Repairing Damaged Concrete
Learn how to repair damaged, crakced and scaling concrete.
It will pay in the long run to have your cement work done by a craftsman who really understand cement. If it is done incorrectly, it takes a lot of effort to try to restore and in spite of your work it will never be what it should have been. Some common surface flaws of cement is caused by mixing incorrectly. The concrete forms a dust like substance on the surface that can be rubbed off. The concrete will need to be swept or brushed carefully and a concrete sealer will need to be applied according to package directions. If the case of ¡§dusting¡¨ is serious, the surface will need to be coated with a commercial surface hardener and then sealed.
Another unsightly problem is scaling; in this case the surface mortar peels off. The treatment for this is: 1:1 ratio of linseed oil and turpentine, place two coats on surface. Make sure the area is dry before walking on it. This treatment will need to be repeated for a few years in the late fall.
The small fragments of cement that break away are called popouts; these are small holes. Clean all debris out of the holes and patch with patching compound.
Preparing your own patching mortar
1. Mix one part Portland cement with three parts sand
2. Use enough water to form a stiff paste-like substance
On the other hand, you may purchase a commercial standard patching mortar with complete mixing directions on the package.
Cracks in concrete* Clean all dirt and debris from cracks before starting the patching process.
* Under cut the sides of the crack to provide a good attachment area for the patch. With a hammer and chisel chip loose concrete away.
* Then holding chisel at an angle undercut the crack so that it is wider at base than at surface.
* Using shop vacuums remove debris.
* A 1:1 ratio of cement sand grout mixed with water to the thickness of paint should be used to coat the damaged area this will improve the bond. You can also purchase a commercial bonding agent.
* Dampen crack and coat with a bonding agent while still wet.
* With a trowel press material into crack and smooth it out.
* When patch is dry brush, it down to matches the adjacent surface. Keep moist to cure for at least one week.
Masonry crack filler can be used to fill narrow cracks. These are found in cartridges to be used in a caulking gun.
Latex and epoxy patching compounds are more costly than patching mortars, however the bonds they form is stronger and do not require a bonding agent and are self curing. (Mortars) must be moistened for approximately a week after patching.