Same day pour?

[jaymac2087]

Hello all,
I am getting ready for my hearth pour tomorrow. Just have one question, can I pour the vermicrete layer right after I am done screeding the structural layer? Any advice would be great.
Thanks
Jay

[dmun]

Re: Same day pour?

Yes, you can pour both the same day, but that's a lot of work, there's no need to do both the same day if you're exhausted after mixing and lifting that much concrete.

[RTflorida]

Re: Same day pour?

As dmun says, you can but it is not necessary. "Back in the day" the original Pompeii plans directed you to a same day pour. The thinking was the layers would bond together better. This has been found to be unnecessary, the vermicrete is not going anywhere with the weight of the oven sitting on it.

I did a same day pour and foolishly mixed it all by hand...damn near killed me.

RT

[jaymac2087]

Re: Same day pour?

Thank you for the input. The only reason I am going to do a same day pour is because I have a concrete mixer for the day a couple of friends who are willing to help. I just wanted to make sure ther would be no problems with pouring one right after the other. Thanks again.

[dmun]

Re: Same day pour?

There's some concern that a concrete mixer will compress the vermiculite/perlite. If you use it, mix the portland/water slurry first, then just mix in the aggregate until it's just wet.

[jaymac2087]

Re: Same day pour?

Dmun,
What would be the best way to figure out the vermiculit to portland mixture?
I plan on mixing it by hand and just using the mixer on the structural layer.
Thank you for such quick responses.
Jay

[Neil2]

Re: Same day pour?

"There's some concern that a concrete mixer will compress the vermiculite/perlite."

I agree with dmun. A concrete mixer will break down the vermiculite particles. Mix the vermiculite/perlite layer gently by hand in a wheelbarrow. This is very light material and the mixing is easy. I suggest a 6:1 ratio (by volume) for the insulating layer between the suspended slab and the hearth bricks.

[ThisOldGarageNJ]

Re: Same day pour?

I used the #2 med grade vermiculite, In a mixer, I mixed the vermic and portland dry then added water till it got like oatmel, I had read after I did it not to use a mixer but it was too late....What happened,,, Nothing,, my oven will hold 300 degrees for 2 days if I leave the door on, If I leave it off, its still 200 or more the next morning. I may have just been lucky,, but its working fine, I bought a mixer from HF for 115.00 (small one) mixes a 80 lbg. bag of premix, They wanted 65 to rent one, so it was worth it to me even if it broke after I was done... I have mixed at least 75-100 bags with it so far, I just tarped it saturday as I think im done mixing till spring..
Cheers
Mark