Block wall questions

I'm getting ready to lay some blocks. Probably a lot of them, and quite a few mixers full of cement. Some low decorative walls, walkways, pavers, bricks, etc.
For block laying, should I buy a quantity of sand, lime, Portland, etc.? Or should I just go with the premixed bags at the borg? There may be a slight storage problem of unused materials from batch to batch.
Other questions:
Is premixed concrete with aggregate best for first coursing? How about cell filling for grouting final wall?
What should I use for a stucco covering on it? Is that the same mortar mix, or a special stucco mix?
What outdoor temps should block be laid at? And will it matter if the night time temperature is below freezing? Down to about 20 deg. F.
I don't think there will be many complicated things about doing the type, quality, or amount of block work I want to do. But suggestions are welcomed.
Steve
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Steve B wrote:

I don't know why you think you'd need to buy lime separately. Regardless if you're looking for cement or mortar-mix, it all comes in one bag. Just add water, sand (and stone if you want concrete).
I'm not sure if you want to make mortar (for bricks/blocks) or concrete - or both. I've never had the need to make mortar - if I did I'd just as soon use the same portland cement I use to make concrete but just not add any stone to the mix. Or I might do a little research to see if or why real "mortar mix" is better than ordinary portland (type II) cement.

Are these regular construction blocks - concrete masonary units? 8" x 8" x 16" ?
I wouldn't think that you would want aggregate (stone) in your mortar mix for application between blocks. Now, I don't know if you plan to fill the space *inside* the blocks with concrete - if so then yes, we're essentially talking now about concrete and not mortar.

Cell filling and grouting is two different things. I'm sure there are books or on-line guides how to make a CMU block wall. I don't think you're going to put aggregate in the grouting (mortar) mix. That would just turn it into concrete. (to me, mortar or grouting is just cement and sand. Concrete is cement, sand and stone.)
Lafarge makes something called "BlockSet" for this.
http://www.lafargenorthamerica.com/Pozzblends%20-%20PBPOZZE.pdf

I think what you want is called parging mix.

I would never mix or place concrete / mortar below 40f, but that's just me. The pro's that do this have blankets and heaters or otherwise make sure the temperature of their projects don't fall below freezing (and ideally don't fall below 35F).
Curing concrete / mortar when the ambient temp is within a few degrees of freezing is just asking for trouble. It's critical to the hydration process that the water component in the concrete / mortar not freeze before it completes. This is less critical for mass concrete (ie - driveway or some other massive amount of concrete) because it gives off it's own heat of hydration. You won't get as much heat from grouting / mortar application.

Totally nuts. Way too cold.

If you're going to mix your mortar / concrete and set your blocks when the expected temps will go below freezing, then there's no point giving you any other advice - the mortar will probably crumble and be very weak after it sets.
The only other advice I'd give is to use clean, dry sand, and put it through a filter to remove organic junk and small stones. Washed "brick sand" is what you want. Dry and filtered.
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I don't know why I think what I think, either. It befuddles me sometimes. So, I'm just asking what I need and trying to describe it so that more knowledgeable people can help me out.

As I tried to convey in the post, I will be doing some block, some walkways, and other work. I will use bagged concrete for all concrete work, as well as the footer.

Yes, except where not. (Half pieces for ends, etc.)

Now you ah getting, Grasshoppah! Mortar for the joints, concrete for grouting the cells solid.

As mentioned before, want to fill with concrete, slightly less $$, I think.

For where I live, and the exposure, I want solid concrete fill.

WONDERFUL. SWMBO will not be pleased, but I now have a reason to put it off until spring when she can help, and I can spend the winter finishing my shop. Uninterrupted. TY, TY, TY!

I used to be a form setter. I hated it. But at least I learned that much.

Thanks for your help. I can get mustered this winter, and get it done this spring. I want to set some forms for stairs, etc, and this will be nice to just get it all ready to pour a little at a time. Maybe even call in the big truck and have him make a big pour at the shop while we're spending money.
Steve
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Steve B wrote:

See these for more info:
http://howto.millardlumber.com/blocks/concreteblock.htm
http://faculty.delhi.edu/hultendc/A220-Week2-Lecture-Web.html
http://www.wbdg.org/design/env_wall_masonry.php
I'm not sure what is usually done regarding filling in the cells. I wouldn't think that it's common to fill in all the cells of all the blocks. Some of these diagrams show rebar placed from top to bottom and filled in with concrete - that's probably what I'd do.
I think a lot depends on if your wall is subject to lateral loading (like a free-standing wall) with no right-angle bends in it, or if this is soil retaining wall.
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What I have seen done a lot on 6' high walls is spacing rebar about 4' apart. Screens are put into the proper places within the mortar so that grout does not flow out, and then the isolated vertical row of bricks is poured so that there is a solid vertical with rebar every four feet. The top course may be screened as well to seal the top course.
My wall will take a lot of freeze/thaw cycles, and we have blowing sand that may keep the base wet all winter from the rain and snow. Therefore, I think I'll just make it double strong with rebar and concrete so that I don't have any big cracks. Also, it will be setting on blowsand, and tending to settle, so horizontal rebar, even for a three to six course high decorative pony wall. It's a whole lot easier than trying to straighten or jack up a sagging wall.
Steve
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I've had good luck with both methods. I prefer buying 'mason's mix'. The lime is already there. You add the sand. The advantage of buying the mason's mix is you can go with an extra rich mix for your stucco, later. [BTW-- don't try to mix it in your cement mixer. Use a tub, or a mortar mixer on a 1/2" drill.]

Fine for filling cells. not sure what you mean by 'first coursing'. Don't forget to shove some re-rod in those cells, too.

I make a stucco mix that has 1/2 the sand of my regular mortar mix in the mason's 'portland.

I wouldn't want my mortar to go below freezing for 48 hours. A week would make me happier.
Jim
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On 12/5/2011 5:24 PM, Steve B wrote:

Steve, you have multiple choices for mortar. Traditional is equal parts Portland and lime to 5 parts sand, a bit easier would be to use mortar/masonry cement and sand (the lime is already blended with the Portland) available as type S or type N, or mortar mix which has the Portland, lime, and sand already in the bag. All reinforcing cells both horizontal and vertical should be done with real concrete - sand, Portland, and gravel NOT masonry cement.
You might want to consider another method: dry stack the block, use concrete to create the slushed cells, and use QuickWall for the bond and the finish: http://www.quikrete.com/productlines/QuickwallSurfaceBondingCement.asp
--


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