Kohanim Not Becoming Tameh

From Halachipedia

Blocking Tumah of Corpse

  1. If there is a corpse in a room the tumah extends from room to room if there is an opening of a Tefach by a Tefach. If there is an opening of a Tefach square and it is completely closed off tumah doesn't extend beyond. However, if it is only partially closed off and the hole is less than a Tefach if the closing is permanent the tumah doesn't extend but if it is temporary it isn't a sufficient blockage and tumah expends.[1]
  2. A closed door is considered a permanent blockage of tumah.[2]
  3. Only items that aren't mekabel tumah are able to block tumah.[3] Anything attached to the ground isn't mekabel tumah for these purposes.[4]

Sources

  1. Shulchan Aruch YD 371:1
  2. Neeyim Zemirot p. 49 writes that a door can be a stimah olamit but if it is metal there's room to be machmir since it is mekabel tumah. Avnei Nezer OC 293:7 holds that a door is a stimah forever but struggles to prove this. Taharat Hakohanim 371:14 quotes the Avnei Nezer as primary.
  3. Rama YD 371:1
  4. Taharat Kohanim 371:19 quoting Kehilat Yakov Taharot 25