November 2021

Wood and Laminate Flooring; Not Ideal on Concrete Slabs at Ground Level

Original article written in 2009 by Lisa Bogo, updated November 2021

The truth is, wood and laminate floors on a concrete slab at ground level are not a good idea in central and coastal Florida. This may seem like a self-serving statement coming from tile specialists, but we’re not alone in coming to this conclusion.

Don’t believe us? Mike Holmes, the home improvement guru of the popular TV series “Holmes on Homes”, isn’t crazy about the idea either … more on this later.

What are the Problems with Wood and Laminate Flooring in Coastal Central Florida?

In a nutshell, moisture.

1. Water Table – Florida has a very high water-table. Concrete slabs absorb water from the ground beneath our homes. Concrete is not a barrier to moisture. If you’ve dug any holes in your yard, you know it doesn’t take long to hit soggy sandy ground. This is why there are no basements here. It’s just too wet.

The images below show a slab in a Suntree home (Brevard County, Florida) that was trench cut to run new plumbing lines in a utility room and kitchen renovation. You can clearly see where the slab starts to show moisture content from the ground under the home. The slab is 8” thick. This photo was taken about 5 hours after the trench was cut.


For scale and visual reference, this next image is the same trench still showing moisture content a week after it was cut and exposed to air conditioning.

Here is another Brevard County home where the slab has absorbed moisture from the high-water table in Florida. Originally, a laminate floor was in this room. A local tile contractor removed it and discovered a large patch of mold seen in the back of the room. In this case, evidence of Florida’s high-water table is seen on the surface of the slab. The darker gray areas indicate moisture in the concrete.

2. Tropical Storms – All too common tropical storms and the rainy season are typical causes of wood and laminate flooring failures due to water intrusion through entrances or seeping through foundations. Florida weather can dump more rain in a short period of time than can be quickly drained away. Even minor flooding will destroy wood and laminate floors. These materials don’t have any resistance to water. Many of the wood floors we’ve replaced with porcelain tile were damaged beyond repair by very short-term flooding.

These photos are of the entry, just inside the front door of the home. The area was subjected to frequent water intrusion from storms.  The Suntree home was built in the late 1990’s.


Mold growth can clearly be seen throughout the underside of the vapor barrier. The lower left darker area is the concrete slab. Black mold and remnants of an earlier tile installation can be seen. Roofing felt was used as an underlayment for the home’s original tile installation – an all-too-common mistake made by previous flooring installers.

The wood flooring was warped and frayed, but didn’t show visible signs of mold on the surface. Mold wasn’t detected until the wood flooring was extracted in preparation for new tile flooring. The licensed tile contractor removed and replaced the failed wood flooring with porcelain tile flooring.

3. Appliance and Plumbing Leaks – dishwashers, washing machines, refrigerators, hot water heaters and plumbing leaks account for many damaged wood floors. A tiny leak under a powder room sink can spread water throughout the ground floor within minutes.


This laminate floor extraction in Titusville shows clear evidence of mold on the surface of the laminate and on the grey underlayment in the photo on left. Mold within the tongue and groove can be seen in the stack of extracted laminate in the background of the photo on the right.

In this case, humidity under a refrigerator was the culprit. Again, the home-owner wasn’t aware of mold until he decided to replace the worn & torn laminate flooring with durable porcelain tile flooring. It was discovered during removal of the laminate and vapor barrier.

4. Furry Family Members – Pet accidents wreak havoc on wood and laminate floors; warping, peeling and curling edges of wood and laminate flooring. Our furry family members account for more damaged floors than you might expect! We’re surprised how often this is a factor in flooring renovations.

In this Melbourne Florida home shown below, the slab at the base board indicates mold in the vapor barrier underlayment. This laminate flooring, along with carpet, was removed after repetitive pet accidents.  Porcelain tile flooring replaced failed laminate flooring.


5. Combinations of Problems – Flooring failures can be caused a combination of water intrusion sources. Flooding at exterior foundations due to lack of gutters, window leaks and irrigation heads directed towards the home are but a few possibilities.

In this case, water intrusion at the foundation and a window leak allowed just enough moisture into the home’s interior carpeted flooring. Damp carpet, a haven for dirt and organic matter, is the perfect habitat for mold and mushrooms.  Yes, that’s right! You are looking at mushrooms (or toadstools) growing in the carpet below.

