Plywood for concrete forms

[Rock knocker]

You were the first person to use the word "cement". The nitpickers on this thread may point that out to you in a negative way!!!

Nope, my usage was absolutely correct. Concrete is a product of various aggregates and hydrated lime cement. I was giving the formula from the hydration of cement.

 

[ovrszd]

Nope, my usage was absolutely correct. Concrete is a product of various aggregates and hydrated lime cement. I was giving the formula from the hydration of cement.

Didn't say you weren't correct. Your statement implied that the hydration of cement was the same as the previous discussion of hydration of concrete.

 

[Snobdds]

That the product is CaO.2SiO2.4H2O, which is a hydrous material

Anything is hydrous material until dry or cure.

lol...

Add a little lime and Portland to mud, and your definition works. But is that really concrete?

 

[Rock knocker]

Didn't say you weren't correct. Your statement implied that the hydration of cement was the same as the previous discussion of hydration of concrete.

The hydration of cement is the only hydration that takes place during the creation of concrete, so they are the same thing. The sand and rocks do not hydrate.

 

[Rock knocker]

Anything is hydrous material until dry or cure.

The formula shows that the water remains and is part of the molecule that is hydrated cement. Just like mica and amphibole are hydrated minerals.

 

[ovrszd]

The hydration of cement is the only hydration that takes place during the creation of concrete, so they are the same thing. The sand and rocks do not hydrate.

I think you just made Snobdds point.

 

[kcflhrc]

Man, this got stupid

 

[Rock knocker]

I think you just made Snobdds point.

No. He doesn't understand hydration at the molecular level

 

[Snobdds]

No. He doesn't understand hydration at the molecular level

lol. Ok Mr. Expert.

 

[Rock knocker]

lol. Ok Mr. Expert.

And your chemistry CV is?

 

[Deere Dude]

I am not a chemist like everyone else on this spiraling out of control thread, but I put a roof on a storm shelter located in my garage. I used 3/4 treated plywood and after a little bracing I poured an 8" thick x 8'x8' slab as the roof. There was no way to get the plywood out after the fact. It has been 3 years and still looks like new. I did throw some screws into the wood to hold it to the concrete just in case it would sag in the center.

 

[ovrszd]

Mab, this got stupid

Intellectually so.

 

[downsizingnow48]

It takes a lot of bracing to form a wall using plywood.

 

[Wood_Butcher_Dav]

I used sub-floor material as the bottom of my concrete storm shelter roof.


Dave

 

[Deere Dude]

It takes a lot of bracing to form a wall using plywood.

After building a small number of walls using 20 sheets plywood and having to buy tons of 2x4s I found out that every piece of wood got sucked into the system anyway. A lot got reused for other concrete walls, a lot got used for shelving in the garage and barn. It all got used up someplace else so it was not all money down the drain.

 

[downsizingnow48]

After building a small number of walls using 20 sheets plywood and having to buy tons of 2x4s I found out that every piece of wood got sucked into the system anyway. A lot got reused for other concrete walls, a lot got used for shelving in the garage and barn. It all got used up someplace else so it was not all money down the drain.

Yep it can be used again definitely. Also, other side of the formed wall looks the same. With lots of form ties to hold them together. Just wanted to offer OP an idea what is involved. Concrete will bulge or even knock down the form if given a chance. Better safe than sorry.

 

[turnkey4099]

It takes a lot of bracing to form a wall using plywood.

Or cross ties between the walls, Forms for my patio retaining wall (6!x4'x24' consisted of 2x4 lengthwise top and bottom, a few vertical 2x4 and a lot of 'snap off' cross ties.

 

[bunyip]

We have a product called Formply, it is a black coated plywood designed for concrete formwork, I'm sure you would have the same thing but probably with a different name.
Have used this for various tasks not relating to concrete and the last one was for a new ramp on a horse float.

 

[downsizingnow48]

Or cross ties between the walls, Forms for my patio retaining wall (6!x4'x24' consisted of 2x4 lengthwise top and bottom, a few vertical 2x4 and a lot of 'snap off' cross ties.

Yes to snap ties. The photo I put up shows lots of snap ties connecting the walers.

 

[Streetcar]

I think you just made Snobdds point.

SnobDds is completely wrong. Rock crawler is correct, the cement hydrates in the concrete while water is incorporated in the new compound. Water does not evaporate, except the excess which is not needed in the chemical reaction