Painting Masonite Siding Correctly

Painting Masonite™ Siding Correctly


Correctly Painting Masonite™  Siding

Painting Masonite™ siding correctly, several steps are involved to ensure lasting beauty and exterior paint protection. Dependent on your paints adhesion characteristics and local weather conditions. The following steps listed will insure proper care when painting Masonite™ siding.

Upon where in the country you live, also what the normal humidity ratings may be, applying exterior paint under the lowest humidity ratings is always recommended. Every city in our country has a normal humidity rating, and if not sure where you live, check with your local weather forecaster.

Some areas of our country may never see humidity ratings lower than 70%, such as in Houston or the Southern coast line. Relative humidity is probably the first factor people should take into consideration when painting exterior siding, as well as others listed below.

Masonite™ siding is a man-made product using wood fibers grown in the United States and abroad,  going through an extensive milling and manufacturing process. Very high quality, and dense in nature, this exterior siding product comes to home improvement stores ready to be painted, coming pre-primed, having a grayish tinted primer painted on exposed surfaces.

Exterior House Painting Tips While Painting Siding



These same exterior house painting suggestions are exact ones we follow, helping procure Masonite™ siding for many additional years to come.

  • Cleaning Masonite™ siding with pressure washer
  • Caulking Masonite™ siding using1050 quick dry siliconized acrylic latex caulk
  • Priming Masonite™ siding any place allowing water to penetrate, soaking into
  • Painting Masonite™ siding two coats, wet on dry spray method 13-16 mils

Cleaning Masonite™ siding

Cleaning Masonite™ siding is done normally by using a high pressure power washer having anywhere from 1500-3500 psi. Careful not to get too close with spray nozzle, as this can damage the siding.

A good rule of thumb is staying away at least 6 feet with spray tip. Most of the time no ladders are needed, for higher points of the home, a "Red" solid stream tip can be used, rinsing from the top down, dirt and debris. Using a mild Eco friendly soap or detergent scrubbing on to surfaces, rinsing off using high pressure washers is recommended.

Cleaning Masonite™ siding allows proper paint adhesion once dried, and cleaning siding is like having a clean painter's canvas to start a new oil painting. Art paintings and a home's exterior siding are existentially the same, only on a much larger scale, and having a clean canvas or siding allows to work with a clean slate, giving way for the final painting having much more appeal, quality and integrity.

Caulking Masonite™ siding

Caulking Masonite™ siding should be done 24-48 hours after any cleaning has taken place. Water from power washing can get in ends of boards next to trim or at bottom edges of siding, not wishing to trap moisture, as this will diminish the life of the caulk. Once caulking opens up, the siding is subject to potential harm and deterioration, so caulking on a dry surface is at the up-most importance.

Best to caulk ends of siding where they meet trim boards. Using a high quality white latex painter's caulk. We generally use Sherwin-Williams 1050, a 55 year caulk.

As the picture below shows, nail heads appear to have "Sunken in" possibly by the pneumatic nail guns having too high of air pressure. This is certainly not the case. What is going on is the exterior paint coating has lost it's protection, allowing moisture to seep into nail shafts, causing Masonite™ siding to expand.

Sunken nail heads is one of the first tale-tailed signs it's time to repaint your exterior Masonite™ siding. If left unattended, these nail heads will continue to sink in because the siding is expanding like a sponge in water.

To properly fix these nail polyps or indention s, caulking is the last thing you will want to use filling them. Although the quickest, as a caulking gun dispenses caulk rather quickly, a can of exterior Spackle should be used. Crawford's Exterior Spackle dries to a flat finish, and when painted, will never flash once paint ages, as caulk continues to be shinny.

I've personally been an advocate and spokesperson having painting over 30 years, I've painted 1000's and seen countless other homes having a poky-dotted look as exterior paint has aged, and caulk was used several years before filling in nail heads.

Another good rule of thumb is caulk only at 90 degree angles, and not where to pieces of siding meet one another. As siding joints are staggered, no water can penetrate the wall surfaces underneath.

Instead of caulking these joints, a metal sleeve can be installed during construction, never seeing these joints and edges again, allowing the ends to breath. Proper caulking of Masonite™ siding is the up-most importance, and your professional painting contractors know best.

Painting Masonite Siding

Priming Masonite™ siding

Priming Masonite™ siding usually never needs this paint product, as it comes from the lumber mills sealed and primed. I have seen some extreme cases where the siding left unattended for many years, will need a primer coat before the final exterior paint coating.

If Masonite™ siding has been neglected and nail heads appear sinking as mentioned above, the bottom edges of this siding normally appears that of a sponge, and should be sealed and primed before painting. This will also help the appearance of it from a aesthetic point of view, not to mention proper paint protection.

Be sure to prime any areas showing deterioration. Any place allowing water to penetrate, as this will eventually swell out, having to replace fairly soon.

This is why you may have seen a house getting painted, during the preparation process, looking like a scalded striped Zebra, priming Masonite™ siding is what is going on and needed.

Remember to prime any oil spots showing through aged paint, coming out of siding. Your exterior paint will properly bond to primer much better.

Painting Masonite™ siding


Painting Masonite™ siding is the last most important thing protecting this high quality exterior sheathing lasting many years, normally the life of the home, if properly cared for.

Applying the proper paint thickness paint coatings is key for the life of the paint itself. New construction normally has no requirements to the thickness of the paint, only applying enough to get by and home sold and occupied.

Most paint manufactures recommend exterior paint coatings consisting of at least 9 mills dry, which wet paint coats would need 13-16 mills. This type of siding can be either brushed rolled or sprayed, knowing spraying with a cross hatch spray method, two coats wet on dry is the best for consistency and uniformity.

Spraying is also more effective way keeping painting cost estimates down, not requiring near as long painting. Rolling and brushing methods take a considerable amount of time longer accomplishing, thereby costing more, as time is money, and money is time. Working from top down, side to side, if needing to stop for some reason, best to complete the entire section or side.

Exterior Painting


Exterior painting can be a daunting task, and hope this helps you painting Masonite™ siding the correct way, making all the difference in the world for your siding's protection and lasting beauty.

Proper painting techniques will insure your Masonite™ siding will stand the test of time, protecting the contents within the home, mainly You~ as Masonite™ siding is a very high quality exterior sheathing.

Hiring a professional house painting contractor in your area can save you time and money, many assist with Free in Home Paint Color Consultation. Saving  time and money with professional house painters also adds value and sense of personal exterior paint decorating, while getting the job done right the first time.

Hiring an exterior painting contractor also provides the least amount of inconvenience while weatherizing and painting your home's siding and trim, which is always a plus.

In Denver Colorado, Eco Paint, Inc., provides some of the best Denver painters, Colorado has to offer, along with these above attributes mentioned.

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How To Paint On Masonite | Properly
7 years ago

Painting Masonite Siding Correctly Eco Paint, Inc. – Painting Masonite™ siding, several steps are involved to ensure lasting beauty and exterior paint protection dependent from your paints adhesion characteristics and techniques fulfilled. Making sure cleaned properly is first order of business, allowing to dry before any paint coatings are applied. Thank you for the article, very informative!

6 years ago

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Julie M
Julie M
1 year ago

Hello Cal Phillips, I am seeking to keep my home in good condition. Built in the 70’s with Masonite board you have given me exactly the information I need to do this job “correctly”. Every question I had was answered. Using spray spackle instead of caulk is genius. I had no idea caulk would eventually show through. It is hot with an average humidity of less than 30% where I live so I can power wash and then spackle in a few days. My house has wooden soffit with peeling paint. I had a contractor check for water damage, there… Read more »