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Posted: Wed May 12, 2010 7:57 pm
by ukcleaner
Hi need some help please, I cleaned a driveway with the Karcher T racer and it came up great. I was then told to use sharp sand to replace any lost in the joints. All looked well until as I started to brush it in, it gave the pinkish bricks a yellowish tone to them.
Is this normal, and will it wash away the next time it rains revealing the proper colour I exposed washing them,
thanks for any help or comments!

Posted: Wed May 12, 2010 8:27 pm
by ken
Give the person that advised you to brush in with sharp sand a boot up the arse. Kiln dried sand/ silica sand is what’s used to fill in the joints in block paving. Its about £4 a bag from any builders merchants. Ive never seen dry sharp sand on block paving leaving stains that the rain won’t shift. I have left wet sharp on blocks before that has stained resulting in changing blocks, which isn’t a big problem on a job on progress.

Posted: Wed May 12, 2010 8:33 pm
by ukcleaner
ken wrote:Give the person that advised you to brush in with sharp sand a boot up the arse. Kiln dried sand/ silica sand is what’s used to fill in the joints in block paving. Its about £4 a bag from any builders merchants. Ive never seen dry sharp sand on block paving leaving stains that the rain won’t shift. I have left wet sharp on blocks before that has stained resulting in changing blocks, which isn’t a big problem on a job on progress.
Hi thanks for your quick reply, when I put the sand on the bricks were dry but probably had a bit of moisture between them in the joints. I went back today and spent another 1 1/2 hours brushing entire driveway over, resulting in a few piles of fine sand. Once this was gone you could see much more of the colour of the bricks, but there was still a yellowish "dusty" look to them. I haven't washed the bricks over again, as I was waiting for a nice dose of rain to help. Do you think I am worrying about nothing?
Sorry to sound like a complete amateur but I usually only do crazy paving and this was my first block job.

Posted: Wed May 12, 2010 8:40 pm
by ken
I think you’re over worrying, but next times don’t brush in with sharp sand! Use kiln dried sand

Posted: Wed May 12, 2010 8:44 pm
by ukcleaner
ken wrote:I think you’re over worrying, but next times don’t brush in with sharp sand! Use kiln dried sand
Thanks will do, I think I used too much as well, hence the half a bag I removed from sweeping today!
Cheers again I appreciate it!
Stuart

Posted: Wed May 12, 2010 8:57 pm
by ken
I work on the basis 1, 25kg bag of kiln dried sand will joint 7m2 of standard 200 x 100 x 50mm blocks. And when I clean and re-sand drives it go’s 4 times as far, so 25kg will joint 28m2

Posted: Wed May 12, 2010 9:33 pm
by ukcleaner
Thanks, this was about 15m x 5m and I used about a 25kg bag and a half. The joins weren't too deep but because the sand became damp and is not as fine as kiln, it was a real pain to get into the joins. Today it was easier as the sand had dried to a more fine consistency and as I swept it was more user friendly. What do you think caused the yellowish hazing/dusting on the brick surface?, I'm not a sand expert so any tips would definitely be appreciated.

Posted: Wed May 12, 2010 10:56 pm
by ukcleaner
Just put some of the sand I used under the tap and it turned the water filthy for a few seconds, is this normal and would it sink into the bricks?
Thanks

Posted: Thu May 13, 2010 10:59 pm
by ukcleaner
Spent 3 hours today washing all the sharp sand out and away, what a mess that stuff makes, lucky though it was starting to stain the blocks real bad. I reckon there's 50% sand and 50% dirt in those bags, never again!