Sealants

Any time you are mounting a mast to a structure, each penetration must be sealed to keep water out. There are two primary sealants used to accomplish this.

For asphalt shingles, the material to use is known as Bishop tape. Another term for it is pitch patch. It is a thick, black, tar-like substance that will adhere to the shingles and create a water-proof seal. In cooler temperatures it does not adhere as well during installation but still results in a good seal. In warmer/hot temperatures it will stick rapidly, making re-positioning difficult. The Bishop tape is installed directly on the asphalt shingles with the lag bolts screwing through the mast holes and the tape to form the seal.

Clear silicone is used to seal all other mast penetrations. This is used for each penetration/lag bolt independently.