Question
Ww planted a bald cypress ten years ago. It is about 35 feet tall an ten inches in diameter at the base.  The knees and or roots are visable above the ground all over our yard, mostly haven been mowed down to close to level.  The heighbor's home sets about twenty feet from ours in a normal type subdision in Pearland, Texas.  The annual rainfall here is the same as Houston, Texas, as we are basically a suburb, which means alot of rain, very humid, with perhaps week long dry periods,  The knees have come about a foot from his foundation and about an inch tall.  The same with the ones I can see in our flowerbed in front of our home.  Is this tree root system gooing to invade and destroy our foundations and what can we do.

Answer
It could damage the foundations. You can install barriers along the foundation to stop the roots. Sounds like the tree is too close to the house. Bald cypress can grow large  50 to 70 feet in height with roughly 30 foot spread with the roots spreading to about 45-60 feet from the trunk. The "cypress knees" usually only develop when grown in or near water for most of the year. In wet soil conditions, the bald cypress will form sections of root growing above ground to gather oxygen. Since they grow in water the roots will seek water and grow toward a good water source.
If the roots are ruining your foundation I am sorry your best bet is to remove the tree. The roots will sprout from a cut tree. I would treat the stump when you cut the tree with a herbicide called Roundup. The Roundup will be taken up by the stump and transported to the root system killing the system. That way there will be no new sprouts coming from the roots. Roundup can be found at any nursery/ garden type store. Roundup will kill any plant so make sure you do not get the mixture on any leaf of a plant you do not want to kill. I would get an old paint brush and paint the stump with the Roundup that way a spray will not be carried by the wind to adjacent plants. Throw the brush away after you finish.