If you are repainting your shed, you may be able to skip the primer, providing the original paint is in fairly good shape. If it is peeling, flaking or deteriorated in large spots, you’ll probably want to remove the paint and start over.
In that case, you’ll want that protective primer. Even if your old paint is in good shape, there are other reasons to use primer, such as painting over stain or using latex paint when the old paint was oil-based. Primer will help the new paint adhere to the old paint.
If you are painting new or raw wood, you really need to have a primer. Primer adds protection and helps the paint cover more effectively. Natural wood absorbs a lot of paint. Primer helps offset this by providing a more solid surface for the paint. It also helps the paint adhere properly to the surface. Besides this, some primers now come with added protections such as those against mold and mildew or against stains. You’re really missing out if you don’t take advantage of the properties of primer.
What Will Happen if You Skip Priming Before Painting?
If you don’t prime your bare wood first, the paint will absorb into the wood, making you apply more coats than you planned just to get some good color. Even with these added coats, the paint may look a little uneven due to different parts of the wood absorbing more paint than others. Primer helps the paint stick better to the surface. If you skip the primer, your paint is much more likely to start chipping off far sooner than it should.
If you’re repainting the shed, and the old coat isn’t in very good shape, primer will help your new paint stick better and more uniformly. It especially helps if the new paint is a different type than the old paint. In addition, primer is better at hiding wood filler that may be needed to fill in cracks or separations in the wood.
What Kind of Paint Do You Use on a Shed?
Exterior acrylic latex paint is generally recommended for use on a shed. This is not a good place to try to save money unless you like having to paint a building every few years. Pick good quality, long-lasting paint for your shed. Along with delaying the repainting project, it will protect your shed from moisture and rot. Ask your supplier for recommendations on paints with a long lifespan.
Another consideration is choosing the best time for painting. A paint job done during times of low humidity and low temperature fluctuations is best. Early summer and early fall are generally considered to be the best seasons for an exterior painting project. Staining may be an option in certain cases, read my article Is it Better to Paint or Stain a Shed? for more details.
How Do You Prepare a Shed for Painting?
New shed – If you just finished your shed, you can probably skip the cleaning step. Do check your shed close up to see if there is any wood dust clinging to the surface. If there is, you’ll need to use a pressure washer or a hose with a pressure nozzle to clean the surface and let it dry for 24 hours.
Tape off any areas that are not meant to be painted, such as door hardware, windows, etc. If you plan to use a lighter paint for trim that has a high contrast to the main color, such as a barn red shed with white trim, you might want to tape off the trim areas as well. If your trim will be a darker color or the same color as the rest of the shed, taping it off is not needed. The primer comes next and can be applied either with a paint sprayer or rollers and brushes.
Repainting shed – Go over the surface to be repainted. Scrape off any peeling paint and splinters and sand the surface smooth. Replace any loose or broken boards. Check for any cracks or minor splits and apply wood filler to the areas. Allow the wood filler to dry completely. Clean the surface thoroughly.
You can use a hose-end sprayer with a detergent and water solution and rinse afterward or use a pressure washer. Let the surface dry for 24 hours. Then you can go to the taping step.
How Do You Paint a Shed with Peeling Paint?
Any peeling paint should be removed, and the area sanded smooth. You can use a paint scraper or metal brush to remove it. Remove any bulging paint also, or any paint that looks as if it is starting to separate from the wood underneath. If there are large patches of peeling paint, it may be best to just remove all the paint and start over.
If you’re dealing with several layers of old paint, you may be able to use a film of wood filler to just fill in the hole left by the removed loose paint. The filler can also protect the surrounding paint edges, so they are less likely to start peeling.
Can You Paint a Shed with a Roller?
Rollers certainly can be used to paint a shed. In fact, many people prefer rollers to paint sprayers, as they find it easier to prevent drips with a roller than with the sprayer. This is especially true of people with little or no experience with a sprayer. Rollers and brushes also don’t require all the problems of preventing the spray from going all over the place.
With a sprayer, you’ll have to cover any bushes, shrubs or desirable plants located any place the paint might drift. You’ll have a much smaller problem with rollers, as all you have to cover are places that might be subject to drips.
Smaller brushes should be used to make sure the paint gets into corners and other tight places. There are short rollers available that may be better to paint your siding, depending on how it is constructed, or to use on trim. Narrow trim can be handled with brushes.
Can You Paint Over a Stained Woodshed?
You can paint over stain on a shed, providing you do some prepping beforehand. If you know whether the stain was latex-based or oil-based, you’ll be better prepared to handle the prep work. Make sure the surface is clean, washing it if necessary, and letting it dry thoroughly.
Since stain usually is applied until it has a glossy surface, it will be hard for paint or primer to stick unless you sand the surface to roughen it first, especially if you are using latex paint over oil-based stain. Use sandpaper with 150 grit or finer and sand with the grain. You may need a de-glosser product afterward, along with gloves and respirator while applying it, as it has strong fumes.
To combat the problems of adhesion and stain color leaking through your paint, look for primer that has stain-blocking properties. Another choice is to have your primer tinted to match the stain. To address the problem of using latex paint over oil-based stain, some suggest using an oil-based or shellac primer.
How Do You Paint Over Old Paint?
Inspect your shed for any peeling or separating paint or paint blisters. You might use a pressure washer if you have more than a little peeling paint to get most of it off so you don’t have so much work later. You will still need to inspect your shed carefully for peeling paint the pressure washer didn’t remove.
Scrape the peeling paint off and sand the area with 150 or 180 grit sandpaper, following the grain. Be sure you don’t miss any peeling paint or paint that looks as though it is starting to separate from the wood. This can be a time-consuming job, depending on the state of the paint, but a very important one to ensure the adhering of your new paint. If there is a lot of peeling, you may need to remove the paint and start over.
If there is no peeling paint, some sources state that the existing paint should still be sanded with 280 grit sandpaper to roughen the surface, allowing your new primer and paint to adhere better. Others state that if the paint is the same type you will use and is in good condition, you can go right to the primer step.
Wash down the exterior with a detergent solution and water, then rinse. This is needed to remove the dust from the sanding. If you find cracks, fill them with wood filler, then sand down the area with 180. An orbital sander may be used here to get the area even. Wipe off the dust left behind with a damp cloth.
After covering windows and other items, it’s time to apply your primer. Unless you are experienced with a paint sprayer and don’t have much in the way for the paint to damage, some authorities recommend using rollers and brushes. It’s also easier to make sure paint gets into all the needed corners and crevices without over-spraying these to ensure coverage and ending up with drips and runs.
Conclusion
When painting a new shed or repainting an existing shed, primer is useful for many reasons, such as paint adherence, protection from stain bleeding through and wood protection. Since most people put off repainting as long as possible, the extra protection from primer can help keep your shed in good condition until you get around to repainting it.