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Hi Everyone,
I need expert advice and also suggestion that how much variation is accepted or tolerated in Block size.
As per my understanding, we are seeing the routine variation up to 5-8 mm in Blocks size.
What are the repercussions if the varied size blocks are used in block masonry? What if the variation problem persists due to supply market incapability , what can be the workable solutions in terms of masonry or applications?
Will appreciate your response on the same with examples or suggestions
 

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Not a masonry expert by any means but I know that it's a pretty exacting profession. 8 mm is more than a 1/3rd of an inch which is quite a bit and I think it would challenge the ability to keep the courses level with the required amount of mortar not getting out of control.
What do the masons laying the block have to say about the situation?
 

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What do the masons laying the block have to say about the situation?
We say more or less mortar. Masons do not measure in millimeters

The only time anybody cares about joint sizes is on jobs where mortar joints are critical. Rarely are mortar joints actually measured unless there is a huge discrepancy

As we always say, if you have a concrete saw you have bond.


David
 

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Is this for the 7 story building that was referenced in the other post? The reason I ask is that I would think the larger and taller the structure is the more critical it might become.
 

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I can recall a block manufacturer 30 years ago around here. They produced a lightweight block which would not be true on the vertical plane.
One side, at the bottom of the block, could be plumb and flush with the previously laid course, or the inside of the wall.
The other side of the bottom of the block, the outside of the wall, would not be flush with the previously laid course. Bumpy.
I suppose, thinking back, that the blocks were either produced or manufactured a little crooked. Or the blocks settled crookedly after casting and while drying out. Who knows. They are no longer in business. They sold out to a larger company, who closed the plant.
 

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They don't meet spec for use in the USA, the tolerances on CMUs are much tighter then brick units....

Send them back, if you have another source with in trucking distance..... they'll slow down a good mason, and befuddle a boot. the mortar joints should never exceed 19mm total , 2-3 mm minimum with fine mortar.....

Over 3/4"-19mm the bed joints will produce a much reduced strength wall as confinement of the mortar goes toward Zero.

Such poorly made block aren't very likely to meet any of the other specs of CMUs used for load bearing walls or exposed to any winds.....

Here, your building wouldn't be considered for ANY conforming Mortgage or loan, nor would it pass any building inspection.

Few underwriters would offer insurance for the end users.... If the builder used this crap, what else is cut rate??????

Would you sell insurance to 40 year old sea front low bid 12 story Condos in Miami Florida?

If the blocks pass ALL other specs, cut the long one to within 1-2mm of the shortest unit in height.

For a large building it would be cheaper to BUY the CMU plant, fix the dies/ labor errors, produce to spec untis then resell the plant.

Make sure parts are availiable for the block making machine....
 
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