Hello,
we recently laid a slate patio. After the builders applied the jointing compound (Gftk Vdw 850-plus), the slabs developed a horrible white hue. When they are wet you don't notice it, as soon as they dry, it's horrible. Nothing compared to what they were dry before the grout was applied. It kind of looks like efflorescence but it's not removed with brushing. I am not sure if the grout is responsible for this, it would be a coincidence if not, but I don't know.
The slate supplier recommended to use Lithofin Builders Clean, which I just did, but it doesn't seem to make much of a difference. I used it 1:10 diluted with water, maybe it's too diluted?
Any other product/method you can recommend? Would highly appreciate it! Thanks
Please find attached some photos.
we recently laid a slate patio. After the builders applied the jointing compound (Gftk Vdw 850-plus), the slabs developed a horrible white hue. When they are wet you don't notice it, as soon as they dry, it's horrible. Nothing compared to what they were dry before the grout was applied. It kind of looks like efflorescence but it's not removed with brushing. I am not sure if the grout is responsible for this, it would be a coincidence if not, but I don't know.
The slate supplier recommended to use Lithofin Builders Clean, which I just did, but it doesn't seem to make much of a difference. I used it 1:10 diluted with water, maybe it's too diluted?
Any other product/method you can recommend? Would highly appreciate it! Thanks
Please find attached some photos.
