Why You Don't Need Primer
Primer isn't necessary for most paints, as porch paint is already a durable blend. However, it doesn't hurt - a properly prepped and primed surface does give the paint a better surface to stick on. If your surface isn't already primed, you can save the money and skip this step with the right paint. But, if the primer is already applied, there's no need to remove it.
It's also worth noting that while many exterior paints don't require a primer, some still do. Be sure to follow the directions by the manufacturer for the best results. If you do use primer, be sure that it's for the correct surface. For example, a concrete porch needs a concrete primer like this one:
What Paint Do You Use On A Porch?
Porch paint is available in two major types. Oil-based enamel is a shiny finish appropriate for wood surfaces. Latex enamel can be matte or gloss and used on wood or concrete.
This low-luster paint would work for either wood or concrete surfaces.
You can also find paints with anti-skid properties. This concrete paint is slip-resistant. If children or the elderly use the porch frequently, this can prevent a lot of injuries.
Special surfaces, such as PVC., will require specific paints blended just for them.
How Do You Prepare A Porch For Painting?
Remove Paint and Sand
If the porch has paint already peeling or chipping, the first step is to remove the old paint. Be careful if lead paint is involved. If the paint job is from 1960 or earlier, it is likely to be lead. Allowing a professional who is experienced in lead removal may be the safest option.
If it's a DIY job, you can use several methods to remove old paint. Wire brushing or power sanding is particularly effective. You can get a special attachment for an angle grinder to remove paint quickly like this:
Once the paint is removed, be sure to sand the entire surface lightly. This will give a surface for the paint to adhere to.
Need special help getting paint off concrete? See this article: How to remove paint from a concrete porch [7 Methods to Try]
Clean The Surface
After removing the old paint, clean the area well. Vacuum and remove any dust left behind. Then, wash the porch with a mixture of trisodium phosphate and water. This will lift out any surface dirt, making the surface ready to take paint. Rinse well and let dry.
Unpainted Concrete Should Be Etched
If the concrete's surface has never been painted before, it will need to be etched with muriatic acid first. This is typically a job for a professional, as muriatic acid can be hazardous. You should only be attempt this if you are experienced and able to work safely with chemicals.
The necessary mixture is 5-10% muriatic acid and water. Be sure to use proper safety gear, such as goggles, boots, and gloves. Use a one-gallon mixture for every 100 square feet. Be sure to apply the mixture evenly, avoiding puddles.
Scrub with a stiff bristle brush, allowing it to set on the concrete until it stops bubbling. Then, rinse thoroughly with clean water. The solution should dry reasonably evenly in a few hours - if it doesn't, rinse again. You don't want puddles to develop, as the acid will be more concentrated in those spots.
How Long Does Floor Paint Take To Cure?
Curing and drying are two different things, which are important to keep in mind. Oil-based paints may feel dry to the touch after about 6-8 hours. Latex can take as little as one. At this time, you can do a second coat if needed.
However, the paint is not cured yet. Don't move any patio furniture over it or other large items. Avoid walking on it, and limit all use. Using the floor before the paint cures to maximum hardness will cause it to fail early. Give it at least 72 hours to rest. And before cleaning, the paint should have had at least a month to settle. You can read more here: How long does porch paint take to dry?
Most porch and patio paints are specially formulated to be very durable. Because of the high levels of binders in the formula, they often don't require additional primers. However, some do recommend using a primer before painting. Always be sure to read the manufacturer's instructions for your specific product and follow them for the best results.
If a primer is already in place, there's no need to remove it. You can save some money by skipping primer if it's not required. But, primer is simply a new, prepared surface for the paint to adhere to, and it never hurts to have it.
In any case, be sure that any old or peeling paint is removed. The surface should also be lightly sanded or etched in the case of concrete. Clean and rinse thoroughly, and allow to dry before painting. Finally, once painted, leave plenty of time for the paint to cure before use. It should be left untouched for 72 hours and wait at least a month after painting to clean the surface again. By following these steps, you'll have a gorgeous painted porch that will last for a long time!