonable pick for light dampness. Neither product stops an active leak.
You are standing in a basement that smells like a wet dog's gym bag. You have two cans in the shop aisle and one decision. This KILZ vs DRYLOK guide helps you pick the right waterproofing product without guesswork.
We did not lab-test either paint. This comparison relies on manufacturer labels, data sheets and EPA guidance, all linked below. Both brands are sold mainly in the US, so UK readers should check local availability.
KILZ vs DRYLOK at a Glance
This table lists what each manufacturer states publicly. Where a brand does not publish a number, we say so.
| Feature | KILZ Basement & Masonry Waterproofer | DRYLOK Extreme |
|---|---|---|
| Base | Water-based, low odor | Latex-based |
| Published pressure rating | Not stated on the KILZ product page | Tested to ASTM D7088 at 15 psi |
| Coats required | Minimum of two | Two for the warranty |
| Dry to touch / recoat | 1 hour / 4 hours | See the data sheet for your tin |
| Full cure | 7 to 14 days | At least one week before pool use |
| Coverage per gallon | 75 to 125 sq. ft. | Varies by surface and method |
| Warranty | 10 years, original buyer only, not transferable | 15 years on prepared bare masonry |
| Not for | Floors, active leaks | Foot-traffic floors |
Sources: KILZ product page; DRYLOK specification sheet; DRYLOK product data sheet.
Warranty Length Compared
Warranties show how much a brand trusts its own product. Both come with conditions, so read the fine print.
Manufacturer warranty terms. Neither covers labor, and both require correct surface prep.
What KILZ Basement & Masonry Waterproofer Offers
KILZ designed this paint for porous concrete and masonry. Its product page lists basement walls, retaining walls, cinder block, stucco and brick.
- Low odor, which helps in a closed basement.
- Dries to touch in one hour and takes a recoat after four.
- Covers 75 to 125 sq. ft. per gallon, depending on surface porosity.
- Carries a VOC level of 100 g/L, according to the label.
- Works on dry or slightly damp walls, per the instructions.
The limits matter more than the perks. KILZ states that the product is not for floors or for walls with active water leaks. The warranty also ends if you sell the house.
What DRYLOK Extreme Offers
DRYLOK Extreme targets harder jobs. Its documentation covers above-grade and below-grade masonry, including block, brick, stucco and bare concrete.
- Tested to ASTM D7088 hydrostatic pressure at 15 psi.
- Exceeds ASTM D6904 wind-driven rain resistance at 140 mph.
- Carries a 15-year warranty on a properly prepared bare masonry surface.
- Needs two coats to qualify for that warranty.
- Requires back-brushing the first coat to fill pinholes when you roll it.
Home Depot's listing says the warranty is fully transferable. It also equates 15 psi to a 33-foot wall of water. DRYLOK says its coating may go over sound previous coatings, but the warranty becomes void.
Sources: DRYLOK specification sheet; Home Depot listing; DRYLOK product data sheet.
Hydrostatic Pressure: The Part Most Guides Skip
Hydrostatic pressure is groundwater pushing against your foundation. Saturated soil leans on the wall and forces water through any weak spot. Paint sits on the inside and takes the hit.
Hunker reports that waterproofing paints typically resist 8 to 12 psi. It adds that groundwater is often under higher pressure, so active leaks keep coming. A basement waterproofing contractor makes a similar point: paint does not stop seepage through cracks and can trap condensation.
Here is what that means for your choice:
- Light dampness or efflorescence: either product may help.
- Repeated seepage after rain: fix drainage first.
- Visible cracks or a wet wall-floor joint: repair before painting.
- Standing water: call a qualified professional.
Sources: Hunker; Basement Systems.
Which Waterproofing Product Fits Your Situation?
| Your situation | Better fit | Why |
|---|---|---|
| Below-grade wall with recurring damp patches | DRYLOK Extreme | Published 15 psi test and longer warranty |
| Quick refresh of a mostly dry block wall | KILZ | Low odor and fast recoat time |
| You may sell the house soon | DRYLOK Extreme | Warranty is described as transferable |
| Basement floor | Neither | Both labels exclude floors or foot traffic |
| Water actively running in | Neither | KILZ says no active leaks; fix the source |
Our pick: choose DRYLOK Extreme when pressure is a concern. Choose KILZ when the wall is mostly dry and you want an easier job. Check the price on the day, because we found no verified price data.
How to Apply Either Product
Preparation decides whether your coating lasts. The KILZ label spells out the steps, and DRYLOK follows similar logic.
- Let new concrete cure for at least 30 days.
- Press tape onto the wall, then yank it off. If concrete comes with it, remove the loose material.
- Patch below-grade holes and cracks with fast-setting hydraulic cement.
- Remove dirt, dust, oil, mildew and efflorescence.
- Apply the first coat and work it into every pore and void.