Vapor Barriers

While moisture is the primary cause of these flooring problems, the secondary cause is vapor barriers.

Because wood and laminate floors absorb moisture, measures to protect these materials must be taken when they are installed at ground level. Vapor or moisture barriers can be as simple as a sheet of plastic or a more complex multi-ply sheeting that acts as a moisture, thermal and sound barrier in one application.

At first thought, a plastic or vinyl sheet barrier installed on top of the concrete slab under the flooring seems like a good idea; however, the barriers do not eliminate the moisture in the concrete slab. As we know, there is a perpetual moisture source in the ground under our Florida homes.

Vapor barriers act much like plastic wrap on top of a warm bowl of soup. Water condenses on the underside of the plastic with no means of escape. It is within this environment that mold has an ideal place to grow, undetected by home-owners.

Unfortunately, wood and laminate floors require these under-layments to block moisture because they are highly absorbent and prone to warping.

During construction, many new homes have a type of vapor barrier installed under the concrete slab to prevent water from accessing the slab. While effective in the short term, the success of these barriers doesn’t completely solve the problem.

Minor flooding and even regular exposure to rain or pool water at entries is a frequent trouble spot. Water drains between the joints, soaks into the body of the laminate or wood and into the vapor barrier. Laminates swell and peel, wood swells and warps and the barrier becomes a home for mold.

In the long run, under ground vapor barriers deteriorate with time. Plastics break down in the environment, become brittle and disintegrate.

What is the Solution?

Florida’s high water-table isn’t going away. We must adapt to our environment and work with it. Concrete slabs absorb water from the ground beneath our homes. Concrete slab construction is appropriate for the Florida environment, however, using the right type of flooring is key. Porcelain ceramic tile is the best type of flooring for the ground level of our homes.

Why is Porcelain Tile a Better Option?

Porcelain tile is impervious and non-absorbent, so water doesn’t affect it. The moisture in the slab beneath the tile escapes and evaporates through grout joints. This moisture is removed from the air in your home by the air conditioning system. Because the moisture isn’t trapped beneath the tile, the possibility of mold is diminished. During renovations, we’ve encountered multiple types of flooring. In every laminate and wood extraction, all have shown some level of mildew or mold in the flooring or the underlayment.

We’ve never seen signs of mold under a tile floor. Tile floors are usually replaced for a handful of reasons:

  1. Faulty or improper installation
  2. Inferior tile that is failing
  3. Clients desire to upgrade or make aesthetic changes

To hear what Mike Holmes of the hit TV series thinks about wood or laminate on ground level concrete, check out Season 4,. Episode EP4046 “Best Laid Plans”.  Mike Holmes says wood flooring should never be installed on ground level concrete. We agree. If you want natural wood flooring, we suggest using it only on suspended floors. In Florida, this means second floors and higher.

 Want the Look and Feel of Wood?

There are hundreds of porcelain tiles that look like wood available through Atlantic Tile Distribution. Visit our showroom on Ellis Road to learn more.



November 2, 2021

TILE PRO SPOTLIGHT; Joseph Mattice of On the Level Flooring in Simpsonville, SC

We like to share insights from other tile professionals across the U.S. In this instance, we’re featuring a common sense article written by Joseph Mattice of On the Level Flooring in South Carolina. The information presented in Joseph’s article is relevant to tile contractors and home-owners alike.

Home-owners benefit by learning to differentiate between two types of tile projects; tile setting and tile assembly.

An example of tile setting is a floor tile installation when proper floor prep is performed by other trades. The tile installer is tasked with the layout and installation of tile.

A tile assembly is best illustrated in the complexities of building a wet space or shower.

Home-owners will gain understanding of the costs associated with each distinct category. Additionally, home-owners learn how to discern the expert in construction of a wet space or shower. They will be armed with the knowledge required to compare quotes and proposals.

“Understand the Crucial Difference Between Setting Tile and Building a Tile Assembly”

Written by: Joseph Mattice; On the Level Flooring

When you bid a job, what are you selling? Are you simply setting tile or are you building a custom tile assembly that you can set tile on that will last?

