Trowel vs Glue for Engineer Hardwood Adhesive (Explained)
Gluing down engineered hardwood delivers a smooth, seamless finish. However, the installation process must be done correctly to avoid issues like hollow spots, loose planks, and squeaking. Choosing the right adhesive method is critical. The two main options are:
- Trowel: Spreading adhesive using a trowel with a notched edge.
- Glue: Using liquid adhesive in a bottle applied directly to the subfloor.
Trowelable adhesives create a tighter bond with the texture left by the notched trowel. Glue adhesives are easier to spread over large areas, but may not adhere as tightly. This guide will delve into the pros and cons, helping you determine the best choice for your project.
Advantages of Using a Trowel
Trowelable adhesives offer some key benefits:
Precision Spreading
Notched trowels allow adhesive to be spread evenly at the right depth. The notches leave behind ridges of adhesive that collapse when the flooring is laid. This creates a tight mechanical bond.
Maximum Grip
The texture left by a trowel results in greater surface area for the adhesive to grip the subfloor and flooring. This creates a stronger bond and reduces hollow spots.
Versatility
Trowels come in different notch configurations to suit the flooring type. You can also adjust pressure on the trowel to vary ridge height.
Long open time
Troweled adhesive remains tacky for 45-60 minutes generally, allowing time to lay flooring properly. Slow setting gives more working time.
Reduced adhesive usage
The notched edges help spread adhesive thinly and economically while still getting full coverage. Less adhesive is wasted compared to pouring liquid glue.
Moisture barrier
Some trowel-on adhesives contain moisture barriers ideal for concrete subfloors. This added protection prevents moisture damage.
Professional finish
A trowel gives greater control for a seamless finish. Hand troweling is the application method professionals use.
Disadvantages of Trowels
However, using a trowel has some downsides:
Physical effort
Applying adhesive with a trowel takes more physical work as you have to kneel and spread it manually across the floor. This can be taxing on the knees and back.
Learning curve
Achieving an even, consistent spread takes practice. Newbies may end up with uneven adhesive depths across the floor.
Limited open time
Once adhesive is spread, you have a finite window to lay flooring before the adhesive dries. Working too slowly results in adhesion problems.
Difficult for beginners
First-timers may find gauging the right trowel notch size and adhesive depth challenging. Poor technique can cause hollow spots between the flooring and subfloor.
Small area coverage
Trowels are best suited for smaller installation jobs. Spreading adhesive by trowel over large areas is tedious and time-consuming.
Advantages of Using Liquid Flooring Glue
Glue adhesive offers its own set of benefits:
Easier application
Glue adhesive can be poured straight from the bottle before spreading across the floor with a trowel or roller. No need to manually trowel adhesive onto the floor.
Quick coverage
Pouring glue adhesive is faster for covering large subfloor areas compared to hand troweling. Just make sure to spread it evenly.
Beginner-friendly
Applying glue adhesive is easier for amateurs compared to gauging depth with a notched trowel. Just pour and spread.
Lower physical strain
No need for extensive kneeling and arm work to spread glue adhesive. This makes installation less demanding physically.
Extended open time
Glue adhesives typically have 60-90 minutes of open time versus 30-45 for trowel adhesives. More time to install flooring.
Can fill minor gaps
Glue adhesive has greater viscosity and “gap filling” properties. This can compensate for slight subfloor variations.
All-in-one application
Some glue adhesives allow adhesive to be poured directly onto the back of the engineered flooring planks as an all-in-one application.
Disadvantages of Using Glue
However, glue adhesive has some weaknesses to consider:
Less control
Pouring from a bottle allows less precision adhesive application compared to trowel notches controlling depth.
Lower adhesive bond
Glue adhesive does not create the same mechanical grip as the texture from a trowel notch. Bond strength may be reduced.
Hollow spots more likely
Due to less trowel ridges, glue adhesive has a higher chance of hollow spots between the flooring and subfloor.
Moisture protection lacking
Many liquid glue adhesives provide little moisture barrier. This makes the flooring more prone to moisture damage.
Messy overpour
It’s easy to accidentally pour too much glue adhesive, creating a runny messy application and adhesive drips.
Difficult stain cleanup
Excess glue adhesive that seeps into floor seams can be nearly impossible to clean up once dried. Trowel adhesive is easier to wipe up.
Less professional results
Without trowel notches controlling depth, amateurs are more likely to end up with uneven glue adhesion and messy results.
Trowel vs. Glue: How To Decide
Now that we’ve examined the pros and cons of trowel and glue adhesives, how do you decide which is best for your project? Here are some key factors to consider:
Your skill level
Beginners will find liquid glue easier while pros can achieve better results with a trowel.
Room size
For large rooms, glue adhesive will be faster and easier to apply over a trowel.
Subfloor material
On concrete, a moisture-blocking trowel adhesive is best. For plywood, glue adhesive works fine.
Flooring thickness
Thicker engineered flooring performs better with a trowel adhesive to prevent hollow spots.
Desired bond strength
Trowels form a tighter adhesive bond overall. Opt for glue if some gaps are acceptable.
Time constraints
Glue adhesive provides more working time, which is ideal for DIYers on tight schedules.
Cleanliness
Trowels make adhesive easier to wipe up. Glue leaves a mess if overpoured.
Cost differences
Glue adhesives tend to be slightly cheaper compared to using a trowelable product.
Recommended Trowel Adhesive Products
If going the trowel route, here are some top-rated adhesive products:
Bostik Best
- Notch options: 1/4″, 3/16″, 1/4″ x 1/4″, 3/16″ x 5/32″
- Non-slump for sloped floors
- Moisture barrier
Mapei Ultrabond ECO 980
- Low VOC formula
- Antimicrobial protection
- Excellent ridge hold
- 1/4″ x 3/16″ V-notch
DriTac 7700
- Extended 140 min working time
- Moisture resistant
- 1/4″ x 1/4″ square notch
Polymeric QS-240
- Quick 20 min setup time
- Sound-dampening
- 5/16″ V-notch
SikaBond T55
- Strong shear strength
- Goes on white, dries transparent
- 1/4″ x 1/4″ notch
Recommended Liquid Flooring Glue Options
For those opting for liquid glue adhesive, these products come highly rated:
Bostik Best
- No trowel needed
- Apply directly to flooring planks
- Wet lay installation
- Low VOC
Roberts 70-190
- 60 min open time
- Low odor
- Pourable formula
- Excess wipes up easily
Franklin 811 Plus
- 90 min working time
- Bonds well to multiple surfaces
- Contains antimicrobials
- Easy water cleanup
DAP WF-7781
- Application temperature range of 60°-95° F
- Does not require pre-sealing floors
- Waterproof adhesive
OSI F-565
- Non-flammable adhesive
- High strength formula
- Use with roller applicator
- Cleans with water when wet
