Unpopular opinion: I mixed a batch of mortar with leftover coffee instead of water on a cold morning job.

It set way faster than I expected, almost too fast for the chimney repair in Buffalo. Anyone have a better trick for working in the cold that doesn't risk the mix?

3 comments

3 Comments

torres.drew1mo ago

So you basically made a caffeine patch for your chimney? Bet it won't sleep for a week.

quinn_nguyen1mo ago

Whoa, that sounds like a recipe for trouble. Coffee's acidic, and that can really mess with the chemistry of the mortar. You're lucky it set at all instead of just crumbling later. For cold weather, you gotta use an antifreeze admixture made for masonry, or just warm the water and sand first. Anything else is asking for a call-back.

alice_reed471mo ago

Yeah, and even if it seems fine now, that acid could eat away at it over years. I saw an old patio where someone used vinegar in the mix, and it was just powder in some spots. Warming the materials is the safe bet, but you really need to keep it above freezing for a couple days after too. What a mess to fix later.