Restoring the color to stained concrete

Q.  My patio is large and made of poured concrete that had a green tint added at the processing plant. That was long ago; the color has faded and the concrete surface has a dull, drab look to it. What suggestions can you offer to treat or recoat the surface without creating a slippery surface?

A.  The wisest thing to do is to have a concrete or experienced masonry contractor etch the surface and apply a concrete stain to it.

However, if you decide to tackle the job yourself, the concrete surface can be prepared for the application of a stain by grinding it lightly. Although this is a harder task than etching it with chemicals, it’s a lot safer.

If you choose to etch the concrete, make sure to clean the surface thoroughly, remove any contaminants such as leaf stains, grease or oil, etc. You may need to use a commercial degreaser and/or laundry detergent.

Wet the concrete evenly to prepare for the application of the acid solution and keep it damp, but with no standing water, until you are ready to apply the acid mix. Protect adjacent surfaces.

Try sulfamic acid; it’s a good choice for DIYs because it is much less caustic and dangerous than the other recommended acids – muriatic and phosphoric acids. You should be able to buy it at Home Depot or Lowe’s, or on eBay and some tile stores. But be sure to check the label of the product you are considering to make sure that it is suitable for etching concrete.

If you decide to use muriatic acid – the most commonly used acid by concrete and masonry workers, and easily available in hardware stores – start by mixing one part muriatic acid (extremely caustic!) to nine parts water. Use a plastic pail; never use metal with muriatic acid. Always pour the acid in the water, never the other way around, and do so gently to avoid any splashing.

Gently and very carefully apply the solution to the surface with a plastic sprayer or watering can. If you do not start seeing bubbles, the solution is not strong enough; add more acid to it.

Use a squeegee to spread it evenly. Keep in mind that the floor must remain wet during the entire operation, so if you see a spot drying out, immediately spray water on it with your garden hose.

Watch the floor. When the bubbling stops in about a few to 20 minutes, it’s time for the next step. Some acids do not require neutralizing, so check the label of your chosen acid. If it specifies that you need to neutralize the action of the acid, mix one cup of baking soda in a gallon of hot water and mix it thoroughly ahead of time. Spray the neutralizer on and use the squeegee to spread it evenly.

Now you are ready to rinse the surface with your garden hose. Use the squeegee to push the rinse solution in a corner, and use a wet vac to suck it up. Dispose of the solution according to the instructions on the package. If it is not possible to dump it down the drain, check your local regulations to dispose of it environmentally and legally.

Whichever acid you choose, take maximum precautions, especially for muriatic or phosphoric acid. Cover skin, wear old clothes, eye protection and heavy-duty rubber gloves.

You should be ready to apply the concrete stain of your choice, keeping in mind that concrete stains are a lot better than other coatings for a lasting job, unless you choose epoxy, which is not the best choice for a patio, as it could be slippery.

As you can see, it may be best to leave this job to experienced contractors who will be responsible for the final outcome.

Cats mark territory, leave odor

Q.    I enjoy reading your column every week.

We have a problem with cats marking their territory around our home. We’ve not had this problem until recently. The neighborhood has acquired several mature cats who wander in our yard on a daily basis. We have two altered male cats (indoor only). The influx of “challengers” has created quite a problem.

Our door is an unpainted, but stained, wooden door. It’s the outside cats’ favorite marking spot and the inside cats’ point of retaliation. We have a product (Stink Free*) that works well on the painted surfaces. But, we surmise, the wood is penetrated with odor.

Do you know of product that will clean the wood deeper than the surface? Would sealing the door now–just seal in a smell that will haunt us in humid weather? Could it be as bad as replacing the door! Any suggestions?

*We’ve tried every odor remover available that promises to eliminate urine odor. So far Stink Free is the only one that does the job (at least to our noses!).

P.S. The cats are not feral. Various neighbors have brought in a number of new dogs and cats. We have no idea where these cats live.

A.    If the stain on your door is not too old and still has some sealing properties, you should be able to remove the odor as you would with a painted door. But stains are not as effective at preventing liquid penetration as paint in good condition would be.

Try a different product: Nok-Out. We have used it many times and I have recommended it to a number of people to solve some horrendous odor problems. The worst of which, in our own experience, is when a daughter, who lived in Boston at the time, came home from work to a very smelly bedroom. Skunks had nested under a porch and let loose. Her bedroom window opened onto that porch. She called me and I had Nok-Out express-ship her a gallon of their product. She sprayed it under the porch and saturated the entire bare earth with it, as instructed. It did the job, and she could reintegrate her bedroom.

Nok-Out, to be effective in a case like this, must contact the entire odor-producing source. Therefore, to eliminate the cat odors, instead of spraying it, soak a rag with it (wear rubber gloves) and rub the affected area for quite a while to make sure that Nok-Out penetrates deep into the wood fibers to get to all the urine that may have soaked in. You’ll have to do the same both inside and outside the door since your own cats have retaliated.

