Pumice fireplace liners

[Ron Gries]

Are pumice fireplace liners considered safe today? I inspected a duplex that was built in the 80's. Both fireplace liners are made of pumice (cinder block material). Should I comment on this? I am going to mention that the upper flue needs repointing and that the rain cap is deteriorated.

[wayne soper]

did you take a shot down the flue?
Building a chimney: Topstak chimneys, fires and stoves - Cowbridge, South Wales (http://www.topstakchimneys.co.uk/building.php)

[Scott Patterson]

Is that a pre-fab or cast fireplace and flue? Those are the only ones I have seen that look like your picture.

[Ron Gries]

Fireplaces are prefab. A metal firebox on one side and a prefab with firebrick on the other. The chimney is masonry.

[Scott Patterson]

Fireplaces are prefab. A metal firebox on one side and a prefab with firebrick on the other. The chimney is masonry.

I guess I should have said "cast" masonry. The flue in your picture looks like the "cast" masonry fireplace and flue units I have seen. The whole unit is delivered to the site and put in place. Many times they are dumped off the truck and cracks appear in the flue sections. I forgot their commercial name.

[Bob Harper]

There are several pumice-based chimney and liner systems out there. Isokern is probably the most popular right now. One of the problems with this material is its porosity to water.

Scott, I think you are referring to the Rampart General monolithic cast fireplace and chimneys. These are cast as one homogenous unit, transported to the site flat,then raised with a crane. You can get damage from the transportation, handling and raising operations alone. However, these units have a well documented defect in their calcium aluminate breast plate that always cracks and there is no approved repair method. The entire unit must be torn out of the house and discarded. Dale Feb has one in his training center in Moorpark, Calif. where you can see the fireplace and chimney separtely. He has an entire course on Pre-Cast Masonry Fireplaces.

There has been a resurgence in these cast fireplaces and along with them a rise in problems. The installation instructions are vague which can lead to poor choices in installation. Since this surge started only a few years ago, it will take time to get the word out about these units and flush out most of the problems. I know Dale and I spend a good bit of time studying these units every yr. at the HPBA EXPO and talking with their resepective staffs.

Ron, what do you consider "safe"? Fireplaces are a lot safer if you don't burn fires in them. I think where you need to start is ascertain if these units are listed (UL127) and if not, do they have a IEEE report or similar to where the AHJ has accepted them. You can use alternative construction materials and methods over brick and mortar but the AHJ has final say on local approval. Then, you would need to determine if it was installed to the listed instructions and codes and that requires a trained inspection.

Ron, do you have any pics of these fireplaces?

HTH,

[Ron Gries]

I'm sorry that I do not have any photos of the fireplaces, they appeared normal and in good condition. One is a typical prefab, firebrick lined. The other is a metal firebox, no firebrick.

[John Kogel]

I imagine you've called for an inspection by a chimney specialist.
Firewood is pretty dry where you are. Up in my area, that material would be permeated with creosote and completely unsafe by now, from people burning wet wood. I once saw an unlined concrete block chimney that had an airtight woodstove hooked up to it. After one winter, they actually had creosote oozing out through the concrete.

[Mike S]

I have seen that "oozing" happen before as well. It really makes you think about how much really builds up in there.