Rotten wood and siding material are nearly worthless to paint, as they will do nothing but to continue to deteriorate. You have a couple of options. Replace the siding or wood trim with new components, or in the case of small areas, use a wood hardener and match with an exterior filler product, such as a wood filler. Be sure to prep and sand either one prior to painting.
Climate is another factor to consider. Sunlight, wind, rain and salty weather can all wear out exterior paint. Oil-based paint is durable against wind, rain and temperature changes, but sunlight tends to degrade it. Alkyd paint chalks and sheds very thin layers when it begins to wear. Latex paint is the more durable option for very sun-drenched and relatively dry climate areas. Latex paint with high vinyl content should be avoided, however. Acrylic resin is by far the more durable binder for outdoor latex paint. Arvada Home Painting
Whether you decide to do the preparation work yourself or have a professional do it as part of your project, proper preparation makes all the difference in creating a smooth and lasting finish. Do it correctly the first time or you’ll quickly end up spending more to fix peeling and chipping paint. Follow this process before starting on your home's exterior. Keep in mind that the process may vary based on your siding materials: House Painting Arvada
The other difficult part is getting a painting contractor to show up. While this generalization does not apply to every painter, you can rarely get a paint contractor to show up to look at the house and to later produce a written estimate. It's hardly the fault of the painting contractors; it is a combination of the contractors being smaller operations along with a high demand for their work. House Painting Arvada