Floor Repair and Installation Q&A

Be sure to scroll down... there may be more than one question on this page!

Dear NH,

I want to install tile inside the front door of my house. I have an ugly square of linoleum there now. When the tile installer came to look at the job, he said that I couldn't install tile because the bottom of the door would hit the tile after he installed some new plywood and the tile. The door is steel and he said it can't be cut. What can I do?

BB from Peekskill, NY


You have a number of options. The first and most difficult is to modify or replace the existing door assembly. If you want to use your existing steel door, then the door and jamb assembly must be removed and reinstalled high enough so that the door will clear the floor. This might require some modification in the framing above the door, also. Obviously you will need to do trim replacement and painting/staining both inside and outside the frame.

Another option is to replace the steel door with a wood door, which can then be cut at the bottom. However, if the new gap between the door bottom and the original threshold is too wide for bottom weatherstripping, you may have to cut out the original threshold and install a "generic" threshold slightly raised to accommodate the shorter door.

If you have access to the basement or crawlspace under the floor, you could reinforce the floor with plywood from underneath, or even install a reinforcing post to stiffen it up.

The a less labor-intensive solution would be to use a different flooring material for your entryway. Of course, installing fresh new vinyl flooring is one obvious option. Another is to use slate instead of tile. Slate flooring can generally be installed over thinner floor surfaces than ceramic tile because it is much less prone to breakage over typical 3/4" plywood. Another option is tongue-and-groove laminated flooring. It is often used in kitchens and bathrooms because of its durability and is available in a wide range of styles from simulated wood to subtle colors.


Dear NH,

We have particleboard as the floor surface beneath the carpet now. We want to install self-adhesive tiles.  I was told this should not be a problem by one person (the fellow at the home improvement store), then someone else (the guy who was trying to talk me into having his group do the professional installation) told me that I needed to put down more plywood then install the tiles. Neither person has actually looked at the subflooring materials. How do you know when the surface is too rough for the tiles to stay in place? We are on a tight budget for this project and I can't afford to spend unnecessary funds for unneeded materials.

NC from Oxford, NC


There are two potential problems in installing self-stick tiles over a subfloor. One is the smoothness of the subfloor. To be blunt, the floor should be absolutely smooth!   The reason is because any irregularities.. lumps, bumps, seams, nail holes, etc...  in the subfloor surface will be transferred through to the tiles over time. This is true of vinyl tile installation over any surface. Even the pattern of a textured sheet vinyl or linoleum floor will appear through the self-stick tile! Now if you are only talking about a imperfections or nail-heads, these can be easily repaired by patching with a quality wood filler or floor leveling compound. Don't use wallboard patching materials because they may not be hard enough. Sand surface smooth, vacuum and damp-clean to remove all dust before tile installation.

The second problem is at the seams of the floor. If there is any "flexing" or movement at the seams, the tiles will eventually crack across these seams. In most situations, the easiest way to firm up the floor is to install a layer of 1/4" plywood over the subfloor (nailed or screwed and glued) in such a way that the new plywood seams do not lay over the old seams. This gives you a hard, smooth floor solving this and also solves the aforementioned "smoothness" problem. The nail or screw heads should be "set" below the surface of the floor and the holes filled.

I think the pro was wise to suggest the additional plywood, since he is well aware of the problems associated with poor subfloor preparation. He also knows that, time wise (since his time is money), it could very well take longer to repair a bad floor than to just cover it with plywood. This may not be true in the case of a do-it-yourselfer such as yourself, since you are looking to save money, not time!

Dear NH,

My 15-year old, but in good shape hardwood floor has some loose planks. It is laid over a concrete slab and I believe some of the planks have lost their adhesive bonding to the concrete. Maybe from moisture seeping through the concrete although we only get about 9 inches of rain in a year (this happened before El Nino) and the most affected planks are far way from the edges of the slab. The tongues-and-grooves hold them in place, but they move vertically. I thought about drilling small holes and injecting glue. Will this work?

RR from Encinitas, CA


Before I begin, just a comment. I discourage anyone from gluing any flooring material to a concrete slab that meets the soil. This is simply because few adhesives will form a lasting bond when subjected to the type of moisture that can rise through a slab. Though new homes usually have a vapor barrier installed underneath the slab to keep ground moisture away from it, these systems are not perfect and there is, of course, human error.

Today the manufacturers have gotten flooring installation down to a science with special products designed for use under these difficult conditions. For example, there are special tongue and groove wood floors that are installed over a special paper. The literally "float" over the substrate using no adhesive at all!

Back to your question… you just couldn't inject enough glue to make a lasting repair. Plus there is probably dust and dirt under the floor that would prevent the glue from sticking well, even if you could inject enough. The only lasting repair I know of is to take the loose sections of floor up, clean all dust and dirt from the slab and reglue. You will have to sacrifice at least a board or two to free up the others in the loose area. Here is a short description of the procedure...

