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Posted: Sat Mar 13, 2010 11:10 am
by NickR
A couple of years ago using Tony's book and this website I did the front garden into hard standing. I was really pleased with the results however...!
Over this winter a couple of things have happened. I built some walls and topped them with Indian Sand Stone. Where the joint between the Sand Stone is the water runs down and the front of the brick has cracked off.
Is there any cure? I was thinking of painting something like the Thompsons’s One Coat Water Seal on the brickwork. I guess the bricks I chose are not high enough quality though the brickie I used said they’d be OK.
The second pronblem is that I built steps in the same way. Brick topped by Sand Stone. The problem is that the mortar between the steps lets water in and the sand stone then lifts and the mortar joints are useless.
The steps are never in the sun so it always damp and cold. Is there a different mortar I should be using? The current one sort of turns (back) into powdary sand.
I've put the pictures to try and explain the problem but happy to provide any more information, any help and advice would be much appreciated.
Nick
Posted: Sat Mar 13, 2010 11:39 am
by lutonlagerlout
firstly,the brickie wants shooting
those bricks are london brick ,claydon red multi
soft as sh**e and i only use them to match existing
he should know and is normally put on the delivery docket for such bricks that they are not suitable for free-standing walls,retaining walls or steps
you could have got a stock type brick or semi engineering brick for the same or less money than those
anyway the nitty gritty is thus,those brick s will only get worse and worse, water seal wont help,render with sbr in it may cover up the worst but within 5-10 years the lot will be blown
sorry for that ,but theres no easy way out
secondly with the Indian stone capping,the biggest problem you have with these is that they aren't designed for capping a wall,a tile creasing and brick on edge or a traditional coping stone have falls and a drip built in,indian stone does not ,so any water runs down the face of the work ,freezes ,expands,then cracks the face of the brick
if you use a mix of 3:1 sand cement with 50/50 water ronafix/sbr on to a surface dust free and primed with neat ronafix/sbr ,they wont come off again
its a crying shame as the brickwork and steps dont look badly built,just those crappy bricks have ruined it for you
LLL
Posted: Sat Mar 13, 2010 1:16 pm
by NickR
Thanks for the response, bad news is never good.
The logic back then was match to the house bricks, doh! If you DIY then you have to take responsibility so I can’t just blame the brickie.
So now I now it’s about managing it until it needs replacing.
Would water seal help to slow it down? I understand it won’t stop the problem.
What rendering would help? sbr is what?
Am I best to replace the wall top sand stone? What’s best?
Am I just not to mortar between the sandstone on the steps or will the mix you suggest be stronger. Last time I used 4:1.
Thanks again for your comments.
Nick
Posted: Sat Mar 13, 2010 2:32 pm
by seanandruby
As LLL says; the render will just delay the inevitable.
SBR= Styrene Butadiene Rubber, a bonding agent for improved strength. For the time being you have a wall steps etc, so you can improve at your leisure.
Posted: Sat Mar 13, 2010 3:24 pm
by lutonlagerlout
a possible get out would be to put capping's with a drip on the wall see here for a rough idea of what i mean
the steps if it was me,I would take all the stone off and build new brickwork in front of the old in a stock brick,then relay the stone to the new slightly larger steps
or as sean says just leave it till the whole lot fails in 10 or so years
cheers LLL
Posted: Sun Mar 14, 2010 6:52 am
by seanandruby
On the subject of brickwork, ( hope you don,t mind me hijacking your post? ) i had to break into a wall the other day and it was a rat trap bond, also known as chinese bond. Good for saving on materials :;):
Posted: Sun Mar 14, 2010 8:57 am
by Mikey_C
sbr is discussed in this thread
Posted: Sun Mar 14, 2010 11:57 am
by Tony McC
seanandruby wrote:rat trap bond, also known as chinese bond
Explain please. This a new term to me.
Posted: Sun Mar 14, 2010 12:00 pm
by carlbeardsmore
I think its when you leave loads of gaps in the brickwork of a wall so it looks like a chess board. It does cut down on the amount of bricks you need... 
Posted: Sun Mar 14, 2010 12:52 pm
by mickg
the bricks are laid on their sides instead of flat with a gap between them of about 2 inches that forms the rat trap, walls were built like this because they use use fewer bricks and are therefore cheaper
using the worlds biggest search engine to find images of "Rat Trap bond"
Posted: Sun Mar 14, 2010 4:51 pm
by seanandruby
Yes that,s it, rat trap. still used here sometimes but is used a lot in india.
Posted: Sun Mar 14, 2010 6:51 pm
by NickR
Back to coping stones...as I always thought a Rat Trap was a song.
How do you join coping stones together? With a mortar joint or butted together? Or a silicone joint?
Nick
Posted: Sun Mar 14, 2010 6:56 pm
by irishpaving
Mortar joint Nick
Posted: Mon Mar 15, 2010 8:40 am
by Tony McC
...but why use "the world's biggest search engine" when there are people here that know and can share the knowledge and so help build-up the repository of know how for which the Brew Cabin is rightly famous?
Posted: Mon Mar 15, 2010 4:36 pm
by lutonlagerlout
another variation of rat trap is a diaphragm wall,its like rat trap,but in block work
I have done a few of these for the big supermarkets,the thinking being that if an artic ,backs into the wall they wont lose the whole wall
basically its like a 2 skin block wall but the leaves are 450mm apart overall, then for every block length ways there is another that crosses the cavity,pain in the backside to build but something different
as a side issue some of the fanciest brickwork i have ever done has been on tescos,mcdonalds and sainsburys,
but when you see the job complete. you realise all that money and time was spent on a bin store or a flower garden for the chavs to throw their wrappers into 
LLL
