keeping mortar damp

[J Burns]

A few weeks ago I used mortar to patch spots on my front steps. In the next three days I misted it several times with a pump-up sprayer, but the surface would dry between sprayings.

I have two chimneys of brick covered with cement (mortar, I presume) and painted white. Some of the cement has come off. I'd like to patch it. I'd also like to patch cracks in the cement slabs that keep rain out of the chimneys.

What's a good way to keep mortar damp? Wet cloths and plastic? Is summer in the South a good time? Hotter bricks would mean faster evaporation but might speed curing.

Is cooler, damper weather preferred? How long must fresh mortar be protected from rain?

Do I need to clean out the cracks in the chimney caps for the mortar to adhere? Is an additive recommended?

[Joe]

Mortar over non porous brick will cure OK covered with plastic, although it is often uncovered briefly and wetted down to ensure thorough cure. After a 24 hour cure most mortar will OK in the rain. Your bricks must be rather porous if there are dry out problems. If similar brick was used in the chimney, it might be smart to have experienced masons deal with the reconstruction. Putting on a new chimney cap or lifting one for repairs requires a strong back and sturdy scaffolding. The pros will also be able to deal with the type of brick you have with respect to porosity problems.

Joe

[Frank]

A chimney guy resurfaced mine with a composition type material. Looked like a thick paint or thin mortar. Don't think he preped surface. Think you can buy and DIY.

[jamesgangnc]

We've got that on top of ours as well. Does seem to work. We have issues with our chimney absorbing water and then dripping inside. It's rather big and exposed on 3 sides. About every 5 years I spray a "sealer" on the outside and that takes care of it for another 5 years.

I just hit new concrete with a light spray from the hose a few times during the first day. After concrete sets up it's pretty hard to disturb with just a water spray.

You might try soaking down the chimney real good before you start fixing it. If the surrounding area is wetted down well it doesn't "rob" water from the new concrete as much.

I found a product called super por-roc that is for setting posts and thing in concrete. It can also be used for repairs and gap filling. Gets hard as hell. A little pricy but not bad for small repairs.