Skip to main content

Tips for Staining and Painting T1-11 Siding

  • Author:
  • Updated date:

Matt is a professional painter who owns and operates his own painting business, specializing in interior and exterior house painting.


How often should you paint T1-11 siding?

T1-11 plywood siding was used a lot on homes built in the 1960s through the 1980s before vinyl and composite became the more popular choice. T1-11 plywood siding, not to be confused with the less expensive OSB (oriented strand board) version, which is more susceptible to water damage and rot, is very durable when it's installed correctly and maintained with high quality paint or stain. When the siding is neglected, moisture enters the surface.

Many homes still have the original plywood siding in-tact, and if your home is one of them, the siding should be re-painted every five to seven years to keep it protected from the elements. If the siding is rotting and compromised beyond repair, replacing it is the best option.

Although plywood siding is cheaper and less durable than vinyl, aluminum and composite, I have stained older T1-11 in surprisingly good condition for its age. While T1-11 is a less desirable siding choice by today's standards, the smooth profile of the boards look really nice when professionally painted, or stained. It's actually easier to paint too than more porous siding like cedar.

My favorite siding cleaner.

My favorite siding cleaner.

Prepping T1-11 Siding for Paint, or Stain

The surface of your T1-11 siding should always be cleaned before you paint because dirt build-up and mildew can cause adhesion problems.

The best way to clean your siding is with a gas powered pressure washer because these usually operate at a higher rate of pressure than electric models to make cleaning easier. I own and use the Simpson MegaShot power washer any time I need to clean siding, porches, fences and garage doors for a paint job.

Removing Mildew from T1-11

If you see clusters of dark stains on your siding, it's mildew. Mildew flourishes in high humidity and shade, and it loves to form in the grooves of plywood siding. It's important to chemically treat mildew stains and power wash them before you paint.

The best mildew remover I've used for cleaning siding is Jomax House Cleaner and Mildew Killer. I cycle the cleaner through my power washer and spray it onto the mildew stains with a cleaning tip, allowing the cleaner to eat into the stains for about twenty minutes before I power wash again. A long handle scrub brush works great too for removing dirt and mildew while power washing.

Patch Holes and Damage

Holes in T1-11 are usually caused by woodpeckers searching for bugs to eat. The holes should always be filled before painting or staining. My favorite filler for repairing holes in siding is Bondo Wood Filler with the cream hardener. The filler dries really hard and resists moisture. For deeper holes, pre-fill with expanding foam and then fill with the Bondo I recommended.

Another exterior filler I've had success with is Durham's Water Putty, but Bondo Wood Filler is stronger and dries fast. If needed, caulk around the windows with a flexible and paintable caulk.

Remove Peeling Paint with a Sander

If the paint or stain on your siding is peeling, power washing will remove a lot of it, but not all of it. Sanding and scraping is necessary to remove the rest. The fastest and easiest way to remove peeling paint with less scraping is using a high powered electric remover like the Wagner Paint Eater. This tool is awesome. The Paint Eater is similar to an orbital sander, but it uses an extremely coarse disc that eats through loose paint fast. If you're dealing with badly peeling T1-11, I highly recommend this tool to make the removal process easier.

T1-11 siding I stained with Woodscapes from Sherwin Williams.

T1-11 siding I stained with Woodscapes from Sherwin Williams.

Paint or Stain Your T1-11 Siding with a Sprayer

You can paint or stain plywood siding, but I prefer acrylic stain because it peels less than paint due to the fact that it seeps into the surface instead of forming a heavy layer on top like paint. On rough sawn T1-11, stain will penetrate even better. l also recommend acrylic stain if you want to preserve the wood look of the siding. Paint is a lot thicker and hides more of the surface texture and grain than stain does.

What's the best exterior stain?

The stain I recommend is the acrylic Woodscapes from Sherwin Williams. I've used this product on T1-11 and cedar siding with excellent long-term results. I use the solid stain version, but you can also stain your siding with semi-solid, or semi-transparent. Solid stain offers more UV protection and holds up longer. No primer is needed with this product. I recommend avoiding oil-based stain because it contains chemicals that are a food source for mold and mildew.

What's the best exterior paint?

I'm a big fan of the acrylic Duration paint from Sherwin Williams. This paint is pricey, but you get what you pay for. I've also used Super Paint a lot in the past, but Duration is thicker, yet rubbery when dry, to resist cracking and peeling better than cheaper paints. If you decide to use paint instead of stain, I highly recommend spending a little more and go with a premium paint instead of a cheap one. It's also important to stay on top of a painting maintenance schedule to make prep and repainting easier.

Use an Airless Sprayer, Paint Brush and a Roller

Don't attempt to stain or paint your T1-11 without a sprayer. Manually dipping the brush into the paint can over and over to fill each groove in the siding will take forever. Use an airless sprayer to spray the material onto the surface and into the vertical grooves of the plywood. Working in sections, brush and roll the material into the surface as you spray it on.

Use caution when spraying outdoors. My article How to Control Overspray When Spray Painting Outdoors provides several tips on using a paint sprayer outside and avoiding property damage.

The best airless spray tip size for siding is a 515, or a 517. Both tips produce a 10-inch spray fan, which is perfect for covering large expanses of siding fast. You can spray exterior paint or stain through either of those spray tip sizes, but the larger orifice of the 517 is good for thicker paint. The spray tips and tip guards I've always used with my sprayers are from Graco. For siding, a Graco RAC-5 517 spray tip works great.

If you're spraying the Woodscapes stain I recommended, apply two coats for the best finish and easier touch-up. Even with paint, two coats is best, but if your repainting your siding the same color then one coat is usually fine, unless the surface is in bad condition.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2021 Matt G.