I recently removed a large tree that was growing in the corner between the house (raised foundation) and a porch addition. The porch walls are stucco covered cinder block and it appears there isn't much of a footing. It appears to just be sitting on the dirt. I've cut the tree stump pretty far back and now there are just these large remaining roots running under the porch foundation. The soil is very compacted and I don't want to risk any further damage by continuing to dig out the remaining roots. How should I handle this situation? Should I just leave the roots and fill the dirt back in? Do I need to now shore up the area I dug out? If I leave the roots ,won't that weaken the soil under the foundation once they rot? Any pointers would be greatly appreciated.

I need to fill a gap, about 1/2" wide between the garage floor and the approach apron. The stuff I used the last time worked well, held up for a long time, still had a bit of elasticity, and required a chisel to break it away from the edges so the bond was good. But it looks like the apron settled just a slight bit, cracking down the middle, so time to replace. Problem now though is that it lasted a long time, I'm thinking around 15 years or more, and darned if I can remember what I used. So I'm looking at two options, both that I think should be quality products, and wondering if anyone has any preference or whatever for either Quikrete concrete gap filler of Sikaflex gap filler.