So,

I've lived in my brick house for about 3 years now. The home is ~ 25 yrs old and I have always had some questions about the rear part of the slab foundation.

All around the house the slab is even with the ground which I think reinforces the cement, but in the backyard, the slab is raised about 10" off the ground.

There are rail road ties that act as a sort of retaining wall placed about 1.5ft away from the actual slab. There are 3 small cracks in the foundation and those have lead up to the house causing 3 small stair step cracks. I have since fixed those and chalked it up to the house settling after 25 yrs.

I was wondering if it would be smart to dig out the dirt area between the foundation and the rail road tie and fill it with cement, the right way to create more support and use some nice looking cinder blocks as a better retaining wall.

 

The slab is concrete not cement. At least, that's what it should be. If the slab wasn't supported correctly when the house was built, I don't think that replacing the dirt & the railroad ties will add much more.

What is there a second slab & a wall to the right of the railroad ties?

 

Do you mean your house slab continues past the outside wall by 3 feet all the way around the house? I have never seen a slab construction like that before. Are you sure the slab outside was not added later, and is independent of the house?

 

If the slab extends beyond the walls rain would migrate under the wall and you end up with an indoor swamp.

 

Truly I do not know a lot about foundations.

This ~3ft walkway is around the entire perimeter of the house, only causing minor stair step cracks in maybe 3 places. The slab could have been added afterward. It does seem that the floor of the house sits higher than the ground outside though, by maybe 6" or so?

The second slab, is what I consider to be a patio type of thing? The cinder block wall is the wall that surrounds my yard. I never really knew why there was another slab other than a bbq area or a place for chairs.

The space between the rail road ties and extended slab/cement area was full of lava rock and small plants. It has since been removed (mostly) because of the dogs running around outside.

Currently I'd want to remove the railroad ties and use some nice looking cinder blocks as the "retaining wall". I just don't know how it fits into my home's design? I also don't want my foundation to be compromised and have an extremely messed up situation.

I can take more pictures if needed?

 

I dont think you have anything to worry about in regards to your house foundation. The 3ft walkway around the house seems to be more decorative than anything. You can safely rebuild the retaining wall if you wish, or even remove the walkway completely.