>>”Would it be as simple as sticking re-bar and pouring concrete in the cavities?”
Seems to me that what you just described is called a “pilaster” — but the rebar normally (I think) goes down into the footer, where it’s wired to rebar there.
But it might be a substantial help to do it even without the connection to the footer. (“Do it” = add pilasters every three or four feet.)
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Replies
short answer, yes it will improve things and the cement block will become more sturdy..
Poured cores can help, but not called pilasters.
A pilaster is where a wall has a bump out to thicker for re-inforcing. Examples in this case might be:
If he had a wall that was 8" blocks and every 10' there was a verticle stack of 12" lifts
or
if he had a 'pier' of 8" blocks acting like a post added to the side of the long wall every so often.
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I stand corrected -- my use of the term was based on volunteer work I did with a block crew and the architect that thought he knew what he was doing. (The masons knew WAY more.)
Politics is the antithesis of problem solving.
Well, the purpose of a pilaster is to stiffen/brace a wall, so if you core pour every four feet, that core with rebar would do the job of a pilaster in some degree.But for an archy to use the term that way...maybe he was fresh out of archy school
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
>>"But for an archy to use the term that way...maybe he was fresh out of archy school"No, not that one anyway. The project was building a stone-wall sign in front of a church. And it was the Eagle Scout project of a kid who knew me. He had done a lot of good planning, and had rounded up the folks to get the job done.And for design, he had 'rounded up' one of the members of the church who was a retired architect. I think the guy was about 85 years old when the project was done (1990?).For block and stone work, he got a local family that had been in the masonry business for decades.I was just one of the "strong-back, weak-mind" laborers.And it was quite entertaining to listen to the masons as they critiqued the archy -- they described a number of elements of the sign that were overkill. Including his demand for numerous rebar-filled core pours, which he had called pilasters.
Politics is the antithesis of problem solving.
There are two ways top re-inforce a block wall. One is with aldder ties - wire that is laid into the mortar joint horizontally as the block is laid. This provides good lateral tie against something like the force of earth pushing against one side of it for a foundation.
The other is to place rebar vertically and pour the cores full ( grout them) with concrete. As mentioned, this works best when the rebar is tied to the steel in the footing, but can still help you with your situation. The greatest force acting on your wall ( since it sounds like the soils are stable after 30 years of testing) is wind on the top fence portion. This stress can try to peel off the blocks on top that the fence mounts to.
I am not sure how you plan to mount that fence, but there are various hrdware solutions. Most I would consider would be a post bracket of one kind or another from Simpson, set into concrete in those cores and with rebar in the same core.
That way, you are tying not only to the top block, but to the whole column of blocks under it sharing the same core. It will handle more lateral force from wind that way
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Short answer,yes it would help to sturdy the wall. You probably just need a mortar or concrete mix . Rebar probably would be overkill.
mike
Yes, it is that simple, and what you describe is done all the time, but like others have said the rebar is usually made fast to the footing. In your case you won't be able to, but tieing the blocks together will significantly strengthen the wall.
Typically the reinforcement is done about every four feet along the wall.
Here's some correction of the terms, though.
The material in the joints between the blocks, holding them together, is mortar.
The material you would fill the block cavities with is called grout. It is not the same as the material used to fill the joints between ceramic tile, but the same word is used for both. The grout for filling block cavities differs from typical concrete in that it has a smaller aggregate (often pea gravel so it won't get hung up) and is prepared to a looser consistency.
A pilaster is a column formed as part of a wall. It can be an actual pilaster, formed by using a different size block as someone described, in which case it adds strength, or it can be a decorative pilaster, such as made out of wood in the interior of a historic building, in which case it is usually just attached to the wall.
If you plan to fill the block cavities with concrete consider the addition of forming and casting an integral concrete cap(4-6" thick x 12" wide with rebar connected to vertical block cavity rebar) to tie the blocks together. This would also provide for a more substantial substrate for anchoring the fence assembly.
If the block wall is backfilled on one sire, consider adding pvc weep pipes before pouring the concrete into the cavities.
FWIW..............Iron Helix
We probably could stand a bit more info, even for all the answers you've already gotten.
Your location, for one. Answers for CA are different than for CT, ditto AK and AL (or even AR).
Also, is this a property-line situation, as is so sommon in the far SW, NM, AZ, SoCal?
Attached to any buildings?
How is the present fence attached to the wall? Metal posts down into the cores? Wooden posts into cores?
Are the present CMU capped? If so, how?
Is the present wall a retaining wall in any sort of way? This is very cruical.
Presuming you can see into the cores of the blocks, how deeply?
Filling thirty 5"x5"x 48" deep core holes (20' = 240" 240/16 = 15 blocks, 2 core holes per block = 30) sounds like a very, very long day. My calcuator makes 5x5x48 to be 1200ci, or about 0.69cf * 30 is 20.8cf, or just about a cubic yard of n.s. grout. Uhm, quick peek says Qwikcrete NSG is 0.58cf per bag, is 38 sacks of grout, which makes my back sore just typing it.
So, you may see why the questions can be needed to help us help you.
Any chance of even a celphone photo of this?
sure...
muddy the waters...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
"Some days it's just not worth chewing through the restraints"
muddy the waters
You said "mud" <g>
OP might need a long ton of it.Occupational hazard of my occupation not being around (sorry Bubba)
you trying to get him to use mortar now????
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
"Some days it's just not worth chewing through the restraints"
I have a 4'x20' hollow cinder block wall
Is it cinder block or concrete block? Cinder block is usually solid.
Edited 7/4/2009 7:39 am ET by woodturner9
Each block have 2 hollow openings running through it so I guess they're concrete blocks.
....."Cinder block is usually solid."....
That is not true. Cinder blocks are made with the same type of pattern as concrete blocks. The use of the term is a hold over from the days they were common. They fell out of use when people realized that the cinders they were made with are corrosive, to this day I will slip up and call a concrete block a cinder block, just information.
"If all else fails, read the directions"
Cinder blocks are made with the same type of pattern as concrete blocks.
Not in the midwest and west. A cinder block, also known as a "slump block" is a solid block and is not made from concrete.
The term "cinder block" seems to be used imprecisely in much of the country, though, to refer to concrete block such as you describe.
Looks like I get to learn something new, never heard the term "slump block" in the north east, have a good one.
"If all else fails, read the directions"
"Concrete blocks" are made with concrete. "Cinder blocks" are made using fly ash and industrial slags as well as the cement. Manufactured that way because they are lighter and easier to work with.
In some areas they are also called "light weight blocks" although that term includes blocks made of any materials or incorporating aerated concrete.
Shapes are the same as far as I know , though you can order "solids"
Edited 7/5/2009 11:13 am by dovetail97128
Exactly.
"Cinder blocks" are made using fly ash and industrial slags as well as the cement. Manufactured that way because they are lighter and easier to work with.In some areas they are also called "light weight blocks" although that term includes blocks made of any materials or incorporating aerated concrete.
As I said in an earlier post, the term is used imprecisely to include a range of products. Engineers use the terms "light weight concrete block" or LWCB or LWCMU (light weight concrete masonry unit) for the blocks you described.
Both cinder block and slump block are vernacular terms, and it's becoming apparent there is a range of variation in the use of those terms.
Thanks YesMaam.