How long before weatherproof layer?

[Balthazar]

I completed my vermicrete layer last Saturday and was just wondering when would be a safe time to apply the acrylic stucco weatherproof layer?
I was hoping to do it this Saturday. Would this be too soon (7 days)?

[Dutchoven]

Re: How long before weatherproof layer?

Balthazar
I wouldn't think that is too soon...I say go for it...that vermicrete stays moist for some time which should only help the layers to bond together better!
All the best!
Dutch

[david s]

Re: How long before weatherproof layer?

I don't entirely agree. When you do the vermiculite layer it takes A LOT of water.Given that 1 litre of water= 1000 litres of steam, that can contribute to an enormous amount of pressure on your outer stucco layer. Why not wait at least a week to let the vermiculite layer lose some of its water (you don't need strength here, the cement is only needed to hold the mixture in place) then do your curing fires to eliminate more water, then apply the final stucco. Am I being too cautious ? I don't like cracks on the outershell.

[Johnny the oven man]

Re: How long before weatherproof layer?

My call would be dry it out first then the render.

[Balthazar]

Re: How long before weatherproof layer?

Thanks guys. Well by this Saturday, it will be a week since I did the vermicrete layers, and yes, I did use a lot of water, so perhaps I should leave it another week? That will make it two weeks drying in fair to warm conditions.

[david s]

Re: How long before weatherproof layer?

Have you started lighting some fires in it yet ?

[Balthazar]

Re: How long before weatherproof layer?

Nope...not yet. I thought I would let it dry out, then do the stucco layer, let that dry and then start firing it.