Interior Surface Preparation Guidelines

The best paint we make will not perform as intended if applied over a poor surface. Clean and dry, glossy surfaces dulled, stains, mildew and other contaminants removed all are critical to optimal paint performance.

If there is one absolute guarantee with paint it's that it will fail if not applied to a properly prepared surface.

The information listed here will give you a detailed guide to making sure your paint project works. They are not intended to be all inclusive as each paint project can have unique situations that need to be addressed to insure a good paint job.

If you can't find an answer to your needs here, please email "Ask the Pro" or call 800-383-8406 and we'll make sure you get the answers you need.

Wood - New
      To Be Painted
      To Be Stained and/or Clear Coated
   Previously Finished (Paint or stain/clear finish)
      To Be Painted
      To Be Stained and/or Clear Coated

Plaster - New
      To Be Painted
    Previously Finished
      To Be Painted

Concrete and Masonry - New
      To Be Painted
   Previously Finished
      To Be Painted

CMU (Concrete Masonry Unit, Cinder Block) - New
      To Be Painted
   Previously Finished
      To Be Painted

Gypsum Board (Drywall, Sheetrock) - New
      To Be Painted
   Previously Finished
      To Be Painted

Interior Ferrous Metal, Steel/Iron - New
      To Be Painted
   Previously Finished
      To Be Painted

Interior Non-Ferrous Metal, Aluminum/Galvanized - New
      To Be Painted
   Previously Finished
      To Be Painted

Each system will have a link (Top) to return to the beginning of this page.

Wood - New (Top)
To Be Painted

1. If mildew is present or suspected treat with a 3:1 water and household bleach solution, leaving it on for 20 minutes and adding more as it dries. Wear eye and skin protection. Rinse thoroughly and let dry.
2. Remove any dirt by scrubbing with detergent and water. Rinse thoroughly and let dry.
3. Dull any glossy areas of wood (“mill glaze”) by sanding with medium (120) grit sandpaper. Wear eye protection, dust mask and work gloves.
4. Fill any gouges with wood filler; let dry and sand flush.
5. Fill gaps (1/8” to 1/4”) with quality acrylic or siliconized acrylic caulk, and immediately smooth it flush. Allow to dry over night and make a second application if needed. Do not sand caulk applications.
6. Lightly sand the entire area to be painted with fine (220) grit garnet paper and then dust off with clean tack rags.

Wood - New (Top)
To Be Stained and/or Clear Coated

1. If mildew is present or suspected treat with a 3:1 water and household bleach solution, leaving it on for 20 minutes and adding more as it dries. Wear eye and skin protection. Rinse thoroughly and let dry.
2. Remove any dirt by scrubbing with detergent and water. Rinse thoroughly and let dry.
3. Dull any glossy areas of wood (“mill glaze”) by sanding with medium (120) grit sandpaper. Wear eye protection, dust mask and work gloves.
4. Fill any gouges or splits with wood filler that accepts stain specified. Let dry and sand flush.
5. Lightly sand the entire area to be painted with fine (220) grit sandpaper, and then dust off with clean tack rags.
6. For maximum smoothness, dampen the wood and let dry 30 minutes prior to the final sanding step (repeat step above).

Wood - Previously Finished (Paint or stain/clear finish) (Top)
To Be Painted

(*NOTE: If lead is suspected in the original paint, do not attempt to remove paint or scrape, sand, use heat gun, etc., which might release lead into the environment, rather contact a contractor qualified for lead paint assessment and abatement.)
1. If mildew is present or suspected treat with a 3:1 water and household bleach solution, leaving it on for 20 minutes and adding more as it dries. Wear eye and skin protection. Rinse thoroughly and let dry.
2. Remove any dirt by scrubbing with detergent and water; pay special attention to kitchen areas (accumulated airborne cooking oils) and around switches and door knobs (hand prints and oils). Rinse thoroughly and let dry.
3. Dull any glossy areas with fine (220) grit sandpaper. Wear eye protection, dust mask and work gloves.
4. Fill any gouges with wood filler; let dry and sand flush.
5. Feather sand edges of remaining tightly adhering paint by sanding with fine (220) grit sandpaper. Wear eye protection, dust mask and work gloves.
6. Fill gaps (1/8” to 1/4”) with quality acrylic or siliconized acrylic caulk, and immediately smooth it flush. Allow to dry over night and make a second application if needed. Do not sand caulk applications.
7. Lightly sand the entire area to be painted with fine (220) grit garnet paper and then dust off with clean tack rags.

