How high can a simgle skin block wall be ?

[michaelthegardener]

Ive been asked to repair a wall that used to have a row of petal blocks on the top he wants it re done with plain blocks but higher than before he wants it to be around 4 foot but im worried this will be to high ? ??? will it ? or is it just to risky to do it not knowing how good the footings are ???

[GB_Groundworks]

cant you dig down at teh back etc and inspect the footing if its 100mm concrete you'll be fine, might be laid on a spread brick if its an old wall or for dwarf walls seen them laid direct on concrete block laid flat.

[lutonlagerlout]

what happened to the petal blocks?
bear in mind these let the wind through whereas noraml blocks wont
the footing needs to be 20% of the walls height
so if its a 1200 high wall you would expect 240mm of concrete
roughly a shovel depth or spit
dont forget that a block alone is not enough,you will need coping stones and these need to be laid with a bond bridge ,I.E> SBR in the mortar and applied to the copings before laying
cheers LLL

[michaelthegardener]

i should have taken a pic i cant dig down as its between 2 drives thats what happened to the petal blocks ! the idiot next door hit it but the rest of the wall is solid as far as i can tell by pulling on it as hard as i can !
thanks for the info on the SBR ill get some

[michaelthegardener]

did this sat afternoon i was assured the footings were good enough and i built it 3 blocks high with copeing forgot me camera though

[mickg]

use the camera on your phone ???

[michaelthegardener]

yeah but its crap quality ??? its a samsung solid :p