we have about 4 years old house that has cambara hardwood siding and deck. both siding and deck were treated with penofin for hardwood. while our siding still looks great our deck does not. during 4 years we had to re-stain deck every spring and every year it looks worse. i am looking for ideas how to correctly prepare and treat my deck this spring. we are in denver colorado and for last two summers it got beated by sun. then in winter snow just finishes the job and by next spring it looks like it was never treated.