Your Ultimate Guide to Installing Engineered Hardwood Floors
Learn What the Pros Know: When to Glue, Nail, or Float…and How to Avoid the Three Negative R’s of Construction!
The generous use of hardwood flooring throughout the home is one of the hottest design trends in residential architecture in recent years. Both interior designers and homebuyers have re-discovered the warmth hardwood flooring brings to the interior of a home. The natural material brings a sense of balance and synergy.
Residential builders have found that newer products, such as engineered hardwood flooring, can be simpler and more cost-efficient to install than traditional hardwood. Engineered wood floors provide amazing alternatives to other types of flooring material, but they are not free from potential challenges.
This article shares some best practices for installing engineered hardwood floors. The first best practice is thorough planning. Investing time up front to plan your installation project is well worth it to avoid the Three Negative R’s of Construction: Repair, Revise, and Redo!
8 Questions to Answer Before Getting Started
Installing an engineered wood floor is a major project. Treat it with the respect it deserves. Here are the eight critical questions you must research and answer to plan and budget for a successful engineered hardwood flooring installation.
1. What are the best-engineered hardwood floors to lay over your concrete slab?
Engineered hardwood products vary in-depth, typically ranging from three-eighths to just over half an inch thick.
Thinner material can be more cost-effective and is advantageous if overall floor height is an issue. Premium grades have a thicker wear layer, which offers more opportunities to be sanded and refinished, extending the life of the engineered wood flooring.
2. What type of subfloor surface will lay beneath the installed engineered hardwood?
You need to understand how to prepare the subfloor surface, which varies a bit based on the type of subfloor surface.
All surfaces should be scraped and cleaned until they’re free of any debris. Subfloor surfaces must also be dry, solid, and structurally intact.
Concrete subfloors should be as flat as possible in accordance with the manufacturer’s tolerances (an eighth-inch across a ten-foot area is a good industry standard).* Concrete floors also need to be at the manufacturer’s specified relative humidity (RH) level to the flooring you’re installing. You can officially confirm and document the subfloor’s RH level in accordance with the ASTM F2170 standard for determining in situ RH in concrete slabs.
If you are installing over a wood subfloor, the moisture content percentage (MC%) must be measured and verified appropriately. The subfloor surface should be firmly secured with no loose material. If this can’t be achieved, it may be necessary to replace or overlay the existing subfloor surface.
3. Should you float, nail, staple, or glue your engineered hardwood?
There are different factors that come into play when making this decision. It depends on the type of surface over which you are installing the floor. It also depends on the environment where you live. Is this a retrofit or new construction?
You should install a floating engineered hardwood when you need flexibility. Installing a floating engineered hardwood floor works well at any grade level and over most types of subfloor surfaces. A floating engineered wood flooring installation on concrete can be an excellent choice if your subfloor is below grade. It’s also a great option if you choose to incorporate a radiant heat system.* (Don’t forget the vapor retarder!)
In contrast, gluing hardwood to concrete provides you with a very permanent solution. Gluing works well when you are installing engineered hardwood over a concrete subfloor, but be sure you clearly understand the manufacturer’s application instructions before you glue that floor.
Plan to nail down the engineered hardwood flooring when you have a wood subfloor. As long as you use the correct pneumatic nail gun, this technique provides the installer with a simple and controlled approach to the installation.
4. What’s the best glue for your engineered wood flooring?
Whatever glue product recommended by the manufacturer. Different types of glue work best with different types of flooring. Environmental factors also play a part. Avoid adhesives that are water-based, as they trigger expansion and contraction of engineered wood products. A good adhesive forms a powerful bond yet remains flexible over the long haul.
5. Will a radiant heat system be incorporated under the engineered hardwood flooring?
If so, engineered wood flooring is an attractive option here. The manufacturing process of the engineered wood creates a stable core that resists expansion and contraction from environmental changes. Verify that the radiant heat system you are considering is compatible with engineered wood flooring. Have you planned to install your engineered hardwood in a way that is compatible with a radiant heat system? For example, nailing down or stapling an engineered hardwood flooring over a radiant heat system takes special care. Always consult both manufactures in the planning process.
