Guide
Tayammum: Dry Ablution When Water Is Unavailable
Tayammum is a dry form of purification that stands in for wudu (or the full bath) when water is genuinely unavailable or its use would cause harm. The Qur'an grants it explicitly as a mercy, so that the absence of water never prevents a believer from praying on time.
When it applies
Tayammum is permitted when there is no water within reach, when the available water is barely enough for drinking, or when using water would worsen an illness or injury. Once these conditions pass — water is found or health is restored — one returns to ordinary ablution.
How it is performed
Form the intention to purify for prayer, then lightly strike or place both palms on a clean natural surface such as earth, sand, stone or dust. Wipe the face once, then wipe the hands and forearms. The schools differ on the extent — the Hanafi view wipes the arms to the elbows, while others wipe to the wrists — and on how many strikes are needed; each position is well established.
What it allows
A valid tayammum permits everything wudu would: praying the obligatory and voluntary prayers, and touching the Qur'an, in the same way. It is a complete substitute for as long as its excuse lasts.
What nullifies it
Tayammum is broken by anything that would break wudu, and also by the removal of its cause — most importantly, the availability of usable water. At that point ordinary ablution is performed again before the next prayer.