Damp internal walls need more than a fresh coat of paint: the right product depends on the wall material and whether moisture is still getting in. Zinsser PERMA-WHITE is made for interior painted surfaces where mildew resistance matters, Drybase is a damp-proof membrane for several substrates, and KILZ is designed for concrete and masonry. First find and address the source of damp; paint alone is not a fix for an active leak or ongoing moisture problem.
Table of Contents
Quick Comparison
| Product | Best suited for | Key feature | Important limitation |
|---|---|---|---|
| Zinsser PERMA-WHITE Mold & Mildew Proof Interior Paint | Interior walls needing a washable finish | Self-priming; paint film resists mold and mildew | Does not address the source of damp |
| Drybase Liquid Damp Proof Membrane | Walls and floors where a damp-proof barrier is needed | Two-coat membrane for several substrates | Listed coverage is about 1 m² per 1 litre |
| KILZ Basement and Masonry Waterproofing Paint | Concrete, brick, and cinder block | Made for masonry and rated to block water pressure up to 12 PSI | Not for active water leaks or floors |
Our Picks: Best Paint For Damp Internal Walls reviews
Best Interior Finish for Mildew-Prone Walls: Zinsser PERMA-WHITE
Zinsser PERMA-WHITE is an interior paint aimed at walls where moisture can make mildew a concern. Its self-priming formula is designed to require no sanding, and the eggshell finish is described as washable and scrubbable with soap and water. That makes it a practical choice for a painted interior surface that needs regular cleaning.
The product contains a mildewcide intended to prevent mold and mildew growth on the paint film. Its five-year guarantee applies to that film, not to the wall structure or the cause of damp. It will not stop water entering through a leak or correct persistent condensation, so deal with those issues before painting.
Compared with the other picks, PERMA-WHITE is the clearest fit for a typical interior wall that already has a suitable painted surface. It is not described as a waterproofing membrane or a masonry barrier, so choose Drybase or KILZ instead when the job calls for those functions and the substrate matches.
Pros:
- Self-priming formula requires no sanding, according to the product description.
- Paint film is designed to resist mold and mildew for five years.
- Washable, scrubbable finish can be cleaned with soap and water.
- Made specifically for interior use.
Cons:
- Does not repair the source of moisture or stop an active leak.
- Its mold and mildew protection applies to the paint film only.
Verdict: Choose PERMA-WHITE for a washable interior finish with mildew resistance when the damp source has been addressed and you do not need a masonry waterproofing coating.
Best Damp-Proof Barrier for Multiple Substrates: Drybase Liquid Membrane
Drybase is a liquid damp-proof membrane rather than a standard decorative wall paint. The product description says it can be used on walls and floors, indoors and outdoors, and on substrates including brick and timber. Its intended role is to form a barrier against moisture ingress and ground gases, so it may suit a repair that needs more than a mildew-resistant topcoat.
The listed application calls for two coats, with an initial drying time of one hour. The stated coverage is about 1 m² per litre, so plan carefully and check the product directions for the surface you are treating. A single litre may cover only a small area, especially when two coats are required.
Drybase is the most barrier-focused option in this group, but it is not automatically the best choice for every damp interior wall. Check that the intended substrate and any planned finish are compatible with the product instructions before applying it. Unlike PERMA-WHITE, it is not presented primarily as a washable decorative interior paint; unlike KILZ, it is not limited in the supplied description to masonry.
Pros:
- Designed as a damp-proof membrane for walls and floors.
- Listed for use on several substrates, including brick and timber.
- Described as suitable for interior and exterior use.
- Two-coat application has a stated one-hour initial drying time.
Cons:
- Approximate coverage is only 1 m² per litre.
- It is important to confirm substrate and finish compatibility before use.
Verdict: Consider Drybase when you need a damp-proof membrane for a compatible wall or floor substrate, and verify the coverage and application instructions before buying.
Best for Basement Concrete and Masonry: KILZ Waterproofing Paint
KILZ Basement and Masonry Waterproofing Paint is made for concrete, brick, cinder block, stucco, and other masonry surfaces. It is intended for interior and exterior use, making it a better match for a damp basement masonry wall than an ordinary wall paint. The product description says its coating can block water pressure up to 12 PSI.