6. What sort of moisture testing will you conduct before installation?
It is important to test the moisture content (MC %) of a wood subfloor. It’s also important if the subfloor is concrete to properly test the relative humidity (RH). Don’t forget also to test the engineered wood products you intend to install. Excess moisture is the surest way to a flooring failure.
7. Do you have the appropriate space, time, and conditions to acclimate the engineered wood flooring?
Engineered hardwood needs to acclimate, but different manufacturers require different things. Always consult the specific manufacturer for their requirements.
After your engineered wood products have been delivered, best practice dictates maintaining serviceable conditions within the building for approximately five days. Place open cartons of the engineered wood in the center of the room to promote adequate air circulation, while avoiding exposure to direct sunlight. This placement helps to minimize expansion and contraction, which reduces the risk of moisture-related warpage.
8. How much time, effort, and money will the project take?
Engineered hardwood installation costs vary. Materials range from three to $13 per square foot, depending on the grade of the product. Installation costs run anywhere between $3 to $10 per square foot, depending on the complexity of the design.
If you are a homeowner, you may also be asking yourself whether you can save money by doing your own installation. Perhaps. The more pointed question you have to answer is whether a reduction in upfront dollars spent will be worth your sweat equity time you’ll invest to achieve an inexpert installation – especially when compared to your lower total cost of ownership incurred by engaging a flooring professional. Get a few professional bids. Analyze the costs of labor and materials against services and warranties offered. Then make your choice.
Don’t make assumptions – do the research and read the instructions.
You’ll need a lot of information to answer these questions in detail. Yet this information is necessary to increase the chances of a successful engineered hardwood flooring installation.
Once you’ve selected an engineered hardwood product, your starting point for any question is to consult the manufacturer’s guidelines. Congratulations if you figured out how to install your Wifi network or put together Ikea furniture without looking closely at the instructions. That approach won’t work here.
The best way to install engineered hardwood flooring is to follow the manufacturer’s instructions closely. Always remember:
Different products have different specifications – even products from the same manufacturer.
Don’t make the dangerous assumption that all a manufacturer’s guidelines for preparing the surface and installing any of their products are the same. Be proactive and ask questions. This guide is the perfect starting point for building your list of questions.
If you are a weekend warrior, it just might be a good idea to engage the assistance of a flooring expert. Consider your own history: Is this your first major flooring project or do you have some experience?
Checklists to Make Installation Easier
We’ve put together four checklists to help make your engineered hardwood flooring project a bit easier. The first checklist applies regardless of the installation method. Each one of the other three checklists addresses a different installation option: gluing, nailing or floating.
Managing the subfloor
- Assess and prep the subfloor surface. Scrape and clean the surface, making sure to remove all debris.
- Make any necessary repairs on the subfloor.
- If a concrete subfloor is in place, conduct an RH moisture test on the concrete according to the ASTM F2170 standard to verify its readiness for installation.
- If a wood subfloor is in place, measure the moisture content percentage (MC%) of the wood subfloor and the engineered wood flooring to confirm all the engineered hardwood is acclimated and suitable for installation.
Handling the engineered hardwood
- It’s critical to unpack and acclimate the engineered hardwood flooring under monitored conditions.
- Be careful when laying out the engineered hardwood flooring material. Ensure that joints have appropriate offsets and that you avoid discernable patterns.
- Check to make sure that the subfloor is flat within a minimum of an eighth inch over a ten-foot span.* If needed, apply a floor leveling compound to mitigate variances.
Glue It: The Most Permanent Solution
- When selecting the starter wall, consider the grain of the engineered hardwood, as well as how light may affect the perspective.
- Snap a line or use some sort of straight edge to ensure that boards are lined up straight.
- Allow spacing (typically a minimum of half an inch) for expansion on all perimeters, per manufacturer specifications.* Consider using half-inch spacers to maintain consistency.
- Trowel spread the glue in a predetermined area. Avoid spreading wider than 36 inches as it may dry faster than you can install, which can create a potentially messy situation.
- Secure the planks in place during installation so they don’t shift out of alignment. You can assert downward pressure on the planks by rolling the flooring using a 150-pound wheel roller. A simpler option is to set five-gallon buckets filled with water on the planks.
- The bottom line is that you want broad, uniform contact between the flooring material and the adhesive.
- Always clean excess adhesive before it has a chance to dry.
- Finish by installing baseboard and trim products.
