very good for fireplaces and wood ovens the only slight problem is that it needs 6 days without lighting a fire that is, the temperature should not rise because if it does, it will not dry evenly and later it will create 100% cracks in the glue and there is a high risk of the firebricks coming out of their place (falling) so... you put it, leave it for 5 to 6 days and it will last you for years, the manufacturer also states this on the packaging. do you want a proper job once and for all? wait if you don't want it? light it before the 5-day mark and every 10 days you will need cement and repairs