How do you repaint stucco that has multiple layers of old paint in Ottawa?

Repainting stucco with multiple layers of old paint on it is one of the most common exterior maintenance questions we get in Ottawa, and the good news is that it is absolutely manageable as a homeowner project — provided the underlying stucco is in solid condition and you use the right products for our climate.

Assessing What You Are Working With First

Before you open a single can of paint, the most important step is understanding what is underneath those old layers. Multiple coats of paint on stucco can create a thick, brittle film that traps moisture and eventually leads to peeling, bubbling, and even stucco damage — especially through Ottawa's brutal freeze-thaw cycles. Press firmly on the painted surface in several spots around your home. If you hear a hollow sound or feel the paint flex away from the stucco, you likely have delamination starting, and that needs to be addressed before any repainting happens. Solid, well-adhered paint that simply looks tired or faded is a much easier situation to work with.

Check carefully for cracks in the stucco beneath the paint. Hairline cracks under 3mm wide are common and manageable. Cracks wider than 5mm, or any crack showing vertical or horizontal displacement where one side sits higher than the other, should be assessed by a professional before you paint over them. Painting over structural cracks just hides the problem while the freeze-thaw cycle continues to do damage underneath.

The single biggest mistake Ottawa homeowners make is painting over old stucco without proper surface preparation, then wondering why the new paint peels within a season or two.

Surface Preparation Is Everything

Start with a thorough pressure wash using a wide-angle tip at moderate pressure — around 1,500 to 2,000 PSI is typically appropriate for stucco. You want to remove dirt, mildew, chalking, and any loose paint without blasting into the stucco texture itself. Let the surface dry completely for at least 48 to 72 hours before doing anything else. In Ottawa's humid spring and fall conditions, give it longer if you can.

If you have areas of peeling or bubbling paint, those sections need to come off entirely. A stiff brush, paint scraper, or oscillating tool can help remove loose material. Once you have cleaned back to a solid surface, fill any cracks with a flexible, paintable caulk or elastomeric crack filler rated for exterior masonry use. Do not use standard latex caulk — it will not hold up through Ottawa winters. Feather the filler carefully so it blends with the surrounding texture as much as possible.

If the old paint is in very poor condition across large areas, you may want to consider having a contractor apply a fresh skim coat of acrylic stucco finish before repainting. This is more involved but gives you a clean, uniform base and essentially resets the clock on your exterior.

Choosing the Right Paint for Ottawa Stucco

This is where many homeowners go wrong. Elastomeric paint is the only type you should use on Ottawa stucco. Regular exterior latex paint, even high-quality products, lacks the flexibility to bridge the micro-movement that stucco experiences through 50-plus freeze-thaw cycles each Ottawa winter. Elastomeric paint stretches and recovers rather than cracking, and it forms a waterproof film that keeps moisture out of the stucco system.

Look for a 100% acrylic elastomeric masonry paint rated for below-freezing flexibility. Brands like BASF, Sherwin-Williams Loxon, or Tremco all make products appropriate for Ottawa's climate. Expect to pay $60 to $120 per pail for quality elastomeric paint — this is not the place to cut corners. A typical Ottawa home will require 2 to 4 pails depending on wall area and how porous the old surface is.

Apply a masonry primer or elastomeric primer first, especially if the old paint is heavily chalked or if you have done significant patching. Primer dramatically improves adhesion and helps even out the porosity differences between patched areas and original stucco. Apply two finish coats of elastomeric paint, allowing full drying time between coats as specified by the manufacturer.

Timing Your Project in Ottawa

Stucco painting has the same temperature restrictions as stucco application itself. Paint must be applied when ambient temperatures are consistently above 10 degrees Celsius and are not expected to drop below 5 degrees Celsius for at least 48 hours after application. This means your practical window in Ottawa runs from mid-May through early October. Avoid painting in direct hot sun, which causes the paint to dry too fast and reduces adhesion. Early morning on overcast days is ideal.

Do not paint stucco that is still damp from rain. Wait a minimum of 24 hours after any rainfall, and longer in cool or humid conditions. Ottawa's spring weather can be unpredictable, so check the forecast carefully before you start.

This is a project most homeowners can handle themselves with proper preparation and the right materials. If you find significant cracking, delamination, or moisture damage once you start digging into the surface, that is the point to bring in a professional. You can browse stucco contractors in the Ottawa area through the Ottawa Construction Network directory at justynrookcontracting.com — it is a free resource and a good starting point for getting quotes if the project turns out to be more involved than expected.