First, you will have to remove one or even a few of the strips to release the rest from the tongues and grooves. You should be able to decide which and how many pieces to remove by looking at how they overlap.

Drill a number of holes into a selected strip. Then break it into pieces with a wood chisel and remove it. Another method would be to use a hand circular saw with the blade set so that it does not penetrate the boards completely... again breaking the strip up. PLEASE be careful with the depth setting of your circular saw and also with your drilling... the concrete below will destroy drills and saw blades and, even worse, a circular saw may lose a tooth or kickback! That can hurt!

Now that you have removed the loose flooring, the following steps should be followed:

(1) clean up any dust or debris under the floor.

(2) apply a flooring adhesive to the floor and also apply a thin coat (called "buttering") the back of each strip right before installation.

(3) Install the replacement flooring, piece by piece. You can start from either side, but I have found that starting from the side that has a "tongue" rather than a "groove" makes for a slightly easier repair. However, I understand that may not be possible in some situations.

(4) Apply enough adhesive to the floor to get a good bond, but not so much that it squeezes up between the boards. Using a notched trowel is recommended… the size needed is normally indicated on the can of adhesive.

(5) On the final piece or few pieces you install, you will most likely have to cut off the bottom of the groove and/or the tongue prior to reinstallation, depending on the order in which you re-lay the flooring. You might also find that they will not quite fit any more, and you may have to slightly shorten or even rip a strip or strips to make them thinner (with a table saw).

(6) Since the flooring is likely to expand and contract, you should not make the fit extremely tight. Instead the pieces should fit into place without any forcing.

(7) Get out that 3000 page Websters New Universal Unabridged Dictionary, that old Sears Catalog, and a few rusty barbell plates... they will make good weights to hold down the tongueless-or-grooveless pieces until the adhesive dries.

Hope this is somewhat helpful. Each repair of this type is different and I can't anticipate all the possible contingencies such as molding removal, radiators and other obstructions. Nevertheless I think I have covered the basics to get you started.

Dear NH,

Just a quick comment. I have been laying hardwood flooring for 15 years, my father longer and grandpa… well, he won't tell!

To the point; you are the only place I have ever seen that tells exactly what and what not when it comes to hardwood flooring. We have been trying to tell the maids and cleaning crews that they are destroying our wood floors with the over-spray from whatever cleaning chemicals they use. Normally we two-coat the floors with a protective finish, and then apply a final coat when the house is done . We are forever getting chemical reactions when applying the final coat because of chemicals that end up on the floors. The problem is that these chemicals are not easily detectable.

Well, to prove our point may we please have permission to print several copies of your page and give them to these bozos who don't have a clue… nor do they care on how hard of work sanding the floor is. Who knows… maybe we might even finally get paid for our back charges of the re-refinishing we have had to do. If so I will send you your cut. Great work thanks again

Rich Brown of "Rich's Custom Floors"


I'm glad the information was helpful. The article you refer to, at https://www.naturalhandyman.com/iip/inffloor/infrefinpoly.html, was supplied to us by Hal Rusche 2nd, president of Heritage Hardwood Floors at http://www.cinhome.com .
Like many other homeowners, I was blissfully ignorant for many years regarding problems caused by various cleaning and coating products, even those supposedly designed for floors!

Whenever I can find something of value to the home repair aficionados in my readership, I like to get the word out. We publish a variety of home repair info that is not always widely available, as well at the "nitty gritty" stuff.

If you need to use the article to amplify your point, feel free. Just leave the info concerning the site name and URL on the pages you print.

Dear NH,

We have a laminate floor in our kitchen and dining room. Then, our dishwasher hose developed a leak, but we didn't know it. We don't even know how long it had been broken… months, we guess!

The laminate flooring started to warp and that is how we found out something was wrong. We want to put down a new floor but the subfloor has been wet for quite some time and now, after being exposed, smells really bad. We are trying to dry it out, but how do we get rid of the smell



The odor is being caused by mildew that has grown under the flooring due to the excessive moisture. Drying out the floor is the first step and it should eliminate much but possibly not the entire odor. This drying process could take a week or two, so be patient (I know it's tough to live with the mess but hang in there!). Using fans and keeping the heat up can speed things along. If the subfloor is warped even slightly you must replace it. If the subfloor is still flat, there are a few steps you can take to lessen or even eliminate the odor.

There may be areas that have become wet that will not dry very quickly, such as underneath the cabinets surrounding the dishwasher. If the dampness appears to extend under them, you can try to remove the kick-boards under the cabinets to allow air to circulate. Be careful doing this, since the cabinets can be damaged. If your kitchen has vinyl cove moldings under the cabinets, they will cover any new wood that may be needed to replace the kickboards. I can't offer any specific guidance on this procedure since it depends on the construction of your cabinets. Also, if the flooring is partially in the way removing the kickboards may be more difficult or impossible. Eventually, all the flooring will dry up, even under the cabinets. It will just take a lot longer to do so!

