Before you start
<h2>1. Confirm the source</h2><p>Use a strip of tissue to locate air movement. Do not use a flame.</p><h2>2. Clean and measure</h2><p>Clean the stop, let it dry, then measure all three sides. Cut compressible weatherstrip without stretching it.</p><h2>3. Test the latch</h2><p>Close the door slowly. The seal should compress evenly and the latch must engage without force.</p>Confirm local rules and stop if the work affects gas, fixed wiring, structure, roofing or hazardous materials.