- Important “Don’ts”
- Don’t use a rubber mallet as it can damage the flooring. Do use a tapping block to fit the planks snuggly.
- Avoid any heavy foot traffic for at least 24 hours.
Nail It: Using the Right Tools on a Wood Subfloor, Nailing It Is a Fast and Simple Option
- Choose the correct pneumatic stapler or “brad” nailer to install your engineered hardwood product.*
- Snap a line or use some sort of straight edge to ensure that boards are lined up straight. Allow spacing (typically a minimum of half an inch) for expansion on all perimeters, per manufacturer specifications.* Consider using half-inch spacers to maintain consistency.
- Follow the flooring manufacturer’s guidelines for best practices on securing (nailing or stapling) the engineered wood to the subfloor.* Tighten using a mallet and wood tapping blocks.
- Install the baseboard and trim products last.
Float It: The Option with Maximum Flexibility
- Install an appropriate underlayment according to the manufacturer’s guidelines.*
- Install your space blocks. Half inch blocks are typical, but check the manufacturer guidelines.*
- Set your chalk line mark, apply the adhesive, and lay the first board in place.
- When installing a floating engineered hardwood floor, it can be tricky to snug up the tongue and groove joints. You can use five-gallon buckets of water to put pressure on the floor to keep the boards in place. Be careful not to spill any of the water as you don’t want to add any moisture to the flooring.
- As you install more rows, use blue painter’s tape to keep the joints tight.
- Use a hammer and block to gently tap the joints tight. Keep the first row straight and square with the room.*
- Regularly wipe any excess adhesive with a damp, clean cloth so it doesn’t get a chance to dry.
- Continue with these installation steps as you move through the room.
- Install the baseboard and trim products last.
And one critical “Do” for every installation option: Every few rows, step back and look at everything that’s been installed already: Are the rows straight and square? It is much easier to fix a couple of errant rows than an entire room.
Addressing Moisture Control to Avoid an Engineered Hardwood Floor Project Nightmare
It is vital to test the moisture levels of the subfloor and the engineered wood flooring products properly. Moisture impacts the engineered hardwood flooring regardless of whether the subfloor is wood or concrete. Excessive moisture permeating from floor slabs after installation can cause floor covering system failures such as debonding and deterioration of finish flooring and coating and microbial growth.
For relative humidity testing, use the proper depth for testing.
The ASTM F2170 standard is quite clear on the depth of moisture testing of concrete slabs. The in situ method of testing (ASTM F2170) provides relative humidity (RH) measurements at 40% of the slab’s depth,* a position proven to more accurately portray the final RH levels of the slab if it were to be sealed at that point in time and the slab moisture allowed to fully equilibrate. In this way, in situ measurement provides a composite picture of overall slab moisture levels and provides the data necessary to make business decisions regarding flooring installations.
Proper acclimation of engineered wood flooring products is vital to managing moisture.
Prior to installation, the engineered hardwood flooring needs to acclimate according to manufacturer’s specifications.* Engineered wood acclimates by being allowed to breathe within a controlled environment. Proper acclimation helps to minimize moisture-related warping as well as expansion and contraction.
To set the conditions for proper acclimation, have the engineered wood flooring products stay onsite under serviceable conditions for up to five days after delivery.
Always Double-Check Your Work
Benjamin Franklin’s axiom applies whether you’re a seasoned flooring professional or a weekend warrior looking to tackle a new project:
“An ounce of prevention is worth a pound of cure.”
The prevention of potential issues starts by answering the eight project pre-planning questions in detail. Then, review the appropriate installation checklist.
Last, always consult the manufacturer’s specifications regarding moisture level tolerances of the engineered wood flooring products, as well as the subfloor. These specifications can provide you with guidelines to help ensure that you have long-term engineered hardwood flooring success. Manufacturers of engineered wood have a variety of installation protocols and suggestions for their products. Following their best practices provides the best roadmap for your flooring project.
*Always check with the manufacturer’s specifications and a flooring professional if possible!
“As Seen in Tomorrow’s Contract Floors magazine”
Jason has 20+ years’ experience in sales and sales management in a spectrum of industries and has successfully launched a variety of products to the market, including the original Rapid RH® concrete moisture tests. He currently works with Wagner Meters as our Rapid RH® product sales manager.