How many cement blocks

[1930]

I know there's online calculators but they confuse me.
Plus I'm out in the middle of the woods and the Sun is overhead and I can barely see the screen of this phone.
Can anyone here tell me how many standard cinder blocks it would require to build a 30 by 40 building with 8 ft walls?

 

[1930]

I'm not looking for dednutz accuracy I understand that you have to account for Windows and Doors I'm just looking for a rough estimate

 

[CausticUrbanCoast]

Online calculator says 270 and 360 per wall? So 1260.

That's for a 16"x8" block I guess. Concrete Block Calculator & Estimator - CEMEX USA - CEMEX

 

[/pine]

A standard CMU (regular block) is .8 square feet...
total SF 30x8 =240 x 2 = 480

40x8 = 320 x 2 = 640 + 480 = 800 / .8 = 1000 blocks

did this in my head no guarantees...

 

[orezok]

A standard CMU (regular block) is .8 square feet...
total SF 30x8 =240 x 2 = 480

40x8 = 320 x 2 = 640 + 480 = 800 / .8 = 1000 blocks

did this in my head no guarantees...

Actually an 8x8x16 is .89, BUT since at the corners when using running bond you gain a half block every course (end of block). Your .8 is probably reasonably close.

 

[KennyG]

Actually an 8x8x16 is .89, BUT since at the corners when using running bond you gain a half block every course (end of block). Your .8 is probably reasonably close.

Actually, it would go the other way and make the effective area larger. But that would depend on the size of the building. I would just calculate the number of blocks in each dimension and then multiply those. 12 blocks high, 22 blocks wide, 30 blocks long. 2 x (22+30) x 12 = 1248 blocks less the doors and windows.

 

[/pine]

Actually an 8x8x16 is .89, BUT since at the corners when using running bond you gain a half block every course (end of block). Your .8 is probably reasonably close.

Technically...a standard CMU (regular block)...actually measures 15 5/8" X 7 5/8"...allowing for a 3/8" mortar joint at the bottom and one end...so...

15.625 X 7.625 =119.14 / 144 = .823 SF/CMU (actual)....

Obviously you add for breakage and subtract for openings...

Another factor is if the lintel/ tie beam is formed and poured in place the top course of block is not needed...otherwise the top course will not be standard blocks but "knock-out" blocks that allow the webbing to be removed for the concrete tie beam...precast units would be required over any window or door openings...

 

[orezok]

Technically...a standard CMU (regular block)...actually measures 15 5/8" X 7 5/8"...allowing for a 3/8" mortar joint at the bottom and one end...so...

15.625 X 7.625 =119.14 / 144 = .823 SF/CMU (actual)....

Obviously you add for breakage and subtract for openings...

Another factor is if the lintel/ tie beam is formed and poured in place the top course of block is not needed...otherwise the top course will not be standard blocks but "knock-out" blocks that allow the webbing to be removed for the concrete tie beam...precast units would be required over any window or door openings...

True, but when you add the joints they are 8x8x16 therefore .89 actual for count. Unless of course you install them without mortar.

 

[1930]

Thank-you for the replies

 

[Leejohn]

I don't want to be a smart a#s but did you have math in school??