Once the odor is completely gone, you should apply more stain on the door to prevent future penetration if the cats continue to desecrate it. And you should restain every two to three years to keep it effective.

You can order Nok-Out directly from the distributor: Osburn Distributors, PO Box 3799, Pflugerville, TX 78691-3799. E-mail: ted@nokout.com. Phone: toll free – 866.551.1927 or local – 512. 607. 6621, Fax: 512. 607. 6324.

Or better yet, you can order it easily from my Web site, www.henridemarne.com. On the right of my blog’s Q&As, there is a yellow coupon with a 10 percent discount code. If you click on it to place your order and mention the code (HDM), the product will be shipped to you and you will receive the discount.

Meanwhile, I suggest you talk to a vet or other cat expert to find out if there are ways to discourage the cats from continuing their assault on your door.

Painting over mold stains

Q.    We had a new home built and after we closed, we noticed spotty areas of mold on the ceiling of our unfinished basement. Either the wood used already had the mold on it or it occurred during the construction process when they closed up the basement without adequately drying it out. The builder was pretty responsive and hired a mold remediation company to clean it up. After they completed their process we were left with “mold stains” on the wood. It is a year later and there is not further growth. Should we paint these areas? We do not want any problems selling the house in the future.

A.    The mold developed because of the high level of moisture exuding from the concrete and other components of the building process. You are fortunate in having had a responsible contractor who took care of the problem. You certainly can paint the basement ceiling to make it more attractive. Prime first with a stain blocker like B-I-N.

Best stain to use on bricks

Q.    I have brick-facing on the front of my house. It is an orange/tan color. I would like to stain it dark brown. Is there a product for staining bricks?

A.    Yes, the bricks can be stained. You will have better success with a solid color, oil-based stain than with a semi-transparent stain. The end result will be as if you had painted the bricks, since solid color stains are really thin paints. Your local paint store will probably handle one or two brands and have some recommendations as to which one to choose.

Stain flaking off of concrete walkway

Q.     Last  summer I had a new concrete driveway installed. Shortly after it was installed, a gentleman that does miscellaneous work around my house decided to stain my walkway with a gray water-base stain in an attempt to match my new driveway.

Over the winter, portions of the stain flaked from the walk and it now looks terrible. This summer I started to power-wash the walk in order to remove the remaining stain. I have not been too successful. Can you advise me of a product that will assist in loosening the stain for power washing?

A.    The success in removing the remaining stain depends largely on how the stain was applied. A stain that flakes off, as yours does, seems to indicate that the surface was not well prepared or that the stain was applied too thick – perhaps with a roller instead of a brush. Or the walkway’s surface is not porous.

You could try one of the environmentally safe citrus strippers available in paint stores. A wire brush may also be needed.

Tough, stain-resistant carpet needed

Q.    I am going to need to replace the wall-to-wall carpeting in my home in the not-too-distant future. I have three dogs who can be hard on the carpeting, and who, once in a while, have accidents which stain the carpet.

With this in mind, I am sure that I am going to have to get a strong, durable, stain-resistant carpet when I replace what I currently have. Can you recommend a type of carpet that would be best able to hold up to the challenge of three dogs?

A.    Your best choice is to call a carpet store and ask for a waterproof carpet or a waterproof pad that has antimicrobial coating and is guaranteed against pet accidents. Mohawk makes such combination; the Smart Strand carpet and the Smart Pad. You should be able to find a Mohawk dealer near you.

Deck is coated with mold, and stain is peeling

Q.    My pressure-treated deck and outdoor stairwells are coated with mold. They are located in an eastern exposure facing open fields. They had been stained about eight years ago and are now peeling too. How should this problem be solved?

A.    Were your deck and stairs coated with a solid color stain containing linseed oil? At this point, I suggest you have all the remaining stain removed. Try pressure-washing to make the job easier, but if this is not completely successful, you may have to use a paint-and-stain remover.

A paint store can advise you as to the best to use for these surfaces — probably a liquid remover, as they are less expensive than the gel or semi-solid types. Once the wood is clean, coat it with a product specially made for pressure-treated wood, such as the Wolman line that penetrates the wood and will not peel.

Removing shiny gloss finish from slate floor

Q.   Over time, the Tech Super Gloss I used on the slates of my kitchen floor has built up. Where I stand near the counter, the build-up is gone and I would like the rest of the floor to look as it once did before the build-up of the gloss.

A. To remove the shiny Tech Super Gloss finish on the slates, the best way is to use the remover offered by the manufacturer of the sealer; in this case I believe the product you used is from Home Depot. They should have the appropriate remover. Or a tile store can offer you a choice of several removers that you should try first in inconspicuous places before doing the entire floor.

You should apply a sealer to the slates and joints to prevent the penetration of stains from anything dropped on the floor. The best type to use is a penetrating sealer that will protect without giving you a shiny gloss finish.