Browse Forums Paving & Concreting 1 Aug 10, 2020 8:49 pm Any people good with concrete stuff here? I got some stubborn cement stains when we poured some extra concrete around the house. Some cement stains are on the old concrete slab which sticks out alot. Tried hydrofluoric acid but it didnt really work. I mixed it at 1:5 with water but the stains didnt come off. Ive been told I need to apply the acid undiluted? Also might need to scrub it with wire brush or broom this time. Only had a bristle broom. Thanks for that. I think the mortar has been sitting on these surfaces for approx a year. We’re at handover & they tried to get it off the rubber but have damaged it… 3 1088 Hi everyone, Have just put a shower in the laundry and after only using it 2-3 times have noticed staining on the grout. The tiles were glued onto a concrete wall after… 0 5584 I couldn't attached the photo for some reason. Here is the link to the photo https://pin.it/79jwdMp 1 3261 |