The answer to 'why is my underlayment clogged gutters' is that a clogged gutter can cause issues with the roof underlayment. The underlayment is the waterproof barrier installed beneath the roof shingles, and when gutters become blocked, water can back up and seep under the shingles, saturating the underlayment. This can lead to leaks, rot, and other serious roofing problems.
Common causes of clogged gutters include debris like leaves, twigs, and dirt buildup. Symptoms may include water overflowing the gutters, stains on the siding, and damp or rotting fascia boards. To fix the issue, you'll need to clear the gutters and ensure proper drainage. This is usually a DIY task, but for extensive damage or if you're not comfortable working on the roof, it's best to call a professional roofing contractor.