Wood - Previously Finished (Paint or stain/clear finish) (Top)
To Be Stained and/or Clear Coated

1. If mildew is present or suspected treat with a 3:1 water and household bleach solution, leaving it on for 20 minutes and adding more as it dries. Wear eye and skin protection. Rinse thoroughly and let dry.
2. Remove any dirt by scrubbing with detergent and water. Rinse thoroughly and let dry.
3. Dull any glossy areas with fine (220) grit sandpaper. Wear eye protection, dust mask and work gloves.
4. All existing clear finish must be removed if a new stain color is desired. When the new stain color is lighter than the existing color, a wood stain remover must be used. Follow the wood remover manufacturers recommendations for use.
5. Fill any gouges or splits with wood filler that accepts stain specified. Let dry and sand flush.
6. Lightly sand the entire area to be finished with fine (220) grit sandpaper, and then dust off with clean tack rags.

Plaster - New (Top)
To Be Painted

1. If mildew is present or suspected treat with a 3:1 water and household bleach solution, leaving it on for 20 minutes and adding more as it dries. Wear eye and skin protection. Rinse thoroughly and let dry.
2. New plaster, depending on thickness, temperature and humidity, requires a minimum of 30 days to dry to insure surface alkalinity is acceptable. The PH should be between 6 and 9 prior to paint application.
3. Remove any dirt by scrubbing with detergent and water. Rinse thoroughly and let dry.
4. Dull any glossy areas with medium (120) grit sandpaper. Wear eye protection, dust mask and work gloves.
5. Fill any gouges with patching plaster; let dry and sand flush.
6. Fill gaps (1/8” to 1/4”) with quality acrylic or siliconized acrylic caulk, and immediately smooth it flush. Allow to dry over night and make a second application if needed. Do not sand caulk applications.

Plaster - Previously Finished (Top)
To Be Painted

Concrete and Masonry - New (Top)
To Be Painted

1. If mildew is present or suspected treat with a 3:1 water and household bleach solution, leaving it on for 20 minutes and adding more as it dries. Wear eye and skin protection. Rinse thoroughly and let dry.
2. New concrete and masonry, depending on temperature and humidity, requires a minimum of 30 days to dry to insure surface alkalinity is acceptable. The PH should be between 6 and 9 prior to paint application.
3. Remove any dirt by scrubbing with detergent and water. Rinse thoroughly and let dry.
4. Dull any glossy areas with medium (120) grit sandpaper. Wear eye protection, dust mask and work gloves.
5. Remove any loose or protruding masonry excess by a stiff scraper. (A hammer may be necessary to chip hardened areas.)
6. Fill any gouges with concrete patch; let dry and sand flush.
7. Fill gaps (1/8” to 1/4”) with quality acrylic or siliconized acrylic caulk, and immediately smooth it flush. Allow to dry over night and make a second application if needed. Do not sand caulk applications.
8. Gaps larger than 1/4” should be prefilled with foam backer rod prior to application of a quality acrylic or siliconized acrylic caulk.

