The answer to your question depends on what kind of texture it is in the first place. Look at the bottom left hand corner of the Texture Component in the Materials Lab. You will see a T and a P. If the T is lit up (and it can be hard to tell the difference) you are dealing with a Procedural Texture. If the P is lit up, you are working with an Image Texture. If you can't tell which one is lit up, click on the second button from the top left corner. (The text area above the palette will say "Texture Source Editor" when you are over the correct one.) If you find yourself in something called the Deep Texture Editor, you are working with a Procedural Texture. If you find yourself looking at a Pictures dialog, you are working with an Image Texture. Procedural Textures cannot be distorted by changing the shape of the object. However, sometimes they are 1D or 2D textures, not 3D textures; so the texture appears correctly on only part of the object. If this is the case, let me know and I'll tell you how to fix it. Image Textures can be distorted. In that case, as explained by Tuttle, you need to change the proportions of the image. Be careful, though. If you like the size of the bricks on the front just multiply that number by the difference in size (3 in Tuttle's example.) Otherwise, you will change the size for all the bricks. The closer the percentage number is to zero, the larger your bricks will be. The farther from zero (either as positive or negative numbers) the smaller the bricks. Also, in order for this to work as you expect, you might need to change the mapping mode to Object Cubic. (Especially if it's at Parametric right now.)