Pine Advantages
Pressure-treated pine is substantially less expensive than redwood. While sealing every two years is recommended, pine will not turn an unattractive blackish-gray color like redwood can over time if not sealed. It is 60 percent stronger than redwood in the same application even though both are classified as soft woods. Pine can be used for stairs and structural members unlike redwood. Pressure treated pine structures can resist rot for decades. Pine forests regenerate much quicker than redwood forests, so pine is a more sustainable natural resource.

Redwood Disadvantages
Sustainability is an issue due to limited growth sites and slow regeneration. Redwood trees can take more than 80 years to mature. Redwood structures often need additional steel support brackets. This is because redwood can’t be used alone for structurally significant members or heavy traffic areas like stairs because it is too soft. Also, redwood loses its attractive cinnamon color and turns blackish-gray if a waterproof sealant is not applied on an annual basis. It also becomes susceptible to rot within five years.

Read more: Redwood Vs. Pine | eHow.com http://www.ehow.com/info_12013507_redwood-vs-pine.html#ixzz2E5wWtAFG