Browse Forums Paving & Concreting 1 Jul 01, 2010 10:05 pm We had two 4m*3.5m slabs done last week. The soil was heightened with 200 mm deco and watered in to compact the deco, just before putting the forms on. The slabs are 100mm (200 beams), F62 reo, and have plastic underneath. One slab looks good, but the other has started to 'blister' (see photo). Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ When hose wetting the concrete the top layer comes off at one end of the slab. If you rub it off, it appears that there is some loose sand under the crust. It is only millimeters and then there is solid concrete, but I hate loose layers before painting.... and it just doesn't look good. The part where the top peels is where the concrete of the second truck was used. The weather was dry, just overcast and about 20C. I called the company and they say the blistering just happens sometimes, I shouldn't worry and just remove it with a hard broom. I never concreted myself, but from reading through the threads here it appears to me that they have started to work the concrete before the bleeding of the concrete from the second truck stopped. I would like to know the reason so I can pay attention with the next slabs. I might want to try it myself next time. We want to paint the floors before installing the sheds. I read we need to wait 28 days before painting and that pre-treatment is critical. I think I will need to pressure wash the 'blistering' slab and try to blast off the top layer first, then acid etch. Would it be ok to acid etch after 2 weeks, then erect the sheds and do the painting when at 4 weeks after pour? Then we can etch without the sheds on. Would paint fill the unevenness from 'blistering' or should we we repair the slab first, and if so, how? As we want to keep tack (leather) and hay in the sheds and prevent rising damp, is it advisable to seal the concrete before painting or does paint do this enough. I am getting confused with all the different paints, sealers, acrylics, polyurethane and 2 pack epoxy. Too many choices.. Any advice very welcome. Re: New 'blistering' slab... why and how to paint 2Aug 10, 2010 10:30 pm Bleed water happens after the job is placed... To me it look as though they use the broom waaaay to early in the process. PM me if you want to, I might have a cue or 2 to share. Where you are coming from is where you are going to... That sucks! Hope it all works out. Good to move away from steel anyway for all your reasons, but it's also thermally poor. 16 18168 Hi All, I just wanted to close this topic out with an update. So we ended up agreeing to a number with the insurance company, and after an extensive amount of hand… 8 24153 A Sabco spin mop, minimal moisture, not very regularly. I was told these hybrids are water resistant 🤷♀️ 2 9309 |