Round shape

[Mike D]

Re: Round shape

I was thinking of pouring a vermicucrete layer to go under the ceramic board for a double insulation (I know over kill, but keeping the floor hot is the name of the game right). The mix in the plans call for 5 to 1, this is done by volume? As in 2 (4 cf bags) and 2 90lb bags of portland cement?
Any one have a good way to measure these?

Mike

[GianniFocaccia]

Re: Round shape

Mike,

I like your idea of compound insulation. For my build I installed 2" of Insblock 19 on top of 3 1/2" of (wet) vermicrete. I measured my 8-1 vermiculite into a wheelbarrow with 5gal buckets and dissolved the portland cement in water prior to mixing it into the dry vermiculite. This was a simple and easy task to do gently with a hoe. After leveling the vermicrete with a wood hand float, I tapped the board onto the surface and viola!

John

[Mike D]

Re: Round shape

Why 8-1. I have read people do 6-1 and the plans say 5-1. Was that dry? Did it hold it's shape? I like the idea of putting on the board when its wet to connection and make sure it is level.

Mike

[dmun]

Re: Round shape

8 to one is a slurry based method. 5 or 6 to one is when you mix the dry ingredients and add water, which is what I did. Both methods work.

Putting the boards down into wet concrete is a good idea. I did this, directly on my support slab. The only warning is about doing this with cal-sil boards, which aren't used much any more. They tend to behave oddly when wet on one side.

[david s]

Re: Round shape

If you use more cement, the mix will give you a stronger slab, but it won't insulate as well. The reverse is that a weaker mix will insulate better but not be as strong. Your decision.

[Mike D]

Re: Round shape

So how do you measure the volumes? Before the cement is mixed (dry) or with the water (wet)?

Does anyone have a cubic foot to dry portland ratio?

Mike

[Neil2]

Re: Round shape

"Does anyone have a cubic foot to dry portland ratio?"

I would put it in the order of 0.5:1 (water to portland) by weight.

Having said that, there are too many variables to get an exact ratio (relative humidity, moisture in aggregate etc.)

If mixing dry, add water sparingly until desired consistency is reached.

[Mike D]

Re: Round shape

Sorry Neil, I don't think I am asking the right question. You are right the water will very. What I wanted to ask was the vermiculite to dry portland ratio. As in if I use one 4 cubic ft bag of vermiculite how much dry portland cement do I use for a 6-1?

Thanks for the help guys.

Mike

[GianniFocaccia]

Re: Round shape

Mike,

Prior to mixing, I measured the respective dry ingredients separately, placing the vermiculite in a wheelbarrow, and the portland in a bucket. I then added the portland slurry to the wheelbarrow and while gently mixing with a hoe, added water from a hose just until I got a workable consistency.

Having read of FB builders going with ratios from 5:1 to 12:1, I went with 8:1, right down the middle. As a test, I placed the leftovers in a bucket and let it dry. Then I pulled the 2" thick 'disk' out and pressed down on it with my thumb. It didn't budge. I could crumble the edges off, but a 20lb dumbbell placed on it didn't compress it at all.

Before I began my backyard project I had no practical masonry/wood cutting/building expertise. The beauty of this forum is that I have now learned to go inexperienced into each new construction phase/element with confidence that it will work out and it always does. Just go for it.

John

[david s]

Re: Round shape

Mike,
If you are mixing 6:1 that is 6 parts vermiculite by volume dry and 1 part dry cement powder. I've found the best way to mix it is to combine the dry ingredients and mix them until the colour is consistent then add 3 parts water by volume for every 10 parts vermiculite. If you end up adding too much water it will take the cement slurry to the bottom of the mix resulting in an uneven mixture. I think it is also better to leave the vermicrete slab for a minimum of one week with sun and wind, to dry out before building over it because it is difficult to remove the moisture from it later, when it is covered.

[Mike D]

Re: Round shape

-Thanks David s- I will give it a go this weekend

-GianniFocaccia thanks for the Help. I was looking over your build, I am planing on having a round arch for the front (like keweb and sjmeff). My wife's sister lives in La Mirada, been there a few times.

Mike

[Wiley]

Re: Round shape

Why does a bag of portland cement weigh 94 lbs?

answer: That is the weight of one cubic foot of cement.

Or stated another way: Cement is sold in bags that measure one cubic foot which happen to weigh 94 lbs. Most (always hesitant to say all) concrete measurements are done in volumes.

Hope this helps,
Wiley

[Mike D]

Re: Round shape

-It's been raining here off and on, didn't have time to pour the vermicucrete layer. I did pick up my bricks and have been playing around with the floor. The HF saw is nice but the slide gets a little sticky if you don't push it just right. Do you need to grease the wheels?

-Here are a couple of picks of the slab with out the frame, and a dry fit of the grill (the floor will have loose fire bricks).

[brickie in oz]

Re: Round shape

Love the bricks, nice orangey/red colour.

The saw sliding table should push easy, there is probably a lump of crud stuck in the wheel grove. (assuming the wheels have a groove as the have here)

[Mike D]

Re: Round shape

I poured/made the vermicucrete layer. That mix is not normal. But it seemed to work.
-Do I keep it wet/spray it down?
-Do I keep it covered or let it dry without a piece of plastic over it.
-You don't float this thing do you? It doesn't seem like it would work if you did.

Mike