Concrete and Masonry - Previously Finished (Top)
To Be Painted

(*NOTE: If lead is suspected in the original paint, do not attempt to remove paint or scrape, sand, use heat gun, etc., which might release lead into the environment, rather contact a contractor qualified for lead paint assessment and abatement.)
1. If mildew is present or suspected treat with a 3:1 water and household bleach solution, leaving it on for 20 minutes and adding more as it dries. Wear eye and skin protection. Rinse thoroughly and let dry.
2. Remove any dirt by scrubbing with detergent and water. Rinse thoroughly and let dry.
3. Dull any glossy areas with medium (120) grit sandpaper. Wear eye protection, dust mask and work gloves.
4. Fill gaps (1/8” to 1/4”) with quality acrylic or siliconized acrylic caulk, and immediately smooth it flush. Allow to dry over night and make a second application if needed. Do not sand caulk applications.
5. Gaps larger than 1/4” should be prefilled with foam backer rod prior to application of a quality acrylic or siliconized acrylic caulk.

CMU (Concrete Masonry Unit, Cinder Block) - New (Top)
To Be Painted

1. If mildew is present or suspected treat with a 3:1 water and household bleach solution, leaving it on for 20 minutes and adding more as it dries. Wear eye and skin protection. Rinse thoroughly and let dry.
2. New concrete and masonry, depending on temperature and humidity, requires a minimum of 30 days to dry to insure surface alkalinity is acceptable. The PH should be between 6 and 9 prior to paint application.
3. Remove any dirt by scrubbing with detergent and water. Rinse thoroughly and let dry.
4. Dull any glossy areas with medium (120) grit sandpaper. Wear eye protection, dust mask and work gloves.
5. Remove any loose or protruding mortar excess by a stiff scraper or wire brush.
6. Fill any gouges with concrete patch; let dry and sand flush.
7. Fill gaps (1/8” to 1/4”) with quality acrylic or siliconized acrylic caulk, and immediately smooth it flush. Allow to dry over night and make a second application if needed. Do not sand caulk applications.
8. Gaps larger than 1/4” should be prefilled with foam backer rod prior to application of a quality acrylic or siliconized acrylic caulk.

CMU (Concrete Masonry Unit, Cinder Block) - Previously Finished (Top)
To Be Painted

(*NOTE: If lead is suspected in the original paint, do not attempt to remove paint or scrape, sand, use heat gun, etc., which might release lead into the environment, rather contact a contractor qualified for lead paint assessment and abatement.)
1. If mildew is present or suspected treat with a 3:1 water and household bleach solution, leaving it on for 20 minutes and adding more as it dries. Wear eye and skin protection. Rinse thoroughly and let dry.
2. Remove any dirt by scrubbing with detergent and water. Rinse thoroughly and let dry.
3. Dull any glossy areas with medium (120) grit sandpaper. Wear eye protection, dust mask and work gloves.
4. Fill gaps (1/8” to 1/4”) with quality acrylic or siliconized acrylic caulk, and immediately smooth it flush. Allow to dry over night and make a second application if needed. Do not sand caulk applications.
5. Gaps larger than 1/4” should be prefilled with foam backer rod prior to application of a quality acrylic or siliconized acrylic caulk.

GYPSUM BOARD (Drywall, Sheetrock) - New (Top)
To Be Painted

1. If mildew is present or suspected the best option is to replace the gypsum board.
2. Remove any dirt by stiff broom or compressed air. Wear eye protection, dust mask and work gloves.
3. Determine the level of finish required to insure the proper application of taping and joint compound provides the desired results.
4. The amount of finish sanding to achieve the smoothness desired will require the use of either drywall sanding screens and/or sand paper.
5. Fill any gouges with joint compound; let dry.
6. Fill gaps (1/8” to 1/4”) with non-shrink spackle and immediately smooth it flush. Allow to dry over night and make a second application if needed.
7. Gaps larger than 1/4” should be cut out and patched with scrap gypsum board followed by the required taping and joint compound.

