Refinishing an old softwood floor

Q.  I have an old farmhouse that I’m slowly redoing. After removing 3 layers of Lauan and Formica on the kitchen floor, I found a softwood floor set interestingly diagonally to the walls. I would like to sand and finish this floor.

Softwood flooring
Unfinished wide-board flooring

I would use polyurethane on it if it was a hardwood but I’m afraid if I finish it that way and something is dropped on it, (silverware etc.) It would chip the polyurethane and eventually look bad. Do you know of a better finish I could use?  Would a boat-building epoxy be a good choice or would it crack between the floorboards? Is there an epoxy made that is non-yellowing?

A.    Formica on the kitchen floor? That’s a new one on me.

You may be down to the subfloor. Before the advent of plywood and particle board, all sheathing on floors and walls was installed diagonally to prevent them from wracking.

If the subflooring is in good enough shape to be used as the finish floor, go ahead and use polyurethane. It’s OK on soft wood. I used it on my pine floors nearly 30 years ago. An experienced paint store person can tell you which varnish they recommend that would not yellow.

The traffic areas will have to be re-coated every few years, but that also goes for hardwood floors. Softwood floors are more prone to denting from furniture, etc., but that’s part of their charm. And I don’t think any finish would prevent denting.

Refinishing a floor with Milsek

I always appreciate hearing from readers about their experiences with various products. The following is from a reader in Vermont:

“Some years ago I was introduced to Milsek from your column. It has done all that I expected and friends have been wowed also. In respect of a query to you regarding “cleaning wood floors,” I thought you might like to be told of my recent discovery. I have hardwood floors, the dining room and entrance hall were beginning to look very spotty and grimy after 30 years of wear. No help from professional other than a suggestion to re-sand.

“Downheartedly I suddenly thought of Milsek, with a ‘what can I lose’ attitude. Using a barely damp cloth I cleaned and polished dry as I went along. The result was fantastic, the spots are gone, many scratches also and the shine is beautiful without any slippage at all. Hard work, yes, but certainly worth it. Thank you for putting me onto that product.”

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.

Insulating a cantilevered floor

Q.    I have a two-story colonial. The second floor extends two feet over the first floor on the front side of the house. The problem is heat loss. The section of floor  on the upper level that overhangs is often cold, especially when the wind blows.

What is the proper way to insulate this overhang? Currently the underside of the overhang has non-perforated aluminum. I believe fiberglass insulation is packed in between the floor joists and the insulation sits directly on top of  the aluminum. What would you recommend to improve this?

A.    Since the condition is worse when the wind blows, it tells me that the non-perforated aluminum is not tight, and the wind penetrates around its perimeter. One possibility is that  the entire depth of the projecting joists may not be filled with fiberglass insulation. Another possibility is that the band joist may not be fully insulated.

Since fiberglass is a porous filter that works in slowing down heat loss only when tightly enclosed, the wind robs it of that property and cold air circulates through it. The easiest solution is to remove the aluminum soffit, make sure that the entire joist depth is filled with fiberglass insulation (if not, add some or replace the existing insulation with the correct size) and install plywood, properly sealed, around all edges.

If there is enough room between the bottom of the joists and trim board at the base of the wall, add rigid insulation–as thick as will fit–fastened to the bottom of the joists. Then caulk the perimeter and cover it with the plywood.

Stripping wax from floor tiles

Q.    My son and daughter-in-law bought an l8-year-old house in Florida. The floors are covered in Mexican tile. The original owner used a wax on them all these years and they are dark brown, instead of the reddish-orange color they should be. (There are some original unused tiles still in the garage and a little of the wax has peeled off in the house to reveal the real color.)

They were told that there is no way to get rid of such a build-up of wax, but they could cover the tile with new ceramic tile. I don’t think that is possible because the tiles are thick and not smooth surfaced. Your opinion please! Can the old wax be removed? And can you cover these Mexican tiles with new ceramic tile?

A.    Your son and daughter-in-law can try one of the strippers available for removing wax from tiles, but it is important to know what kind of wax was used to be able to select the right stripper. The fact that some of the wax is peeling may indicate that the wax used is not a paste but a liquid. A local tile store may carry a variety of strippers in increasing strength, but care must be taken not to damage the tiles.

A safer approach would be to have a certified professional look at the tiles and determine if he or she has the needed stripper. Have your son and daughter-in-law go to the Web site of the Institute of Inspection, Cleaning and Restoration Certification:, click on For Consumers, then on the Hard Surface Cleaning followed by clicking on Locate Certified Professionals and enter the information requested.

Restoring the Mexican tiles is better than covering them up with ceramic tiles.

Engineered flooring for kitchen?

Q.    I need to replace the flooring in my kitchen and dining room area. What do you think of the laminates that simulate wood versus real wood versus engineered wood?  I would appreciate any advice you can share.

A.    Wood laminates such as Pergo are very popular but cannot be refinished if they’re damaged, as the laminate is either very thin or only photographed on a wood base. Engineered flooring is made of thin, real wood adhered to a wood core.

They come in two types: A floating floor that is laid over a foam pad, and individual pieces that are either glued or nailed to the subfloor and which can be refinished to a certain extent. Real wood is much thicker and solid throughout.

Of concern in a kitchen is that the additional thickness could affect the dishwasher and any other appliance set under counter tops, locking them in and making replacement a more difficult job (the counter tops may have to be removed).

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.

Replacing tiles over old adhesive

Q.  I enjoy your column and blog, and hope you can provide information on my current situation. My laundry room had 2 layers of vinyl tiles on top of a concrete slab. After removing both layers, there is what looks to be a black mastic adhesive left on the concrete slab.

Tests were done and no asbestos was found. The vinyl was probably installed 30 years ago.

What do I have to do to prep the floor in order to install ceramic tiles, using a mortar mix to set the tiles? Does the adhesive have to be removed? And, if so, what with? Or can I tile directly over the adhesive?

A.    The 30-year-old black adhesive is most likely cut-back asphalt commonly used at that time. It cannot easily be removed chemically or mechanically. The only way may be by grinding or shot-blasting — a very messy method that few will be willing to tackle due to the small size of the project.

However, you may set tile with one of the specialty mortars made by Mapei, designed for use over cut-back mastic. Please keep in mind that the bond strength between the tiles and the concrete, in spite of the strength of the thinset mortar used, will only be as strong as the bond between the concrete and the cut-back adhesive.