The lifespan of asphalt shingles is typically between 15 and 30 years, depending on the type of shingle and other factors. Standard 3-tab shingles have the shortest lifespan, around 10 to 15 years. Architectural shingles last longer, averaging 20 to 25 years. Luxury or designer asphalt shingles are the most durable, with a lifespan of 40 years or more. Climate, installation quality, and regular maintenance also play a significant role in how long your shingles will last. Signs that they need replacement include granule loss, bald spots, and roof leaks.

Condensation can occur on the inside of a roof, but it should always be temporary. It does not necessarily mean there is a roof leak. Condensation happens when the inside and outside of a house are at different temperatures. For instance, if it is hot during the day and then gets very cold at night, the inside of the house will be warmer than the outside and may cause condensation to form on the inside of the attic. This may not be cause for concern, but if it is happening frequently, it should be addressed; otherwise, it could cause roof leaks, compromise the structural integrity of the wood, or allow mold to grow.

Yes, an underlayment is required for metal roofs, especially when installed over an indoor residential living space. This underlayment acts as a protective barrier between the metal roofing and the roof deck. Common materials include tar, asphalt felt, or woven synthetic polymers. Depending on local building codes, existing shingles in good condition may also suffice. A quality underlayment is crucial as it provides protection against water intrusion, improves energy efficiency through insulation, helps absorb sound, and ultimately extends the lifespan of your roof.

You shouldn’t put a new roof underlayment over an old one for a few reasons. Old felt must be removed in order to assess the condition of your roof decking, such as rotting wood or other structural issues. Also, if your roofer doesn't install a fresh layer of felt as is required by shingle manufacturers, your warranty may be voided. Finally, old underlayment removal is often included in the cost of roof repair or replacement, so there's no real benefit to leaving it on before installing a new layer.