Proper surface preparation is necessary for house painting in Concord. Professional house painters are aware of the benefits of correct and thorough prep work, as it helps paint adhere to the surface better and create a longer-lasting paint job.
What is a substrate?
A substrate refers to the material on which paints, primers, stains, and other coatings are applied. But there is not only one type of substrate! The best paint pros deal with a wide array of substrates. They approach every kind of substrate through a combination of correct preparation, application, and cleanup to produce a solid and long-lasting result.
Common types of substrates found in a home
Drywall
Drywall is a common building material used to construct interior walls only in dry areas (it is not permitted to be installed in bathroom walls). It consists of a paper or water-resistant covering over a core made of gypsum. Install drywall following the manufacturer’s instructions and local building codes.
Preparation – If there are nail pops, set them with a hammer or, in the case of screws, with a screwdriver. Apply a spackle over them to fill the hole, allow the spackle to dry, then sand it smooth.
In case of water damage or insufficient anchors or any fasteners have caused bulges, the damaged area needs to be replaced after the root cause has been corrected.
If there is mold (or mildew), a mold-removing fog bomber might kill the mold and prevent it from returning.
You need to tape and coat joints with several layers of joint compound, leave the compound dry, then sand it smooth.
All the repair work will leave the surface coated with dust and debris, so you have to clean the surface and leave it dry, smooth, and free from dirt before applying primer and paint.
Painting – Use a high-quality acrylic latex primer. For drywall that’s been previously painted, use a stain-blocking primer to conceal any flaws or marks. Finish with top-quality acrylic latex paint.
Wood
Wood is also one of the common substrates for building walls in homes. Wood or plywood should be thoroughly dried with less than 10% moisture content when installed.
Preparation – In case of surface flaws like holes, cracks, or gouges, use a plastic wood filler or putty according to the manufacturer’s instructions. Sand door and window frames, wood trim, and floors until smooth. If the surface was painted with a semi-gloss or gloss before, remove the gloss by sanding. Make sure to clean off the sanding residue with a tack rag.
Painting – Apply the entire surface with a stain-blocking primer. After priming, check the surface to ensure the wood knots aren’t showing through. Otherwise, you need to spot-prime those knots.
Finish with top-quality latex or oil-based paint. You will need to sand between coats with 320-grit sandpaper.
Brick
Brick is a type of masonry. Although brick is usually used for exterior walls, it is also ideal for interior wall construction. New brick must be set for 30 days before you apply any coating. Brick, like all masonry, is porous and thus prone to moisture and mold. It also tends to produce efflorescence – a white powder with limestone or chalk properties and is carried out to the surface by water.
Preparation – Clean the brick using a wire brush to remove dirt, soot, and grime, but be careful not to gouge out any mortar. Next, scrub the masonry with soap and water. After washing, rinse thoroughly and allow it to dry for at least 48 hours.
A heads-up: don’t use a pressure washer in cleaning your brick walls since it can gouge out mortar.
Painting – Apply a coat of top-quality latex primer. Allow the primer to dry. Next, apply top-quality latex paint or any paint formulated explicitly for masonry. Ideally, use a long-nap paint roller to cover the most surface and then a paintbrush to touch up grouts and crevices.
Since brick has a lot of texture, there’s a possibility of dripping paint. Keep an eye out for runs. Apply a second coat.
Since painting brick is a one-off decision, you must be sure about the color and finish of your chosen paint. It’s almost impossible to remove paint from brick.
Plaster or veneer plaster
Plaster also called veneer plaster or skim coat, is a type of cement substrate. It is subject to alkalinity and efflorescence.
Like any masonry, plaster or veneer plaster substrates need to cure for 30 days before being applied with any coating. Its moisture content should be at most 15%. Plaster has high calcium levels, and because it is subject to alkaline contact, an acrylic latex primer is best for plaster substrates.
Preparation – Brush off or vacuum any efflorescence and loose surface material. Fill nibs, cracks, or nail grooves by applying a patching compound.
VERY important – DO NOT SAND plaster or veneer plaster before priming it.
Painting – Apply an acrylic latex primer. Aside from offering better surface adhesion for the topcoat, the acrylic latex primer protects the surface from alkyd products (that can react to free alkali and make the surface less adhesive to paint). Finish with high-quality latex, vinyl acrylic, or alkyd paint.
Concrete
Concrete is also a type of masonry made from a mixture of cement and aggregates.
All concrete substrates should be clean, dry, and free of dust, dirt, oil, grease, wax, soap, or foreign material that may prevent adhesion or affect overall performance.
Preparation – Wash the concrete walls with TSP or any non-residue cleaner. Remove any old, peeling paint for previously painted concrete walls and treat oily areas with a degreaser. Repair cracks, holes, or any flaws with concrete patches according to the manufacturer’s directions. Use a trowel to apply and smooth the patch until it is flush with the wall.
It’s essential to check the concrete walls for any signs of moisture – if your concrete walls are still wicking moisture, the topcoat won’t stick to it. You can check by taping a plastic sheet on the wall. Try to get the sheeting as air-tight as possible. Allow the plastic sheeting to set for 24 hours, then check it. You must seal the wall if moisture is present on the plastic sheeting. If no moisture is present, it means the wall is sealed.
If you have to seal the wall, roll on one coat of concrete sealer and allow it to dry overnight.
Painting – Apply one coat of concrete primer and let it dry for 24 hours. Apply another coat if necessary.
Finish it with concrete paint. You may choose which application method you desire – using a paintbrush, roller, or sprayer. Apply the paint in at least three thin layers. Make sure the paint has no streaks, brush strokes, or lap marks. Allow the paint to dry for 24 hours.
The substrates above are the most commonly used in houses and many businesses. It helps to know the type of substrate in your home to help you determine the correct preparation and what type of paint is needed. Then, when you are ready to begin house painting in Concord, you will know what to do.
