The warranty for algae-resistant shingles varies by manufacturer, but the industry standard is 25 years for overall shingle durability and lifespan and between 10 and 15 years for algae resistance. Some products come with longer warranties for discoloration of up to 30 years. Check warranty coverage for the shingle and algae protection before deciding on a roofing product.

Skipping the installation of a drip edge or gutter apron can lead to significant water damage. Without this component, water is more likely to seep under roofing materials or leak behind gutters, damaging the fascia, soffits, siding, and even the interior of your home, such as the attic. Over time, this moisture can cause rot, mold, and deterioration. In colder climates, a missing drip edge also increases the risk of ice dams, which can lead to expensive repairs. A drip edge is an essential part of a roof's drainage system, and some local building codes may even require its installation to protect the home from water damage.

The level of underlayment’s water resistance will depend on the type of underlayment. The most popular underlayment, felt, is water-resistant, but it can’t withstand long direct exposure to rain or the elements. 

Synthetic underlayment is more waterproof, but asphalt is the only fully waterproof type of underlayment.

There are several signs that indicate you’ll need new underlayment. Clear signs include missing or damaged roofing and exposing the underlayment to the elements. Additionally, if you notice water damage in your home by the roof after a storm, it could indicate that your underlayment may need to be replaced. If your gutters aren’t draining properly, it could also lead to rotting or water damage to the underlayment.