DAP 7079818854 High Heat Mortar Fire Stop Caulk, 10 Fluid Ounces, Black

I have used this product for the past 30 years. My home is 50 years old. Overtime mortar becomes cracked and worn away. This is a necessity for protecting your fireplace from gaps inside. It works well.

Bought this to lay around my pipe for when things get hot. Set up well and withstands the heat.

I recently purchased a 37 year old house with a fireplace that was in need of repair. I received a quote to repair the cracks from the provider who cleaned the flue, and it was going to cost around $200. I purchased 2 containers of this DAP mortar and did the repairs myself. I only ended up using 1 container, which went further than I expected. It is pretty much like working with any other tube of caulk. Many of the cracks were fairly narrow, so I only clipped a small amount of the end off, so that I would be able to fill in those narrow cracks. It was fairly messy, though I am not very skilled with apply caulk, so that was to be expected. It dried fairly quickly and I was able to start a low burning fire (i.e. 2 small logs) within 2 hours after applying the mortar. The color of the mortar is black, and as far as I can tell, the color doesn't change. We plan to paint the inside of the fireplace black, so it is not an issue for us, but otherwise, the color might be an issue for some. I've included some before and after pics, showing the cracks before the repair and the black mortar after the repair.

Used to fill in fireplace to wall gaps. Took care of wind noise

The media could not be loaded. I got scared away by other brands due to their reveiws so I picked the cheapest option and i am beyond happy. There's no more smoke pouring out of my chimney and there's no smell! It did bubble up but I got the fire a little too hot and im not concerned about what this looks like

I used it to seal around a fire pit. After several uses, it started to Crack and flake off in chunks.

This worked great.

worked

Worked great for me.

Worked well for what I wanted. I needed to seal between the bottom metal edge of my fireplace grate and the irregular surface of the stone hearth. I was expecting that it would be firmer out of the tube and hold its shape better. I needed to tape off what I needed and let the product dry, which it did quickly. It has hardened now and fills my gaps very well.

Used this to repair some minor cracks and a few small broken areas of mortar in my fireplaces. It is a bit sticky, sometimes preferring to stick to the tube and to fingers rather than to the mortar, thus it was a bit more difficult to apply than I had expected. However, overall it has stayed solidly in place after several fires in the fireplace, and it looks good.

Followed the instructions perfectly but the seal gave away just after two days.