GYPSUM BOARD (Drywall, Sheetrock) - Previously Painted (Top)
To Be Painted

(*NOTE: If lead is suspected in the original paint, do not attempt to remove paint or scrape, sand, use heat gun, etc., which might release lead into the environment, rather contact a contractor qualified for lead paint assessment and abatement.)
1. If mildew is present or suspected treat with a 3:1 water and household bleach solution, leaving it on for 20 minutes and adding more as it dries. Wear eye and skin protection. Rinse thoroughly and let dry.
2. If it is determined any mildew present has penetrated the previous coatin of paint into the drywall it is recommended to replace the affected areas.
3. Remove any dirt by scrubbing with detergent and water. Rinse thoroughly and let dry.
4. Dull any glossy areas with medium (120) grit sandpaper. Wear eye protection, dust mask and work gloves.
5. Fill gaps (1/8” to 1/4”) with quality acrylic or siliconized acrylic caulk, and immediately smooth it flush. Allow to dry over night and make a second application if needed. Do not sand caulk applications.
6. Gaps larger than 1/4” should be prefilled with foam backer rod prior to application of a quality acrylic or siliconized acrylic caulk.

Interior Ferrous Metal, Steel/Iron - New (Top)
To Be Painted

1. Remove any dirt, grease and other contaminants by scrubbing with detergent and water. Rinse thoroughly and let dry.
2. Remove rust scale and/or rust staining by means of hand tool cleaning and /or power tool cleaning. Wear eye protection, dust mask and work gloves.
3. Grind any weld slag, metals burrs and other metal protrusions to smooth the surface using power tool cleaning.
4. Optionally, a “Rust Converter” solution may be used when flash rust staining is present. Refer the the rust converter manufacturers recommendation for use.

Interior Ferrous Metal, Steel/Iron - Previously Finished (Top)
To Be Painted

(*NOTE: If lead is suspected in the original paint, do not attempt to remove paint or scrape, sand, use heat gun, etc., which might release lead into the environment, rather contact a contractor qualified for lead paint assessment and abatement.)
1. If mildew is present or suspected treat with a 3:1 water and household bleach solution, leaving it on for 20 minutes and adding more as it dries. Wear eye and skin protection. Rinse thoroughly and let dry.
2. Remove any dirt by scrubbing with detergent and water. Rinse thoroughly and let dry.
3. Dull any glossy areas with medium (120) grit sandpaper. Wear eye protection, dust mask and work gloves.
4. Optionally a chemical de-glossing agent may be used. Refer the the deglosser manufacturers recommendation for use. Wear eye protection, dust mask and work gloves.
5. Remove rust scale and/or rust staining by means of hand tool cleaning and /or power tool cleaning. Wear eye protection, dust mask and work gloves.
6. Grind any weld slag, metals burrs and other metal protrusions to smooth the surface using power tool cleaning.

Interior Non-Ferrous Metal, Aluminum/Galvanized - New (Top)
To Be Painted

1. Remove any dirt, grease and other contaminants by scrubbing with detergent and water. Rinse thoroughly and let dry.
2. Optionally, a “Conversion Coating” may be used to prepare the substrate for coating application. Refer the the conversion coating manufacturers recommendation for use.
3. Grind any metals burrs and other metal protrusions to smooth the surface using power tool cleaning.

Interior Non-Ferrous Metal, Aluminum/Galvanized - Previously Finished (Top)
To Be Painted

(*NOTE: If lead is suspected in the original paint, do not attempt to remove paint or scrape, sand, use heat gun, etc., which might release lead into the environment, rather contact a contractor qualified for lead paint assessment and abatement.)
1. If mildew is present or suspected treat with a 3:1 water and household bleach solution, leaving it on for 20 minutes and adding more as it dries. Wear eye and skin protection. Rinse thoroughly and let dry.
2. Remove any dirt, grease and other contaminants by scrubbing with detergent and water. Rinse thoroughly and let dry.
3. Dull any glossy areas with medium (120) grit sandpaper. Wear eye protection, dust mask and work gloves.
4. Optionally a chemical de-glossing agent may be used. Refer the the deglosser manufacturers recommendation for use. Wear eye protection, dust mask and work gloves.
5. Grind any metals burrs and other metal protrusions to smooth the surface using power tool cleaning.

After the drywall is in and the joints are smoothed, the right primer will make your finish look beautiful.

Texture applications add design and depth which demand proper sealing and priming.