Hearth: plastic cover instead of burlap?

[sarah h]

My insulating hearth is now poured .
I saw some posts stating that it should be covered in burlap for a few days and think I remember one that said plastic sheeting would do too, but couldn't find it again to be sure. I don't have any burlap so it now has a plastic covering. Is that OK , since it is not breathable like the burlap, or should I remove it?

Sarah

[asudavew]

That should be fine.

The point is to NOT let the concrete dry out.

Cement needs the water to completely cure. If the water evaporates the concrete won't completely hydrate. Hence, it will be weaker.

so keep it moist for a least a few days.

[Unofornaio]

I think you may have gotten mixed up..easy to do, lots of things to read and remember.

The hearth slab (concrete) when poured separately should be kept covered with burlap or kept moist to slow evaporation of moisture in warm or hot weather. This should also be done for the slab on grade when its very hot outside.

The insulating layer (vermiculite, Portland) should not be subjected to water at this time. DO NOT PUT WATER ON IT. If you have poured them a day or so apart as many do this is perfect, the insulation layer contains a lot of moisture which keeps the slab moist although not really an issue this time of the year. Its not a good idea to cover this with plastic as it needs to dry out more than cure like a concrete mix does. The vermiculite holds a tremendous amount of water so keeping this layer moist is not necessary. If you expect rain cover it, if not, keep it uncovered.

[asudavew]

I read hearth.

Not insulating hearth.

So in that respect.. I covered my insulating hearth for a couple days.

But it stays in the 90's to 100's around here, and it's dry. So stuff dries out quickly.

But Uno's advice sounds perfect for you.

[sarah h]

Thanks for the info and sorry for the delay in saying so - my modem died and I just got up and running with the new one.

I removed the plastic cover but tarped it loosely, still allowing air flow, to keep off the rain that has been here all week. All in all, it has hardened right up and seems (somehow!) to be drying out.

I'm looking forward to playing with bricks this weekend .

Sarah

[asudavew]

Originally Posted by sarah h

I'm looking forward to playing with bricks this weekend .

Sarah

Let the fun begin!