Are there different grade of blocks? Is there a standard size/thickness/density? For example if you were building a stem wall to support a one or two story structure would you use a different grade/size/thickness? What about if the home were all block? Does this question make sense?
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Replies
Yes I understand your question, but it's really general so let me try to give you some answers.. the size of the block has more to do with it's strength than anything else. in addition the weakest part of concrete block is the morter joint.. concrete block isn't terribly strong, I've seen concrete block walls blown down in high straight line winds..
To me the solution lies with ICF's (insulated concrete forms) that's those foam blocks or panels that you put in place and then pour concrete into them. If you are at all able to figure out how to put building blocks to gether (you now the kind you got as a kid?) then you can build with ICF's.
It takes about as much strength to do that as to lift a feather pillow and winds up being dramatically stronger to boot!
Plus you have a well insulated house that is easy and cheap to heat and cool..
Parge the outside with stucco and the inside you can finish pretty much the same way as a regular house (or parge it too) The only advise is to run all the wiring and plumbing in place before you pump the concrete in..
concrete block or poured walls without steel is worthless. A concrete foundation without steel is just a little better than a block one with. I refuse to NOT put steel in either. Steel is chep! It's the labor.
you were building a stem wall to support a one or two story structure would you use a different grade/size/thickness?
That's some structural engineering-type questions. Some places would use an 8" wide block for a foundation wall, and a 6" wide for the above-grade wall. Others might use a 12" wide foundation block. Might be that a wider block is used to give a brick ledge for veneer face, brick, too.
There are lightweight block and there's structural block, and there's CMU, too--so I can see how it makes for complicated choices.
There are 4,6,8,10,12" wide block for different applications. All (generally) are the same 8"x16" face dimension. Again, generally speaking, the width determines strength and therefore use. Rebar reinforcing determines structural performance further.
Yes, one could build all structural walls of a house out of concrete block ("CMU" is the same thing - "concrete masonry unit").
my house is all block and it survide a direct hit from hurricane Ivan with no damage, but then I also filled the cells with concrete too.
Well, I read at one ridiculous answer above... Everybody gets their opinion though...
Standard block sizes used in residential construction:
4" = 4"x8"x16 nominal size. - normally used in combination with brick for a veneer wall
6" = 6x8x16 nominal - less commonly used
8" = 8x8x16 nominal
12" = 12x8x16 nominal used for higher walls, basements, etc.
I said the nominal size of a 4" block is 4"x8"x16. Actual size is 3 5/8 x 7 5/8 x 15 5/8. The missing 3/8" is for the mortar joint so the finished size is 4"x8"x16
4" block comes in solids and regular... Solids are used for cap block, etc.
8" comes in light weight (LW) and 75% solid. The 75% solids can be used in lieu of filled bocks for caps, etc.
12" comes in LW and 75% solids. Buy the 15% solids and your bricklayers will hate you. :-)
Re your stem wall application, you have to answer 2 questions:
1) What is the approximate height of the stem wall?
2) Will the house be a crawl space or a stem wall/slab on grade foundation? - Ie: will the stem wall support a slab?
Either way, generally speaking, the foundation wall will be the same thickness for a 1 or 2 story building. Also realize that all my answers are what is commonly done here in NC.
Re your Q: >>What about if the home were all block<<, if it were a one story house it would probably be 8" block filled with "grout", and perhaps verticle rebar - especially in florida. A 2 story block house might be filed 12s for the first story and filled 8's for the second story.
Re sizing of block, you gotta understand that block and brick work off of 4" and 8" modules. That's why you don't normally see a house foundation that is 40'3" long - for example... It's either gonna be 40' or 40'4" or 40'8". Modular and oversized brick has a nominal size of 8" long and 4" thick. The height is 3 courses of modular brick = 8" (an 8" block) and the height of oversized brick is 5 courses = 16" or 2 courses of block. This way the brick and block all "stack up" nicely.
Edited 4/5/2005 6:39 pm ET by DIRISHINME