How to make paint on your home's exterior last

Protect the exterior of your home by giving it the right paint job.

• Latex paint is more flexible than alkyd paint, but alkyd, also commonly called oil paint, penetrates better into bare wood.
• For this reason, you'll get the longest-lasting job if you prime bare wood with alkyd primer and then use topcoats of latex, according to the experts at Benjamin Moore paint company.
• Alkyd topcoats used outdoors tend to become brittle, and they chalk (that is, shed powder) and don't hold their colour as well as latex.
• Plus, latex paints clean up with water instead of messy mineral spirits.
• Latex paints are also kinder to the environment. Never use alkyd primer or paint to recoat latex. The flexible latex layer will cause the brittle alkyd topcoat to crack.

• Latex paint is water-based — which means that, until it dries, latex paint is soluble in water.
• So to ensure the paint will stick for many years to come, make sure that the surface you are painting is perfectly dry when you apply the paint and will remain that way until the paint dries.
• This means you don't want to start painting in the morning until the dew burns off, and don't paint at all if rain is predicted for that day.

• Hot, dry weather is perfect for painting — the paint will suck right into the dry wood, creating a strong, long-lasting bond.
• If your climate has cool nights and hot days, however, be careful.
• If you paint a cool surface that will become hot in a few hours, the paint may blister within a couple of days.

The right tools and techniques are just as important as the right paint. Here are three simple pointers for a long-lasting job:

• Buy the best paintbrush. Use natural bristle brushes for alkyd paint, and a synthetic bristle one for latex. A good brush will pick up lots of paint and lay it down thick and smooth.

• Thoroughly stir the paint before you use it, drawing the solids up from the bottom until you achieve a smooth consistency.

• To minimize unsightly lap marks, always maintain a wet edge — that is, always work out from the wet edge of a recently painted area.

• If you are applying a finish to bare exterior wood siding and trim, you have the option of using stain instead of paint.
• You can use semi-transparent stain, which colours the wood but leaves the grain visible. Or you can use solid-coloured stain — essentially thinned paint that obscures the grain without completely obscuring the texture of the wood.
• The advantage of stain is that it has an oil or resin base that penetrates into the wood instead of simply adhering to the surface like paint.
• This means stain won't peel off as paint may do if there is a moisture problem. (Solid-coloured stain penetrates less than semi-transparent because pigment stays on the surface, so it can peel, but not as readily as paint.) Unlike paint, you can use stain on weathered wood.
• And because stain is thinner than paint, you can recoat many more times before you have enough buildup to require stripping.
• The disadvantage is that stain is much less durable than paint and must be recoated more often depending on conditions — perhaps every three years for semi-transparent or five years for solid-coloured stain. A good paint job, by comparison, can last up to a decade.