I saw that the chimney sealant crumbled and crumbled. Is there any point in using it then? I am trying to solve the problem.

In all the descriptions for the installation of chimneys that I have met, the use of high-temperature sealant at the joints is mandatory. And of course I followed the recommendations. But this sealant is not like a sealant at all ...

Friends, I am glad to welcome you. Among the wide variety of sealants that are currently on the market, you can find any that meets the requirements for a specific task.

Depending on different operating conditions, its properties must be preserved for the main task - sealing.

I thought so until I met this ...

Here is a high-temperature sealant that I used when installing a chimney in my house.

Designed for 1500 degrees, the manufacturer is well-known. There was no reason for doubt.

• I missed all the pipe joints with it, and I was sure that everything was sealed and reliable there now ..

• Then I decided to use it to cover up the cracks in the chimney passage through the wall.

But the picture that I saw a few days later surprised me, to put it mildly.

• This is what this seam looks like now.

• The sealant is dry and cracked.

Simply, in my opinion, a sealant is something elastic (like rubber). Otherwise, how can he seal something?

It turns out the sealant has nothing to do with it.

Or rather, this is its property. And all high temperature sealants (which are black, more than +1000 ° С) will harden.

✅ But how can its use be called sealing, I do not know... Indeed, when the chimney heats up, the metal will expand, and cracks will appear. It's like sealing with cement.

But it's probably better than nothing, there will be some kind of sealing of the joints.

And if elasticity is needed, then a red sealant will do.

Its temperature threshold is about 300 ° C, and it remains elastic (in cars it is used as a replacement for gaskets), which of course is not suitable for internal sealing of the chimney. But for me, to close the gap between the sandwich and the wall would be just right.

Friends, what do you think on this issue? Share your experience and give advice. It's always good.

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