Fireplaces are a great thing to have, but they can be quite difficult to maintain and repair--especially if yours is more than a few decades old. Luckily, there are plenty of products out there that are designed specifically for fireplace maintenance and repair. One such product is refractory mortar, which is relatively inexpensive and can help you fix up your old fireplace.

How Refractory Mortar Works

Many fireplaces (particularly newer ones) are laid in Portland cement mortar. While this type of mortar is certainly strong, it is not designed to resist the constant high temperatures that fireplaces can produce. Luckily, most people don't use their fireplaces as the sole heating device for their home. They only fire them up occasionally, which the mortar in their fireplaces can handle--at least for a few years.

When the mortar in your fireplace starts to fall apart, it may be necessary to patch the fireplace or even rebuild the whole unit. In either case, refractory mortar is the best product to use. Refractory mortar contains sodium silicate, which acts as the binding agent. Unlike other types of mortar, refractory mortar does not deteriorate when exposed to high temperatures.

Like firebrick, refractory mortar actually gets stronger when it is heated. It responds to heat with a ceramic set, which makes it ideal in situations where mortar will be exposed to constant high temperatures. Refractory mortar is also non-water soluble, so it will not wash out inside a chimney if exposed to rain or water.