Doug Miller wrote:
In article , wrote:
Doug Miller wrote:
In article , "Joseph Meehan"
wrote:
W. Wells wrote:
I have an old house and am repointing some bricks. I would like to
know what the mixture ratio is for cement and sand. I have heard
anywhere from half and half to 3 times sand. I have to have an almost
white color so I can't use the premixed motar. What I have been
mixing ( half and half) seems to fall away when it dries. Thanks for
any help.

How old is that home? Using modern mortar on old brick can cause
damage. You may need a special mix to prevent damage.

Hmmm.... never heard that before. Can you be more specific?

It's important that the mortar not be as hard as the bricks. Old bricks
were not as hard as todays bricks, but the old mortar had much more lime
than todays mortar. If you try to use a new -0high cement mix mortar with
the old softer bricks, the faces of the bricks will start to spall off.

Thanks, John - do you have any idea why that is?

Not a friggin clue, but to make a wild assed guess, I'd say that materials
all move, even something as rigid seeming as a brick wall, and when things
move there's got to be some give: you engineer that give into the mortar
while it's the bricks that give the strength to the wall. If the mortar
is stronger than the bricks, then you're trying to make a concrete wall
with very large aggregate.



John
--
Remove the dead poet to e-mail, tho CC'd posts are unwelcome.
Mean People Suck - It takes two deviations to get cool.
Ask me about joining the NRA.