LOCTITEPL500 Landscape Block & Stone Adhesive, 10 fl oz, 12, Cartridge

Q: Can i use this product for a brick firepit

I used it on a brick wall around my patio and it worked perfectly to hold the loose brinks, but it does not appear to be able to handle high heat. The company had this to say about using it in fireplaces and fire pits (on the company website): The Loctite PL 500 is not intended to be used on or near fire places where high heat is possible. This product is a synthetic rubber which will soften and fail starting around 150°F (66°C). The PL 500 product is not intended to be a substitute for thin set or mortar applications in this situation.

Q: how long in advance should I apply before it rains?

Tube says, "Outdoor adhesive, bonds wet or dry." I use on patio steps every few years if/when some loosen. It's important to clean sand, dirt etc off bricks before applying the adhesive, though I've always used in dry conditions.

Q: If this adhesive needs to be reapplied how difficult is it to remove the old adhesive?

Very difficult.....the problem is running the risk of damaging the original material. If material is brick or stone or thin veneer type stone I would not attempt to remove it once the adhesive has cured.