Purity: Jabirah Covering a Limb or Most of the Wudu Parts
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 329:
If the jabīrah completely covers one of the parts of the body on which wuḍūʾ is performed, then performing jabīrah wuḍūʾ is sufficient. However, if the jabīrah covers all or most of the parts of the body on which wuḍūʾ is performed, then based on obligatory precaution, one must perform tayammum and jabīrah wuḍūʾ.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)