Roofing projects are complex, so they are better left to the pros. When a roof is not fixed or repaired correctly, it can risk extensive damage to the whole property and take away the house’s curb appeal. Furthermore, improper installation can lead to concerns like higher utility bills, ventilation errors, and dry rot. If a person still wants to go ahead and undertake the roofing project, they should avoid these six common mistakes. Placing new asphalt over the old layer Placing new asphalt over the previous layer is a big roofing mistake people should avoid when working on renovation plans. New over old might work out well for certain roofing systems, but it is usually the wrong way. Placing new asphalt over the old layer is illegal in some places and more expensive. When installers do this, they risk missing a problem in the old roof, which could lead to higher repair and replacement costs later. Additionally, this practice can lead to the roof structure shouldering more burden than it was designed to. So, individuals should first get the roof inspected and avoid applying a new asphalt layer over the old one. Installing a slate roof without researching While a slate roof demands little to no maintenance, replacing it can be tricky.