Insulating hearth question

[rwiggim]

I can't imagine trying to build this without all of the help in this forum. Thank you all. Luckily I read a thread yesterday about the techniques on working with perlite and concrete before I added as much water as I would have the day before.
My question:
I have it level with the top of the form but there are spots where the layer is flat and smoothish but others where it is a little like ceiling popcorn. I tried to tamp it down but I guess some spots had more moisture than the others? I have attatched a couple images that show the lighter grays as the smoother spots. Would I adjust for this with a slightly thicker layer of Fireclay/sand to fill in the popcorny spots?

Thanks again and if you find yourself in Portland anytime soon....
darren

[JoeT62]

Re: Insulating hearth question

It looks EXACTLY like mine did. As you spread the fireclay/sand mix it will fill in where it needs to, and glide over the other spots. The important thing is to get a nice level surface to lay the cooking floor on.

Nice job!

[RTflorida]

Re: Insulating hearth question

Agreed....mine looked the same, Although I took a slightly different approach to the fireclay/sand mix.
Since I wasn't using fireclay anywhere else in the project and I was too lazy to make a special trip for just a few lbs, I used a slightly wetter mix of Heastop 50 as a very light skim coat to smooth the perlcrete and then used a 1/8" grooved trowl to apply the same mix to set the hearth bricks on...tapping and leveling as I went. I wouldn't say my hearth is mortared in place, just "glued" enough to hold them in place and level. No adverse effects from this approach that I have found.

[rwiggim]

Re: Insulating hearth question

thanks. I always like to hear that I might have done something correctly.

[Dutchoven]

Re: Insulating hearth question

Looks like standard issue vermicrete to me. There should be a bit of slip between you floor and the floor bricks anyway. You could lay a thin coat fireclay sand over it to make it smoother but, it really shouldn't be necessary to do it as an extra step as the fireclay slurry will do it when you lay the floor bricks. Looks like you're doing a fine job! Keep up the good work!
Dutch