The answer to 'my roof installation is failing' is that there could be several common causes, including improper installation, poor quality materials, or damage from weather and environmental factors. Symptoms may include leaks, sagging, missing or damaged shingles, and premature wear.
If you're experiencing roof installation issues, it's generally best to call in a professional roofing contractor to diagnose and fix the problem. Roof work can be dangerous, and trying to DIY repairs without the right expertise and equipment can often make the problem worse or create additional damage.