Hi everyone, this will be my first post to this forum, and I apologize in advance for any mistakes. Before i continue i understand this is a HUGE HUGE HUGE project for me but id like to try, and am prepared to spend the next few months working on it if needed, if i happen to fail or quit, i am prepared to take the loss and hire professionals, but this is just way more fun and satisfying! I've done a ton of research, but have a few remaining questions, And would greatly appreciate your help, review of my process, and any advice. Id like to give you a short explanation of what im dealing with: I live on a VERY steep slope on one side, and the dirt has been eroding for quite some time now, We moved in 2 years ago, and i can only assume that its been eroding for over 10 years. (my best guess is that the slope ranges anywhere from about 50-70 degrees, and is about 15 feet high/tall from the street, and 50 feet wide and about 15 feet deep, from the sidewalk to house) Since it is a home project, I am planning to build two (or more) 4 foot high retaining walls, with at least 1-1/2 block beneath the ground, with the base consisting of 3-5 inches of gravel, followed by 2-3 inches of paver base/sand. (i would also have a perforated drain hose under the the gravel. Do you think this would suffice? Or am i going about this wrong? I understand that even with two walls, id only be up to about 8 feet high, while the slope is around 15 feet tall. What type of wall blocks would you recommend? Solid, hollow, other, or would it not matter? Next question is regarding the landscape fabric, i noticed there are so many, and im not sure if it matters. Many of them advertise weed prevention and im guessing that doesn't matter since its only used to hold back the gravel and dirt. finally, would i need to use adhesive or mortar to glue each block, or would the weight be enough to keep the walls in place? Any and All advice/input is appreciated! Thank You!

We are building a 3 1/2 foot retaining wall and a paver patio, and found that at one portion of the area we are building there are decomposing roots deep underground that cause the ground to be bouncy. Digging some of it up, it digs up easy and just falls apart, it is obvious this tree was cut down probably 10 years ago or more. I'm sure this means the ground will sink even more once they fully decompose. Am I right that our only course of action is to dig out as much of it as possible and fill back in with our native sandy soil before building our patio?