Do You Need A Primer For Exterior Paint – Some Exciting Facts

priming the wall

Would you like to hear from someone who has spent his fair share of Sunday afternoons painting the exterior of his house? In other words, for exterior painting, I can guide you on which items are worthwhile to purchase and which aren’t. To make a conclusive decision stay tuned!

In most cases, yes, you need a primer for your exterior surfaces. Exterior surfaces are mostly made out of concrete or wood, which are uneven and porous. Primer is crucial for a flawless and long-lasting exterior finish. It makes the surface smooth and fills the holes for an easier coat of paint.  

While the above statement may have addressed your concern, it does not provide a comprehensive view. Exterior house painting is an expensive and time-consuming job. You must know which primers to use and which to avoid so that you can focus on other facets of house improvement.

What Is a Primer?

To have a concise answer to “do I need to prime before painting?” We must first know what it is. A primer is a resin material that provides adhesion on the paint surface and makes it smoother for the paint coat itself. It is an undercoat that serves as the “middle man” between the surface and the final coat of the paint.

A primer also reduces the number of coats you need to apply on a surface by reducing the project’s overall price. So when it comes to primer vs. paint, which one provides a better middle layer? A primer is mostly an on-go choice.

Many different types of primers are commercially being used to paint the exteriors of buildings, but all of them fall under these three basic types:

  • Oil-based primer
  • Latex-based primers
  • Pigmented primers

When Do You Need a Primer?

Many individuals erroneously use primers when they don’t need to, and the opposite is also true. Here is a list of some of the most common situations where you should always use a primer.

  • Whenever you are covering unfinished wood
  • While changing the color of your exterior
  • While painting high glossy surfaces
  • When painting brick walls, chimneys, or other types of masonry surfaces
  • To cover your overt wall stains
  • If you have water bleeding through your walls
  • When your current plaster begins to flake

Categories of Primers Best Suits to Your Exterior

All primers are not built and do not serve the same purpose. To save time and effort, you must consciously choose the primer best suits your painting surface. So if you are wondering, do you need a special primer for exterior paint? We have got you covered.

Have a look at a compiled list of the most common primers that may go well for your home exterior.

1. Wood Primer

You need a primer for wooden surfaces. Your walls, doors, and furniture items require a primer before they are painted. My friends and family, who know me well, always ask about priming their exterior doors, wood walls, and outdoor furniture, and I highly recommend using a good old-fashioned oil-based wood primer for all wooden surfaces. 

Bare wood has the roughest and most porous surface, which causes it to absorb the paint like a sponge. Without a primer, it would take you several coats to paint the whole thing, and even that would not be enough to cover the uneven surface completely. A single layer can fill out the holes and smooth the surface.

A minor downside is oil based primers usually take very long (around 24 hours) to dry, so if you are in a hurry, you can move to a quick-drying latex-based primer which will serve your purpose and consume less time.

2. Drywall Primer

Drywalls may have a smoother texture than bare wood, but their porous surfaces are just as tough as painting wood. It will absorb paint more in some places than others, leading to an even coat that will cause flashing.

Flashing happens when there are visible differences in the final sheen of your paint. A latex primer will fill up pores on the surface and make it smooth. Moreover, the primer is much cheaper per gallon as compared to multiple coats of paint, but if you are wondering, do you have to paint over the exterior primer? Well, in the case of drywall, absolutely; otherwise, you will have a bland exterior.

3. Masonry Primer

When we move towards the relatively warmer regions, we will see most exteriors will have masonry built. A masonry surface generally refers to surfaces made of solid materials like concrete, cement, or sandstone.

In most cases, masonry surfaces have high pH, which reduces their adhesion and makes it difficult for the paint to stick on top. Manufacturers developed a specialized masonry problem that works like a charm on any masonry surface to cope with this issue.

Sometimes white crystalline deposits can develop on a masonry surface called efflorescence. If you are facing this issue, make sure to look for a masonry primer that is efflorescence resistant as well so your walls can have a long-lasting coat.

4. Bonding Primer

Glossy surfaces pose a major difficulty to even the best of primers. They are quite slick, which makes it hard for paint to stick on them without running off. These surfaces might include metal surfaces, ceramic tiles, and plastic or vinyl shutters.

