T1-11 is variety of wooden panel siding made of plywood. Each piece of T1-11 siding is routed, so that once installed, it looks like vertical strips of wood. This siding is a very common exterior shed or outbuilding material, but in some parts of the US it is also used on the exterior of homes.

There are many positives about using T1-11, but like all wood products, it requires maintenance. T1-11 siding should be inspected annually (quarterly is even better) so that holes, water or moisture intrusion can be identified and corrected immediately. Hands down, the best way to guard this siding against the elements (and various bugs and critters) and protect and lengthen its lifespan is to paint it.

How to Paint T1-11 Siding

• Clean. Use a pressure washer to remove dirt, mold, and old loose paint. Use a wire brush and paint scraper to remove loose old coating (if applicable.) Be sure to scrub in the grooves of the siding. Allow to dry for at least 24 hours.
• Replace damaged panels. If you discover any loose panels, secure them. If you find a panel damaged beyond repair, replace it. Trust me; it’s worth the minimal investment.
• Caulk. Inspect the caulking around windows and doors. Repair dry-rotted or otherwise damaged caulk by re-caulking.
• Prime. Prime the siding with a heavy acrylic primer. I’ve used XIM Peel Bond with great success. Because of its finish, painting T1-11 siding is rather tricky. Use a roller for large areas, and a brush to get into grooves, and tight spots. Let dry.
• Paint. Apply two coats of exterior acrylic paint. Let the first coat dry completely before you roll the second coat. Apply in the same manner as the primer.
• Re-touch. Once the second coat has dried completely, inspect the siding for any cracks or small holes you may have overlooked. Also, check to be sure you’ve covered all areas with paint.

Tools and materials for painting T1-11 siding.

• Ladder (if applicable)
• Wire brush
• Brush or broom to clean up scrapings
• Paint scraper
• Paint trays or 5 gallon bucket with roller grid

I want to make you aware of a few alternatives before you start painting.

• Spray Vs. Rolling. You can spray rather than roll the exterior primer and paint on the T1-11 siding. If you chose to spray the paint, follow up by back rolling the paint. As soon as you’ve sprayed the paint, use a paint roller or brush (back brushing) to work the paint into the siding. Spraying frequently fails to fill small cracks and grooves on its own- back rolling (and back brushing) help fill these spaces, and creates a smoother finish.
• Elastomeric Vs. Exterior paint. You can use elastomeric paint rather than exterior acrylic paint on T1-11. You’ll find that elastomeric paint costs a bit more (and covers less area per gallon) but it will add a waterproof coating to the siding. Moreover, elastomeric paint is resistant to the elements (even intense direct sunlight and driven rain.) I still advise applying two coats, and using the back rolling method if spraying.

Painting T1-11 is a relatively easy job. Sure, it requires a bit of labor, and a small investment into materials, but overall, it demands nominal skill. Another positive: a small structure (such as a shed) can be completed in just one weekend. Not only will painting extend its life, it will also look much better. If you plan to paint a shed or out building, consider matching the paint color of the structure to that of your home. Painting T1-11 can really make a statement when painted correctly.