Keep concrete, asphalt safe from water intrusion--Best sealers for the job

By Paul Bianchina

It seems like something as tough as your concrete or asphalt  driveway would be able to easily stand up to something as small as a drop of  water. But the effects of rain and snow, especially if that moisture gets into  cracks in the surface and then freezes, can do a surprising amount of damage to  a driveway, walkway, wall, or other concrete, masonry or asphalt surface.

So, before winter hits again this year, fight back by  sealing those porous surfaces against water intrusion. There are a number of  sealers that are formulated specifically for this purpose, and they are easy to  apply without special equipment.

CONCRETE AND MASONRY  SEALERS
For a tough finish on concrete, you'll want to use a  specific concrete sealer. Not intended for brick, block, stone and other  masonry, concrete waterproofing sealers penetrate deep into the surface of the  concrete -- up to one inch of penetration on previously unsealed concrete -- and  forms a very tough barrier against moisture.

Some sealers are formulated for specific applications. If  you have a concrete slab, for example, that is subject to a lot of grease and  oil on a regular basis, selecting a sealer that is specifically made for that  will greatly simplify your cleaning. There are also sealers formulated for  underwater concrete, such as ponds and pools, for sanitary surfaces, and other  applications.

For most masonry surfaces -- brick, stone or ceramic tile --  a masonry sealer is the proper choice. Depending on the type of masonry sealer,  some will also work to seal concrete slabs. Masonry sealers will penetrate into  the pores in the surface of the masonry and seal them against moisture. The  sealer also helps to protect against buildups of dirt, oil, grease and markings  from automobile tires. Masonry sealers are not intended for use on asphalt,  glazed ceramic tile or on wooden surfaces.

Sealers also come in different surface "sheens,"  depending on the look you want. While all of them are clear, some types dry to  a completely flat sheen and leave the surface looking unsealed. Other types dry  to a glossy "wet" look, and the depth of the gloss increases with  each application. There are also semi-gloss sheens that are in between flat and  glossy. The choice of how glossy you want the finished surface is typically one  of personal preference; however, with some types of sealers the glossier the  product is the more abrasion-resistant properties it has.

APPLYING CONCRETE AND  MASONRY SEALERS
As with the application of most coatings, you need to start  with a surface that is clean and dry. That may be as simple as a good sweeping  or blowing off of the surface with a leaf blower, or it may involve pressure  washing or spot scrubbing to clean off heavily soiled areas. If you do end up  having to use water or other liquid cleaners, be sure that the surface is  allowed to dry completely before applying the sealers -- application over a wet  surface will almost guarantee that the sealer will fail.

If efflorescence is visible -- a chalky white coating on the  masonry or concrete that occurs as salts leach out of the cement during drying  -- that needs to be removed as well. You can clean efflorescence with a diluted  mixture of muriatic acid, but most sealers require that the acid then be  neutralized -- a 50/50 mixture of water and ammonia is a common neutralizer.

The sealer can usually be applied using a brush, roller or  spray. Pump-up garden sprayers work well for some types of sealers, as do some  types of paint sprayers. Some sealers are formulated for a single-coat  application, and others require a buildup of multiple coats.

ASPHALT SEALERS
Like concrete and masonry, asphalt is also subject to the  effects of wear and tear as well as the detrimental effect of heat, rainwater  and freeze/thaw cycles. Left alone, the asphalt will begin to deteriorate over  time, and the periodic application of an asphalt sealer will help prevent the  much more expensive alternative of having to remove and replace the asphalt  completely if it begins to break down.

You can apply asphalt sealers yourself if desired. Large  cracks need to be patched first, using a cold-application asphalt mix or an  asphalt crack sealer. After that, the surface needs to be cleaned, and then  allowed to dry if necessary. Depending on the size of the area, the sealer can  then be applied using a special mop, a rough-surface roller, or an asphalt brush.

For this project, you might also want to consider having the  work done by a company that specializes in asphalt sealing. Get two bids from  reputable, licensed, local companies, and remember that the low bid is not  necessarily the best bid. The bids should include patching any large cracks, as  well as a complete cleaning of the asphalt prior to application of the sealer.

Sealers are available at some home centers and hardware  stores, but your best bet for expert advice and a wide selection of products is  to check with a store that specializes in masonry or asphalt products. Each  product will have specific uses, application methods, weather and temperature  application restrictions, and safety precautions, so be sure you carefully read  and follow ALL of the manufacturer's specific recommendations.

Copyright 2007 Inman News