by greedypebbles »
Wed Sep 01, 2010 2:51 pm
If the surface is falling away then it is past its useful life; it depends really on how old it is but in reality under normal foot traffic this shouldnt happen unless the material used was not correct for the application, probably mixed too weak (ie not enough cement) to save money. Water has got into the concrete and then frozen, expanding and cracking the structure. A good strong concrete would survive this.
As even more bad news, if the surface has gone then water ingress this winter will be worse and the amount of damage will be greater and steadily get greater as time goes by.
What is falling away is already broken and cracked beneath the surface, to repair it would involve something soaking into the material and strengthening what you cant see. This is not going to be something which can realisticlly be done. ANy suggestions or thoughts you may have about pouring a new surface over the top will fail because you are ultimately laying on top of a failing structure, the new surface will just crack and fall away.
The only thing you can do is try and stop it getting too much worse. A water seal will stop further moisture getting in, you can by water sealants from any DIY shop, but I repeat this will not immediately stop the existing damage falling away when you brush it and you may find yourself having to reapply the sealer next year.
SO that would be my advice, apply a water sealant, dont expect miracles and then reapply on a dry day every six months or so until eventually you'll have just a sound surface left - it just won't be very attractive. A more realistic proposition (and to be honest what I would do) is just live with it for a while then replace the whole thing.
Someone else may have some more positive advice or identify some wonder chemical, however without strong evidence I would take it with a pinch of salt in your position.
