The right timber flooring adhesive holds boards to the subfloor for years while the timber expands and contracts with the seasons. The best choice depends on the type of flooring, the subfloor, moisture levels, and whether the floor sits over underfloor heating.
This guide covers what to check before you buy. It uses two products from the Glue Guru timber flooring range as examples: Quilosa BH-210 MS Flooring Adhesive and Selleys Liquid Nails TimberFlex.
Why the Right Adhesive Matters
Timber expands and contracts as temperature and humidity change. If the adhesive is too rigid or does not suit the subfloor, the floor can develop hollow spots, lifting, or gaps between boards.
A good timber flooring adhesive should:
● Bond firmly to both the boards and the subfloor
● Stay flexible enough to allow for timber movement
● Suit the moisture conditions in the room
● Keep hollow spots to a minimum
● Be suitable for underfloor heating if the floor is heated
Choose a product made for timber flooring instead of a general-purpose construction adhesive, and check the flooring manufacturer's recommendations before you buy.
Match the Adhesive to the Type of Flooring
Solid Timber Flooring
Solid timber expands and contracts with moisture, so the adhesive needs to stay flexible. Consider the timber species, board width and thickness, installation method and subfloor. Selleys TimberFlex is listed for most types of solid, engineered strip and sheet timber flooring over concrete and timber.
Engineered Timber Flooring
Engineered boards have their own installation requirements, so follow the manufacturer's recommended method and adhesive type. Selleys TimberFlex is also listed for engineered overlay flooring, including prefinished and bamboo.
Parquet and Pre-Finished Flooring
Parquet and pre-finished boards often have surface finishes that need care during installation. Quilosa BH-210 is recommended for natural and pre-finished parquet. Its listed uses include overlay strip, parquetry, laminated parquet, lacquered parquet and exotic timbers such as teak and bamboo.
Check the Subfloor
The adhesive has to suit both the flooring and the surface beneath it. Common subfloors include concrete, plywood, particle board and existing timber flooring. Quilosa BH-210 lists concrete, timber, plywood, particle board, battens and stone. Selleys TimberFlex lists plywood, particle board, existing strip flooring, fibre cement sheets, concrete and acoustic matting.
Prepare the surface before you start. The subfloor should be:
● Clean
● Dry
● Level
● Structurally sound
● Free from dust, grease and other contaminants
Allow for Timber Movement
Indoor temperature and humidity change through the year, and timber expands and contracts with them. A flexible adhesive allows for slight movement without breaking the bond. Quilosa BH-210 is described as highly elastic and as resisting rafting and cupping. Selleys TimberFlex is a flexible, trowel-grade adhesive with good ridge formation, stability, wet grab and initial hold.
Consider Moisture
Excess moisture in the subfloor or the timber can affect the floor and the bond. Before installing:
● Check moisture levels in the slab or subfloor where required
● Let the flooring acclimatise as the manufacturer directs
● Choose an adhesive suited to the conditions in the room
Quilosa BH-210 is described as moisture- and heat-resistant and ideal for moisture-sensitive timbers. Any moisture problem in the subfloor still needs to be fixed before laying, whichever adhesive you use.
Underfloor Heating
Heating adds temperature changes to both the floor and the adhesive, and not every product is approved for heated floors. Check the manufacturer's data sheet before you buy. Quilosa BH-210 is listed as suitable for underfloor heating. If you are considering another product, confirm its suitability with the flooring manufacturer and the adhesive supplier first.
Timber Flooring Adhesives at Glue Guru
The Glue Guru timber flooring collection includes the following products.
Quilosa BH-210 MS Flooring Adhesive (15 kg)
Quilosa BH-210 is a single-component MS flooring adhesive for parquet, pre-finished and overlay strip flooring. Glue Guru is the New Zealand and Australian agent for Quilosa. BH-210 is solvent-free, low odour, and low VOC, with high bond strength, and it is designed to minimise hollow spots. Coverage is approximately 15 m² per 15 kg pail, with full cure in 72 hours. Clean up with water while the adhesive is wet, or with acetone.
Selleys TimberFlex (10 L Pail and 600 mL Sausage)
Selleys TimberFlex is a flexible, trowel-grade adhesive for solid, engineered strip and sheet timber flooring over concrete and timber, available as a 10 L pail or a 600 mL sausage. It uses an advanced polymer formulation that is isocyanate-free and solvent-free, and its low VOC content meets Green Building Council requirements. It spreads at temperatures from 5°C to 40°C and is easy to remove from prefinished boards, tools, and hands.
Coverage on a plywood substrate with a Direct Stick trowel is 20 m² per 10 L pail or 1.2 m² per 600 mL sausage.
Application, Coverage and Curing
Check the product data sheet before you buy so you can plan the job. Look for:
● Coverage per pack and the trowel size it is based on
● Open time and working time
● Curing time
● The temperature range for application
● The recommended clean-up method
Measure the floor area first and allow extra for uneven subfloors, because coverage figures are based on a specific trowel and substrate.
Low VOC and Low Odour
Low VOC and low odour adhesives suit occupied homes, offices and enclosed rooms. Both Quilosa BH-210 and Selleys TimberFlex are solvent-free and low VOC. Check the VOC content and ventilation requirements on any product you are comparing.
Common Mistakes to Avoid
Using a general-purpose adhesive. Choose a product made for timber flooring and suited to your flooring type.
Ignoring the subfloor. Dust, grease, and uneven surfaces weaken the bond, so prepare the surface fully.
Overlooking moisture. Test for it and fix any problem before laying.
Forgetting underfloor heating. Confirm that both the flooring and the adhesive are suitable for heated floors.
Skipping the instructions. Follow the manufacturer's directions for surface preparation, application, and curing.
Conclusion
The right adhesive suits the flooring type, the subfloor, the moisture conditions, and any underfloor heating, and the floor should be laid following the flooring manufacturer's instructions. Quilosa BH-210 and Selleys TimberFlex are two options from the Glue Guru timber flooring range, and each product page lists its uses and coverage.
Browse the full timber flooring collection, or contact the Glue Guru team with your flooring type and subfloor for advice on the right product.