foundationretaining-wall
Is there a minimum distance needed between a retaining wall and a home?
I've seen many homes with a sloped back yard, such that there is a 6' high above ground retaining wall between the backyard and the rear of the home, usually with a distance of 3-5' between home and wall. I often wonder if the home could be built out back to basically incorporate the retaining wall as part of the building structure.
If you have access to a sawz-all also called a Tiger saw or reciprocating saw you can cut the spikes. Pry the timbers one at a time to get a little separation. Using the longest metal cutting saw blades you can get in the 14 tooth per inch range saw thru the spike. The longer blade will allow you to cut the spike if it is on the far side of the timber. Depending on what type of spike was used you may be looking at using several packs of blades. The process may get tougher near the bottom if they anchored the timbers to the ground with rebar.
I built a retaining wall in a situation very similar to what you described. In my case the wall drops approximately 12" over 40 feet. It has 3 courses of 6" Keystone wall blocks. The first course is mostly buried and the wall is about 12" high over most of it's length. I also put about 4" - 5" inches of drain rock behind it with a landscape fabric barrier.
This was 15 years ago and it seems to be holding up just fine. I would hope that the 4" blocks you want to use will be ok. However, I've worked with that size some doing garden walls and they are definitely less stable than the bigger blocks.
One other consideration here is aesthetics. Make sure looking at a retaining wall that isn't level doesn't bug you! Sometimes I look at mine and wish I had installed it level and stepped it down instead.
In the area where I live we have an assortment of gravity block retaining walls and the ones that follow the slope usually don't look as good in my opinion.
Here is a photo for reference:
Best Answer
Are you talking about a retaining wall above the house's ground level, or below?
If above, you will need to provide enough clearance for any emergency exits but other than that I can't think of any limit. As for being built into the house, you could think of a walk-out basement as having a retaining wall on the uphill (non-walkout) side.
If you are talking about a wall below the house, you need to make sure you don't undermine the house's foundation. The distance you need to be away depends partly on the soil so if you are wanting to get close to the house (say, closer than 2 or 3 times the wall height) you would definitely want to talk to an engineer.