Using an oil-based primer on metal doors or surfaces might get you good results, but in the case of ceramic tiles or plastic/vinyl surfaces, an oil-based primer would be a waste of money. So if you want to paint any of these exteriors, we recommend using a bonding primer to provide extra adhesion to your paint.

5. Stain Blocking Primer

A stain on your exterior wall is not only irritating to the eye, but in some scenarios, it can completely ruin your exterior design, so a primer is needed while painting your exterior.

Water and smoke stains bleeding through your wall are also quite a headache. They are especially bothersome for people living in coastal areas. The producers addressed this consumer pain point through stain-blocking primers.

To combat stains like ink, markers, or grease on your exterior, these stain-blocking primers, in conjunction with a few coats of paint, will make your exterior as good as new.

6. Tinted Primers

Made up your mind to change the color of your exterior? A primer is an essential ingredient to add on. It will not only reduce your paint coats but will also secure them, providing a long-lasting effect.

If you are painting a lighter color over a dark one, tint your primer in that specific color to reduce your time and effort.

You can tint your primer by one of two ways, either ask the retailer to tint it for you or do it yourself in order to save few extra bucks. Just simply mix some of your paint in the primer and you will be good to go.

A Few Tips to Apply Primers

The list mentioned above is by no means exhaustive, and there could be other types of primers specifically made to serve your purpose. Search and pick as per your requirement.

Here we will provide you with some tips to avoid rookie mistakes and choose the right product.

Read and Follow the Instructions Carefully 

Always use the recommended amount and give it ample time to dry up; otherwise, you will not have the same results.

Quick-Drying Primers are Also a Good Option 

Find the specific primer that works best for your project and meets your criteria. If you are short on time and cannot wait for the primer to dry for a day, you can always move to quick-drying primers.

Do not use Interior Primers for Exterior Walls

Exterior primers have much higher VOC levels than interior primers, which makes them resistant to harsh climates and UV rays. In comparison, interior primers have a lower level of VOCs, which gives off much fewer fumes, making them relatively safer for the household. 

You can also read our article and find out if you need a primer for your interior walls here. 

When can you avoid using a primer?

Now let’s move on to the situations where a primer might not be necessary.

1.   Reapplying The Same Color

As mentioned before, a new color-tinted primer is a must ingredient if you are re-painting. But if you are redoing the same shade just to give it a fresh look, a primer is unnecessary. But keep in mind you can only skip the primer if the previous layer is not peeling off.

2.   2-in-1 Combo

Applying the primer and then painting subsequently is a two-step process that can be quite long because you have to wait for the former to dry out.

To address this issue, many manufacturers have developed primers infused paints. These paints have negated the use of primers altogether as they are infused with them. But not all products are equal, so make sure you get your 2-in-1 combo from a trusted brand.

3.   Matte Surfaces

Finally, we move to matte surfaces. Most matte exteriors are already coated with a protective layer which increases their lifetime. These protective layers are provided with matte/vinyl or paint protection films (PPF). These films play the role of a built-in primer, so if you are painting on a surface that is not glossy and relatively smooth, you can totally skip the priming process.

Frequently Asked Questions

What happens if you don’t use a primer before painting the exterior?

 Skipping the priming process while painting your exterior will develop flashing effects, leading to uneven paint patches. Your paint coat will have a shorter lifespan, and you will also run the risk of peeling, especially in humid conditions.

Can regular paint be used as a primer?

Using regular paint as a primer is no different than using multiple paint coats to cover a surface. It is extremely time-consuming, and the results are not as promising as using a primer. Multiple coats will also lead to a higher per-gallon price.

Do you need to prime already painted exterior wood?

The exterior, either finished or already painted, does not need a primer coat. The previous paint has already filled the pores and made the surface even, so using a primer is unnecessary.

What is the best time to paint the house exterior?

The drying process requires moderate temperatures. The best time to paint your house exterior is either spring or fall. You should never paint your exterior in snowfall or rainy seasons. 

You can read about when to paint the interior of your house over here.

Summing Up

Finally-do you need a primer to paint your exterior? The answer is yes in most cases, priming reduces your cost, gives a better finish, and makes your coating resistant to climate and UV rays for an extended time. But now that you are well informed about all the categories of exterior primers and how they are used, you can make an informed decision for your specific exterior and rest easy for a long time.

If you want to know if you need a primer for your interior walls, then click it and let us know what you think!

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