- Apply the second coat and inspect for pinholes.
- Recoat any pinholes you find.
Mind the weather. KILZ recommends air and surface temperatures between 50 and 90°F for best results. DRYLOK Extreme lists an ambient air temperature of 50°F or higher.
Sources: KILZ product page; DRYLOK Extreme data sheet.
Mistakes That Ruin a Waterproofing Job
- Painting over active water. The EPA states that the key to mold control is moisture control.
- Skipping the second coat. Both labels require at least two.
- Thinning the paint. KILZ says do not dilute.
- Coating a floor. Both brands say no.
- Ignoring outdoor water. Clogged gutters and poor grading feed the problem.
Water problems rarely start in one spot. Our guide on roof moss and hidden home damage shows how outdoor moisture spreads. Planning to finish the space afterwards? See these home renovation ideas for more functional living space.
Source: EPA, A Brief Guide to Mold, Moisture and Your Home.
Frequently Asked Questions
Can KILZ or DRYLOK stop an active basement leak?
No. KILZ says its product is not for walls with active leaks. Fix the water source first, then coat the wall.
How many coats do KILZ and DRYLOK need?
Both labels call for a minimum of two coats. DRYLOK also requires two coats to keep its warranty valid.
Can I use these products on a basement floor?
KILZ says not to use its waterproofer on floors. DRYLOK Extreme is not recommended for horizontal surfaces under foot traffic.
Which one has the longer warranty?
DRYLOK Extreme lists 15 years on prepared bare masonry. KILZ lists 10 years for the original residential purchaser.
Final Verdict
DRYLOK Extreme wins on published specs. It lists a 15 psi test and a longer warranty. KILZ wins on convenience for light jobs, thanks to low odor and a four-hour recoat.
Still, paint is a finishing step, not a drainage system. Diagnose the water source, repair cracks, then pick your can. Your basement will thank you, quietly, without the damp smell.
Sources
- KILZ Basement & Masonry Waterproofer (kilz.com)
- DRYLOK Extreme specification sheet
- DRYLOK Extreme product data sheet (drylok.com)
- DRYLOK Extreme data sheet (Sika USA)
- Home Depot product listing
- Hunker: Basement Waterproofing Paints, Do They Work?
- Basement Systems: Concrete Foundation Waterproofing
- US EPA: A Brief Guide to Mold, Moisture and Your Home
Short answer: DRYLOK Extreme has the stronger published specs for damp basement walls. KILZ Basement & Masonry Waterproofer is a reasonable pick for light dampness. Neither product stops an active leak.
You are standing in a basement that smells like a wet dog's gym bag. You have two cans in the shop aisle and one decision. This KILZ vs DRYLOK guide helps you pick the right waterproofing product without guesswork.
We did not lab-test either paint. This comparison relies on manufacturer labels, data sheets and EPA guidance, all linked below. Both brands are sold mainly in the US, so UK readers should check local availability.
KILZ vs DRYLOK at a Glance
This table lists what each manufacturer states publicly. Where a brand does not publish a number, we say so.
| Feature | KILZ Basement & Masonry Waterproofer | DRYLOK Extreme |
|---|---|---|
| Base | Water-based, low odor | Latex-based |
| Published pressure rating | Not stated on the KILZ product page | Tested to ASTM D7088 at 15 psi |
| Coats required | Minimum of two | Two for the warranty |
| Dry to touch / recoat | 1 hour / 4 hours | See the data sheet for your tin |
| Full cure | 7 to 14 days | At least one week before pool use |
| Coverage per gallon | 75 to 125 sq. ft. | Varies by surface and method |
| Warranty | 10 years, original buyer only, not transferable | 15 years on prepared bare masonry |
| Not for | Floors, active leaks | Foot-traffic floors |
Sources: KILZ product page; DRYLOK specification sheet; DRYLOK product data sheet.
Warranty Length Compared
Warranties show how much a brand trusts its own product. Both come with conditions, so read the fine print.
Manufacturer warranty terms. Neither covers labor, and both require correct surface prep.
What KILZ Basement & Masonry Waterproofer Offers
KILZ designed this paint for porous concrete and masonry. Its product page lists basement walls, retaining walls, cinder block, stucco and brick.
- Low odor, which helps in a closed basement.
- Dries to touch in one hour and takes a recoat after four.
- Covers 75 to 125 sq. ft. per gallon, depending on surface porosity.
- Carries a VOC level of 100 g/L, according to the label.
- Works on dry or slightly damp walls, per the instructions.
The limits matter more than the perks. KILZ states that the product is not for floors or for walls with active water leaks. The warranty also ends if you sell the house.
What DRYLOK Extreme Offers
DRYLOK Extreme targets harder jobs. Its documentation covers above-grade and below-grade masonry, including block, brick, stucco and bare concrete.
