Sealing older concrete

[Colbyt]

I am looking for suggestions on sealing driveway and sidewalks of concrete.

The primary goal is to prevent the growth of mold, mildew and algae as the surfaces in question are mostly in the shade.

Colbyt

[Colbyt]

I am looking for suggestions on sealing driveway and sidewalks of concrete.

The primary goal is to prevent the growth of mold, mildew and algae as the surfaces in question are mostly in the shade.

Colbyt

[raven]

Don't waste your time.

Just wash them from time to time and make sure that they've got good drainage and you'll be fine. Really, sealing on concrete is a waste of effort, turning a fine low/no maintenance syrface into one that has to be periodically resealed.

John

[hallerb]

wonder if thompsons water seal would help, clean thouroughly, use bleach detergent and brush let dry overnite at least.

apply thompsons by dumping on and spread with broom. idea is very heavy coat. it will soak in.

after it absorbs dries water will only bead and easily evaporate it wouldnt be able to soak in and remain wet.

no wet + no mold and such

best part is thompsons is clear doesnt change the surface appearance or texture. reapply every couple years, it wouldnt take much for re applys.

used here it protects concrete from freezing really effective since water cant penetrate the surface

[raven]

From what people have observed here, it does change the appareance, and worse, in the high wear areas, it goes in a very short time, like 6 months or less and then creates a striking difference when the water soaks into the high wear areas but beads on the low wear areas. You end up requiring re-application very frequently if you want to keep an even appearance.

Ideally, you make the concrete strong enough so that it can withstand that sort of weather on it's own. A sealer may help sub-standard concrete, for a little while, but on good concrete, it's a waste IMHO.

John

[hallerb]

Well I am a bit of a expert having treated 2 homes and about 10 friends adopting it too.

NOTE: I said DUMP on spread with broom and let soak in, then reapply a light coat every couple years! After the heavy coat another heavy coat will just lay there it cant be absorbed

If you just sprayt on a light coat it isnt enough

The most you will ever see is a SLIGHT darkening of the treated area as compared to a untreated area.

In a rain treated areas will remain light colored since the water cant soak in.

Commercial construction recognizes the value of treating concrete. Locally every new public buildings concrete gets coated, I was told its a public building code requirement but dont know if thats true.

You cant tell a area has been coated if the entire area has been treated, it all looks the same. If it rains you can see water bead up like on a newly waxed car.

Not all treatments are the same I stick with thompsons.

Its not a paint it absorbs!