What to use to make fake lava rocks?

Does anyone have a suggestion of what to use or how to make fake lava rocks to cover a fireplace? I checked out real lava and I think that it will be too heavy. I am also considering Plaster of Paris but wasn't sure if it was the right way to go or really how to do it if it was.

A fireplace is suposed to be made of heavy stuff. There are tons of glues as well as old school morter that work well on Lava Rock...

If this is a prop fireplace, you might be able to make some fake rocks by using foam (either pre existing or the two part marine mix)paint them black and just glu them to the existing fireplace stone.

They will of course burst into flames if they get hot tho.

Is this for your house?

Yes, for our house. You are right it should be flamable.

If it's sticking to existing brick or cinderblock, you should be able to just attach them with masonary adhesive, or morter. The weight won't matter. Clean the old stuff really well, and if you use morter soak the rocks. (Black lava rock when indoors shows dust really badly with all the nooks...be warned)

I've seen rough black fired brick too both real and the inch thick fake stuff that people attach to stucco. This might be an option.

Agrigate places usually have an assortment of stone you can just purchase by the yard. They will let you sort of pick what you if you pick it up yourself.

If you are dead set against using actual rocks, some industrial tile places also might have somthing you could use which wasn't intended for that.

Another angle might be to do a bit of exparamenting, and try lathing the look you want, to the reinforced exsisting fireplace, then texturing the applied material while it's wet.

aloha,

check out these threads, they may be of assistance:

Fake Lava Rock Progress Pictures:
http://www.tikicentral.com/viewtopic.php?topic=8649&forum=7

Fake Lava Rock....Advice Please!:
http://www.tikicentral.com/viewtopic.php?topic=8218&forum=7

Hope that helped