This item was used to replace the brick in the chimney. FOLLOW the instructions to the tee and this product still failed. Started curing at low temperature (1 Log Duraflame) after being allowed to dry for over 28 hours and it bubbled and the bricks separated. Now I have to make it complete, but this time with real chimney mortar. I didn't follow the advice of others, so don't repeat my mistake. Do not use it to install brick or use Rutland products as they are cheap, counterfeit and unfit for use in your fireplace. Check out the local brick makers in your area and buy real mortar for the job. Do not put yourself or your family at risk by using this product because if it doesn't fail right away, it will eventually!