This coating has clear limits: it is not for floors or walls with active water leaks. For below-grade use, the product instructions call for filling holes and cracks with hydraulic cement before painting. The stated drying information is one hour to touch and four hours before recoating, with full curing taking 7–14 days.
KILZ is the strongest fit here when the wall is masonry and water infiltration is the concern. It is not the right pick for a typical drywall surface, and it does not replace repairs to leaks or cracks. For an interior finish focused on mildew resistance, PERMA-WHITE is more directly targeted; for a broader membrane product, compare Drybase’s substrate and coverage instructions.
Pros:
- Designed for concrete, brick, cinder block, stucco, and other masonry surfaces.
- Listed for interior and exterior use.
- Made to block water pressure up to 12 PSI.
- Product description gives clear touch-dry and recoat times.
Cons:
- Not for active water leaks or floors.
- Below-grade holes and cracks need preparation with hydraulic cement.
Verdict: Choose KILZ for suitable concrete or masonry walls where waterproofing protection is needed, but only after addressing leaks and preparing the surface as directed.
How to Choose Paint for Damp Internal Walls
Identify the wall material
Start by checking whether the surface is drywall, brick, concrete, cinder block, or timber. The products here are not interchangeable: KILZ is specified for masonry, Drybase lists several substrates such as brick and timber, and PERMA-WHITE is an interior paint. Read the product label to confirm that your exact surface is suitable.
Find and address the source of moisture
Paint can protect a coating or help form a barrier, but it cannot repair plumbing leaks, water entry, or ongoing condensation. Resolve the cause first, and do not use KILZ on a wall with an active water leak. If you are unsure where the moisture is coming from, consider getting the wall assessed before covering it.
Choose between a decorative paint and a barrier coating
A washable, mildew-resistant finish and a damp-proof membrane serve different purposes. PERMA-WHITE is aimed at an interior finish whose paint film resists mold and mildew. Drybase is described as a membrane, while KILZ is a waterproofing coating for masonry. Match the product to the job rather than choosing by the word “damp” alone.
Check surface preparation and application requirements
Follow the label for cleaning, repairs, coats, and drying times. KILZ calls for hydraulic cement to fill holes and cracks below grade. Drybase is listed as a two-coat product, with approximate coverage of 1 m² per litre. PERMA-WHITE is described as self-priming and requiring no sanding, but still check its full directions for your particular surface.
Plan for the area and the final finish
Estimate the wall area before ordering, paying close attention to the listed coverage and number of coats. Also check whether you need a decorative finish, a white coating, or a membrane suited to later layers. When combining products, confirm compatibility from their instructions rather than assuming one can be applied over another.
Frequently Asked Questions
Can paint stop damp from coming through an interior wall?
Some coatings are designed to resist moisture or form a damp-proof barrier, but paint does not fix the underlying cause of damp. Repair leaks and address water entry or condensation before coating the wall.
Which of these products is best for ordinary interior walls?
Zinsser PERMA-WHITE is the most direct fit for an interior painted surface where a washable finish and resistance to mold and mildew on the paint film are priorities. Check that the existing wall surface is suitable and address the moisture source first.
Can I use KILZ on drywall?
The supplied product information lists concrete, brick, cinder block, stucco, and other masonry surfaces. It does not list drywall, so choose a product specifically suitable for your wall material.
Does PERMA-WHITE remove mold from a wall?
No. Its mildewcide is described as preventing mold and mildew growth on the paint film only. It is not a mold-removal product and does not correct moisture in the wall.
Can KILZ be used where water is actively leaking?
No. The product description specifically says it is not for walls with active water leaks. Fix the leak before considering a coating.
How much Drybase should I plan for?
The listed approximate coverage is 1 m² per litre, and the product calls for two coats. Use the product directions and your measured area to estimate how much you need.
Should I paint over a damp wall right away?
Do not coat a wall until you understand why it is damp and have followed the chosen product’s surface-preparation instructions. Covering an unresolved moisture problem can leave the underlying issue in place.
Final Recommendation
For most interior painted walls where mildew resistance and washability are the main concerns, Zinsser PERMA-WHITE is the most straightforward choice in this group. Choose KILZ for suitable concrete or masonry walls that need a waterproofing coating, and consider Drybase when a membrane is the better match for your substrate and project. In every case, deal with the cause of damp before painting.
