If you have a crack in your home's foundation, it is important to know if it is horizontal or vertical. Cracks that run more or less vertical and that are not more than 1/8-inch wide are probably not cause for alarm. If they are horizontal, however, there could be a problem. If it has misaligned edges or has movement, it might require a professional check-up. You should monitor it by marking off the ends of the crack and making several ?alignment? marks across the crack at various points. Then check it periodically. If the crack gets longer or the marks become misaligned, it's cause for concern. And that's the On The House tip for today.