Rehabbing a house on a slab with tree roots, cause for concern?

Question

I recently looked at a house to flip and ended up passing on it and wanted to see if maybe I should have considered it.  The house was built in the 70's and had 2 big trees near the home.  In almost every room there were cracks at the door ranging from just a few inches long to a couple of feet.  In two rooms there was a large crack the length of the vertical wall where the walls meet.  My thought was that the tree was moving the foundation causing the cracks.  I have heard mixed opinions on the tree roots.  If the trees were cut, would the root die?  If not, how do you solve that problem...jack up the house to dig out roots?  I would love to hear what other people think about this.

Matt Devincenzo · Answer

It's hard to say without having seen the damage and knowing more about the area, soil and normal issues for buildings in the area.

I'd suspect that the cracking was due to settling and not the trees. While trees will push concrete up they are usually not as able to damage an entire slab because of the footings and the thickness of a home slab. That's not to say they couldn't have been the cause, just that the only way to have a good idea would be to have it inspected. Trees usually are more damaging to plumbing and exterior slabs and patios that the home itself.

Also all concrete cracks, so some cracks aren't really damage they're just cracks. Usually the width and offset if the crack is more important than the length. If the crack is wide or offset(one side higher than the other) that is where you know there is a problem with the slab either settling or being forced up.

Either way without having more knowledge of the costs to fix you were wise to pass up on it for now.

Stephanie Anson · Answer

Thanks Edward!  Any other comments?

Edward Burns · Answer

Cutting down a tree will kill the roots, but that does not get rid of them.  The roots will take years to decay and if as you suspect they are the cause of the foundation buckling then you may face other problems as the roots decay leaving a void in their place.   You could consider cutting the tree down and  boring out the bigger roots then repairing the foundation.  You would also have to check local regulations as some jurisdictions require you to jump through hoops in order to remove a tree.

I think you were wise to pass on the deal.