Once the floor is thoroughly dry, wash it with a mildew-killing solution of one cup of chlorine bleach to one gallon of hot water. Let it soak into the surface of the floor for a while (ten to fifteen minutes should do it) before rinsing it off. Again allow the floor to dry thoroughly. This should eliminate much of the odor. Try not to get the bleach mixture on any finished surfaces such as cabinets… unless you need to clean them also. Most modern finishes will not be permanently damaged by the bleach mixture but, if you are unsure, wipe them off immediately or just keep them dry in the first place!

If your laminate flooring is "loose-laid" or "engineered flooring" which does not use an adhesive, you can take the additional step of sealing the subfloor with any quality clear wood sealing product, such as Thompson's Water Seal. This will further seal in the residual odors from the mildew. Just check with the manufacturer of your flooring to be sure that this will not cause any compatibility problems with the flooring. It probably won't but it's always good to check!

If your laminate floor is fully glued down, the adhesive should offer additional odor protection so sealing the floor is probably unnecessary or, again depending on the manufacturer's recommendations, even undesirable!

Dear NH,

Should I be concerned about asbestos when removing old vinyl? I see no reference to this in your current postings on asbestos.

AR from Carrollton, GA


You can only know for sure by having the floor tested by a certified testing lab or purchase a do-it-yourself asbestos test kit at a hardware or home store. However, if the floor is less than 30 years old you can be reasonably sure that it has no asbestos in it.

As mentioned in my article on asbestos, there are different types of asbestos and not all asbestos is dangerous. That having been said, ALL asbestos removal should be done by professionals, since the particles can get into everything in your home if special care is not taken.

In many cases, it is better to cover the old flooring rather than removing it. This is done by installing a 1/4" layer of plywood underlayment over the old floor. Then, any type of flooring material can be installed over it. Using both screws and construction adhesive to attach the underlayment will provide the strongest floor.

Laminated flooring, such as Pergo, can be installed over sound vinyl or linoleum with no plywood underlayment. This cost savings may be one reason why laminated strip flooring has become so popular!

Dear NH,

We have just installed a plywood subfloor in our kitchen. Is it necessary to do anything to the seams between the sheets before we install vinyl composition tile? Thanks for your time.

CH from Mohawk, New York


It is most important that the floor is flat with no raised defects, nails or screws. Also, there should be no gaps of more than 1/16" between the plywood sheets. Either of these conditions could cause failure in the floor. The reason for this is that vinyl tiles tend to follow the contour of the floor below. Over time, tiles over gaps may crack or break along the line. Unfilled holes will be weak spots that may over time be visible as the tile settles into them.

If there are gaps, use a floor leveler to fill them. This product is available at hardware or home stores. Follow the mixing instructions, apply it to the floor and allow to dry. Use the same product to fill nail and screw holes. Sand smooth when dry.  Be sure that the floor is absolutely dry and dust free before applying the tile.

Dear NH,

I live in a mobile home and I have to replace some flooring. I mean total replacement right down to the sub-flooring. Is there any kind of tool that I can use to cut out the flooring under the walls? The reason I ask is that the seams for each of the floor panels meet directly under the bottom support for the walls. Would I have to remove each section of wall (for each room that I'm working in) in order to be able to replace the flooring?

GS from W. Palm Beach, FL


There is no tool that can completely remove flooring under a wall. Many wood-framed homes are built similarly, with the interior walls raised over the subflooring as each floor is constructed. Removing flooring under walls destabilizes them and is unwise.

Instead, use a reciprocal saw or jig saw to cut the flooring out as close to the existing walls as you can. Be careful not to cut any supporting members! Then, install cross supports as necessary to reinforce the flooring along the edge of the room between the floor beams. You may be able to use metal joist hangers such as those used for deck construction to make your cross supports extra sturdy. They are available for lumber as small as a 2x4.

It is not necessary to position the cross braces right next to the walls since there is typically little weight stress there. Allow yourself a few inches to work your hammer or screw gun.... the job will be much easier with less knuckle banging and fewer expletives!

Dear NH,

I read your article on removing linoleum from regular floors... (https://www.naturalhandyman.com/iip/inffloor/inflino3.html ...
but how do I remove it from a concrete floor? The flooring is fully bonded. I've tried scraping but make little progress.

MD from Peoria, Il


I have to ask the obvious question (at least to me) ... do you really need to remove the old floor? Most flooring materials can be installed right over well-bonded linoleum, including vinyl flooring, ceramic tile, carpet and laminated flooring. If

You can open a hornet's nest IF your old linoleum contains asbestos. I suggest finding a local testing company and having a sample of the floor tested. If it does contain asbestos, covering it might be the only sensible option!

