Roofing is an important part of construction and renovation. It involves installing a roof, which is necessary to avoid damage caused by water and other environmental factors. Improper installation or mistakes while replacing and installing a new roof can lead to further damage, eventually compromising the structure of the house. This can end up costing one even more. So here are a few common mistakes that should be avoided when installing a roof: 1. Laying new shingles on old ones When installing a new roof, one of the biggest mistakes to avoid is laying new shingles on old ones. Doing so can leave gaps where water and dust might begin collecting on the roof. Over time, this can damage the roof even quicker, requiring the homeowners to shell out even more money to repair their roof. Plus, if there has been a lot of damage due to water and dirt, homeowners may spend more than they initially did. Removing the old shingles before installing the new ones is vital to avoiding these hassles. 2. Failing to lay shingles on the overhang correctly The next aspect to take care of when installing new shingles is to secure them properly at the overhang.