When you walk onto a site for a consult with a client, you determine how the building is constructed. You may feel the floor roll underneath your feet or in the bathroom, you may smell musty air and see swelling wood. The client asks “how much will it be to lay some new tile here?”

We’ve all heard that question. It’s a simple question, but for skilled installers, it is not a simple answer.

In those quick moments, a skilled tradesperson might have determined that they will need to demo the entire bathroom to studs, replace rotted joists, install new subflooring, flatten the floor, flatten the walls, cover them, waterproof, and install underlayment. All that before you can “lay tile.” Are you able to explain and present that to your client so that you can sell your value? More important still, do you understand the difference between installing tile and building an assembly?

TCNA B422-19
Tiled Shower; Materials Assembly

What is a Tile Assembly?

As yet, there is no official definition of this term, but generally speaking, a tile assembly can be thought of as a collection of components from structure to finish that directly relate to the performance of the tile. Not every component is necessarily done by the tile contractor, but they will all have an impact on the success of the installation.

Let’s take method TCNA B422 in the TCNA Handbook for Ceramic, Glass and Stone Tile Installation as an example. This is a common installation in a shower. While a client might assume that tiling a shower consists of just setting the finish product and grouting, a diagram like this reveals the true complexity of an assembly in a common situation. There are a minimum of seven components in this diagram that are part of the tile assembly. This is completely aside from the design and layout of the tile pattern itself, which is an art in its own right. The correct type of drain, the right bonding mortar, the backing or substrate, membrane choice, appropriate sealant and location, wet area-approved tile, the sloped bed. If any of these steps are improperly executed – or components improperly installed – it could put the entire assembly at risk. Each component requires knowledge of the correct material to use and the method of installation, as well as the order of installation and appropriate cure times of the various materials. Add in niches, benches, and other custom touches and the need for someone who understands these details grows more and more apparent.

Why is it Important ?

When we understand all the components of an assembly, it helps us in several ways.

First, it will ensure the highest chance of success in our installations. Getting things right at each step adds to the lifecycle of the tile assembly.

Second, it allows us to charge appropriately for the work and time it takes to do it right. If we bid a job without understanding everything that we will have to address, we open the door to lost profit, which is the downfall of any business, large or small.

Third, in educating our clients it gives them the opportunity to make sure that they are getting truly comparable bids. If they understand what goes into an assembly, they will be empowered to make an informed choice as to who they hire. And the person who was the expert and educated them will always be top of mind.

Fourth, when presented with a project drawn up and specified by a design professional (i.e. an architect or structural engineer), understanding the exact terms and limits on where your work begins and other trade’s work ends is invaluable.

Predictable Performance Protects Profits

An underrated advantage of understanding what goes into your assembly is that your installations will perform predictably. This is one reason manufacturers recommend specific products, because they know how they will interact, what the different components do, and the long-term interactions between them.

If you take the time to learn about different parts of an assembly, that will make you a more flexible installer, more efficient, and better able to know how to adapt your knowledge and expertise to new challenges. And it will also enable you to take on installations that you might not have experience in. The resources we have at our disposal such as the TCNA Handbook for Ceramic, Glass, and Stone Tile Installation, the NTCA Reference Manual, and the ANSI A108 documents – in addition to the education we can access from major manufacturers and the Ceramic Tile Education Foundation – are powerful tools we can use to further our businesses, as well as our skills.

So, what are you selling? What are you installing?



November 2, 2021

The Right Conditions; Use Constitutes Acceptance

By Donato Pompo, President of Ceramic Tile and Stone Consultants, Inc

ANSI A108 states that a tile installer must inspect the surfaces and conditions of a job before proceeding with a tile installation. If there are any conditions that would prevent a satisfactory tile installation, then the work should be suspended, and the tile contractor should notify the owner’s representative in writing.

This can be an opportunity that leads to extra work, which means more money for the tile installer. For example, if a substrate needs to be corrected to meet industry standards, this increases the bottom line.

Beware! “Installation Constitutes Acceptance,” as quoted in all product warranties, puts the liability on the installer, because if anything goes wrong after-the-fact, the tile installer ends up with the problem in their lap!

Remember, expensive failures can be avoided when problems are identified before the tile is installed!