How do you paint over a cement driveway that has already been painted and the paint is flaking off.?

Will the new paint lift off if the old paint is still flaking. Could you seal the old paint? Or does that just seal the paint and does not adhear it to the drivewayHow do you paint over a cement driveway that has already been painted and the paint is flaking off.?
Understand what is going on. Paint strippers are high in alkalines(not acids). Lime is an alkaline. It is used in cement. With the rains and the washing of the driveway, a micro amount of the lime dissolves to the surface. If there is paint in the way, it is lifted off as well. Easily.


Paint is a coating. It is not a glue(mind you in some cases you would swear otherwise)


Sticking it to cement is difficult even when done right with all the pre-steps done.


This is how it goes: first cement is dry-swept off clean. The next step is to mop the cement with a solution of Muriatic acid (a form of Hydrochloric acid)into water. Muriatic acid will not touch the paint as you can buy the acid in ';plastic bottles';. So if it does not eat through the plastic bottle, how different is plastic paint?(Latex-100% acrylic) Make sure it is 100%. It costs more but you get what you pay for.


The cement will fizz as the surface lime is neutralized. Ph value gets closer to 7 (plain tap water) which will not affect the paint.


Then wash off cement with water hose to get the acid off. You can scrub the surface to to remove more loose paint. Let dry.(at least to a damp dry) Read directions on the paint can.


Use latex cement paint. It holds better than the oil based floor enamels and is more impervious to the lime and seals the driveway up better with a coat of rubberry-plastic (basically what latex is).





Paint in all situations stick to surfaces that stick(or not). It will paint a pebble just as well as the solid concrete under the driveway(but you can broom a pebble away.


So to; with flaking paint.(pebble like)


So you ';powerwash the driveway'; and get off the majority of the flaking paint, followed by sweeping it wilth a stiff broom(to get off more loose surface-and maybe a putty knife in the back pocket to lift off paint you see that is separated but sneaks under the broom. Loose is loose.





Now, if you never did the muriatic acid wash prior to the first coat, you can still do it to the now exposed concrete ';as these areas are extra high in lime';. Use a soft haired paint brush, because you are dealing with acid(and yes it burns if it gets on you and wear protective eyewear and don't do it in an enclosed area).


No use painting acid on top of the paint that stuck because it won't go thru the paint to neutralize the lime underneath, so it is just wasted. That is, in areas that is just solid paint. You can overlap in the bare areas(onto the paint) as there may be microcracks in the paint that the acid can possibly reach exposed concrete.


Give it about 15 minutes/ half/hour and then go with the water hose and hose down the driveway to wash off most of the acid.(and broom off more loose paint).





Let dry(or just be dampish) If you can't paint the same day, fine. Next day, if that is the situation, lightly spray the driveway to make it moist(no puddles of water) before painting.


Find driveway paint(waterbased stuff)


Driveway sealer paint(it is just glorified black latex paint) requires this procedure be done as well as any other cement paint.


I have used oil based cement paint to do basement floors - procedure is still the same.


Put no other product on the cement(primers are just paint so that just complicates matters) Read what the finishing product wants you to use. and follow it to the letter.


Actually a cloudy cool day(non raining) is best for doing the driveway(so it does not dry too fast).





As for painting through the already dry paint to make it stick underneath. That will never happen. What is stuck, is stuck. That is no different than applying glue to the surface of wallpaper and hoping it soaks through to the backside to stick to the wall. Not gonna happen(especially on plastic coated wallpaper)


Paint is not impenetrable(moisture does get through going down or up from the ground under the driveway(from the subsurface water table)- but molecule by molecule.





This task will happen again down the road if your driveway is exposed to the elements(rain, snow) as all the cement has lime in it.





It is the properties of cement.How do you paint over a cement driveway that has already been painted and the paint is flaking off.?
Pressure wash the driveway first. The old paint will continue to peal away taking the new paint with it. You need to get a good adhesion or just keep pealing.





The other thing you can do is to scrub the driveway down with a Muratec acid solution. This will remove the pealing paint as well as most anything else on your driveway. Make sure you follow directions and wear proper chemical resistant gloves and eye protection. rinse and let dry thoroughly before you try to repaint.
If you paint over flaking paint, then you do not get good paint adhesion to the surface you are painting. Therefore, your new paint job will flake just like the old paint job.





You need to remove all of the flaking paint and then prime the surface in order to prepare it to accept the new paint. Either borrow or rent a high power pressure washer. This will certainly lift and wash away any old paint that is not securely attached to the driveway.





Use a good cement primer. Ask your local paint store or a swimming pool company for the correct primer and paint to use on cement. With all due respect to home improvement store employees, they are not always trained to recommend the right product, I have learned.





With painting anything, the prep work dictates the success of the job along with using the correct products for the job. It is the same amount of labor to use bad paint as it is to use good paint, so do it right from the start. Allow your driveway to completely dry and paint on a clear day and, if possible, try to avoid painting in direct sunlight. Good luck to you.