If removal of the old floor is absolutely necessary, the use of a heat gun along with a putty knife can speed things along. The heat will soften both the linoleum and the adhesive. As mentioned in the article, slicing the flooring into manageably-wide strips first will make the going easier.

How clean you ultimately need the floor depends on the flooring you are going to install. For example, you don't need as clean a floor for carpet... the padding will keep the old glue away from the carpet. "Floating" laminate flooring uses a paper-like floor cover that will separate the flooring from the glue.

But if the new flooring requires gluing, you will have to scrupulously remove all old adhesive. Though hot soapy water and lots of scraping will sometimes get the glue off, you might have to resort to a solvent adhesive remover. These products work very well BUT are toxic to inhale and very explosive. Be sure to follow all instructions, have adequate ventilation and be sure all sources of flame (such as pilot lights) are extinguished before starting.

Removing a glued floor is rarely fun and rarely easy. Just keep your eye on the big picture... such as the one on the wide-screen TV that will rest on your beautiful new floor!

Dear NH,

I recently installed a hardwood floor in part of my home. My intent was to match it with the existing hardwood floors throughout. I used wood filler on the new floor and I really like the finish but the existing floors have been finished without wood filler. The finish is a water-based urethane that looks dull. Do I need to resand completely before using a wood filler and new finish or can I lightly sand with screens and a buffer. I am really not looking forward to the work and mess of a major floor-refinishing job. But I want the old floor to look more like the new part. I was advised to not use a filler when I refinished the old floors 4 years ago, now I regret heeding that advise. Any suggestions?

WP from Evansville, IN


Water-based urethane will stick to most old work (and itself) as long as the surface is clean, thoroughly dulled and totally free of grease or wax. Urethane can be recoated many times before stripping is necessary. I suggest you check your manufacturer's label to see what their recommendations are.

I can't see any reason why you couldn't use the filler prior to refinishing the old areas. There is the slight chance that it may lift out in spots (it would stick better to raw wood) but I think overall the effect will be worth the risk. Do the filling after the first sanding of the old floor. Then resand to level the filler to the floor and stain, followed by the urethane (again, according to manufacturer's directions).

One option that is usually not discussed in floor refinishing is the use of a chemical deglosser, such as Wil-Bond, on urethane. I have found it to be very effective in dulling many types of finishes. However, the problem with using it on floors is the buildup of vapors in the room. Forced ventilation is essential and all sources of sparks must be eliminated for safety reasons. You could experiment and see if this product might hold some value for you in this job... specifically in preparing the floor for filling. Test on a small area... if you find significant dulling you might want to use some Wilbond prior to filling. One thing to be aware of is that Wil-bond can remove finishes that are very fresh.

For sanding purposes, renting a commercial floor machine with screen pads will make fast work of this job. Use a grit of 100-150, starting with the 150 to see if you get an adequately dull floor. This isn't progressive sanding... from rough to fine grit... this is simply to dull the finish. The old floor finish must be totally dull or you may have adhesion problems, so be thorough. Use a sanding block to get into corners the circular pads can't reach.

Dear NH,

We recently found out that a portion of our kitchen subflooring is rotting due to a leaky sliding glass door. This floor is over a walkout basement. You can actually push your finger up through the rotten flooring (from the basement) and touch the kitchen floor vinyl. Our question is, can we possibly replace this subflooring from below... or do we have to remove or pull back the vinyl, replace this subflooring and then somehow replace the vinyl? Is there a way to pull back the vinyl to do a repair underneath? My husband is very handy, but this is a new one on us! Thank you!

RM from Lawrence, KS


Every homeowner will eventually run into something rotten! Every repair is unique and few have painless fixes. First, the pain. No, you cannot make a repair from underneath. Also, the vinyl cannot be reclaimed so a repair of the finished floor will have to be made.

If the rot is primarily in the subfloor and has not extended to the supporting floor beams or "joists", the repair is simply to cut out the rotten area and replace it with a plywood of similar thickness. You will most likely have to install additional framing or cleats to support the edges of the smaller piece. This of course varies job by job.

If the rot has extended into the joists, you will need to determine the correct repair... too extensive an issue for this forum. Simply, if the rot is very minor (you might need a pro to determine this for you), you might not have to do anything. Once the source of moisture is gone the rot will likewise stop growing. Extensive rot could require anything from reinforcing the affected beam to some major structural carpentry.

Implicit in your question is the repair of the finished floor. If the rest of the vinyl floor is in good shape, you can save a little money by being creative. Instead of using vinyl in front of the slider, consider using slate or another durable flooring product in this area. If done properly, you can make it look like planning, not repair... a cool place to leave those dirty shoes and boots.

It's worth considering!