- Tested to ASTM D7088 hydrostatic pressure at 15 psi.
- Exceeds ASTM D6904 wind-driven rain resistance at 140 mph.
- Carries a 15-year warranty on a properly prepared bare masonry surface.
- Needs two coats to qualify for that warranty.
- Requires back-brushing the first coat to fill pinholes when you roll it.
Home Depot's listing says the warranty is fully transferable. It also equates 15 psi to a 33-foot wall of water. DRYLOK says its coating may go over sound previous coatings, but the warranty becomes void.
Sources: DRYLOK specification sheet; Home Depot listing; DRYLOK product data sheet.
Hydrostatic Pressure: The Part Most Guides Skip
Hydrostatic pressure is groundwater pushing against your foundation. Saturated soil leans on the wall and forces water through any weak spot. Paint sits on the inside and takes the hit.
Hunker reports that waterproofing paints typically resist 8 to 12 psi. It adds that groundwater is often under higher pressure, so active leaks keep coming. A basement waterproofing contractor makes a similar point: paint does not stop seepage through cracks and can trap condensation.
Here is what that means for your choice:
- Light dampness or efflorescence: either product may help.
- Repeated seepage after rain: fix drainage first.
- Visible cracks or a wet wall-floor joint: repair before painting.
- Standing water: call a qualified professional.
Sources: Hunker; Basement Systems.
Which Waterproofing Product Fits Your Situation?
| Your situation | Better fit | Why |
|---|---|---|
| Below-grade wall with recurring damp patches | DRYLOK Extreme | Published 15 psi test and longer warranty |
| Quick refresh of a mostly dry block wall | KILZ | Low odor and fast recoat time |
| You may sell the house soon | DRYLOK Extreme | Warranty is described as transferable |
| Basement floor | Neither | Both labels exclude floors or foot traffic |
| Water actively running in | Neither | KILZ says no active leaks; fix the source |
Our pick: choose DRYLOK Extreme when pressure is a concern. Choose KILZ when the wall is mostly dry and you want an easier job. Check the price on the day, because we found no verified price data.
How to Apply Either Product
Preparation decides whether your coating lasts. The KILZ label spells out the steps, and DRYLOK follows similar logic.
- Let new concrete cure for at least 30 days.
- Press tape onto the wall, then yank it off. If concrete comes with it, remove the loose material.
- Patch below-grade holes and cracks with fast-setting hydraulic cement.
- Remove dirt, dust, oil, mildew and efflorescence.
- Apply the first coat and work it into every pore and void.
- Apply the second coat and inspect for pinholes.
- Recoat any pinholes you find.
Mind the weather. KILZ recommends air and surface temperatures between 50 and 90°F for best results. DRYLOK Extreme lists an ambient air temperature of 50°F or higher.
Sources: KILZ product page; DRYLOK Extreme data sheet.
Mistakes That Ruin a Waterproofing Job
- Painting over active water. The EPA states that the key to mold control is moisture control.
- Skipping the second coat. Both labels require at least two.
- Thinning the paint. KILZ says do not dilute.
- Coating a floor. Both brands say no.
- Ignoring outdoor water. Clogged gutters and poor grading feed the problem.
Water problems rarely start in one spot. Our guide on roof moss and hidden home damage shows how outdoor moisture spreads. Planning to finish the space afterwards? See these home renovation ideas for more functional living space.
Source: EPA, A Brief Guide to Mold, Moisture and Your Home.
Frequently Asked Questions
Can KILZ or DRYLOK stop an active basement leak?
No. KILZ says its product is not for walls with active leaks. Fix the water source first, then coat the wall.
How many coats do KILZ and DRYLOK need?
Both labels call for a minimum of two coats. DRYLOK also requires two coats to keep its warranty valid.
Can I use these products on a basement floor?
KILZ says not to use its waterproofer on floors. DRYLOK Extreme is not recommended for horizontal surfaces under foot traffic.
Which one has the longer warranty?
DRYLOK Extreme lists 15 years on prepared bare masonry. KILZ lists 10 years for the original residential purchaser.
Final Verdict
DRYLOK Extreme wins on published specs. It lists a 15 psi test and a longer warranty. KILZ wins on convenience for light jobs, thanks to low odor and a four-hour recoat.
Still, paint is a finishing step, not a drainage system. Diagnose the water source, repair cracks, then pick your can. Your basement will thank you, quietly, without the damp smell.
Sources
- KILZ Basement & Masonry Waterproofer (kilz.com)
- DRYLOK Extreme specification sheet
- DRYLOK Extreme product data sheet (drylok.com)
- DRYLOK Extreme data sheet (Sika USA)
- Home Depot product listing
- Hunker: Basement Waterproofing Paints, Do They Work?
- Basement Systems: Concrete Foundation Waterproofing
- US EPA: A Brief Guide to Mold, Moisture and Your Home
