HERE.
Anyone heard of 'water bond' no
overlap just stacked on top of each other, was taught
this at college for special manhole construction.
Have yet to use it on site though.
We used to use this on manholes back in the 70's. Put simply it's stretcher bond but with another wall of stretcher bond adjacent but all the joints (including the bed joints) are staggered. So if the inner wall is built off the manhole base concrete as normal, the outer wall is started with a split brick to get the bed joints to mis-align. Supposedly this is as waterproof a wall as you can get just by using bricks. Thank God for plastic and concrete manholes.
Â, Feb 21, 2007 #41
gangman
gangman
New Member
VCM
Must admit you've impressed me. Since leaving the classroom I've only met a couple of guys who knew about the perps in english bond, same with water bond, not many know what that is.
In college we were told english bond was the strongest because of the amount of perps that sat on top of one another. My argument was header bond has less than english bond, 10mm x 15mm at each end per course. So that should be stronger.
Sometimes I'll still use water bond on a manhole, never start with splits though, I use half bats, easier with engineering bricks.
One drawback with water bond is putting an arch over a pipe, more little cuts to put in. The way I've got round it in the past, is to use a welsh arch.
VCM if anyone is going to know what a welsh arch is without having to look it up, I'd say you might. If you do I'll be super impressed.
gangman, Feb 22, 2007 #42
Â
Â
New Member
VCM if anyone is going to know what a welsh arch is
without having to look it up, I'd say you might. If
you do I'll be super impressed.
Aha! The good old Welsh arch. This was one of the first things we ever learnt as it avoided the need for a lintel over a small pipe going through the wall. I've a feeling you know what it is but I'll say it anyway.
Say you want a 4" pipe to go through a wall but don't want a lintel. You build up to either side of the pipe but each brick either side is backed off at 45 degrees. A stretcher is then laid over the pipe but this stretcher also has backed off ends at 45 degrees. This stretcher therefore fits perfectly onto the bricks below and keeps courses too.
I'll do a sketch...... be right back
Â, Feb 22, 2007 #43
Â
Â
New Member
In case you're interested
http://s145.photobucket.com/albums/r229/photoman049/welsharch.jpg