Installing Wood Flooring Using Adhesive

Many solid and engineered floors can be laid using wood flooring adhesive.. There are two main techniques for installing using adhesive, which will both be explained. Please remember that solid floors should always be glued down, not using the floating method.

Floating Floor Method

Gluing the tongues and grooves of the floor together does the floating floor method of fixing the wooden floor. This creates a new floor, which is “floating” over the original floor. Engineered floors can be floated over any solid sub floor and it is the preferred method for laying engineered floors.

It is a good option when the sub floor moisture content is unknown, because a damp proof membrane can be used between the floor and sub-floor to prevent moisture rising into the new flooring. When floating a floor, an underlay must be used to cancel the effect of any echo and also provide a leveling effect to the sub-floor.

This echo is caused by the two hard surfaces together which have a space between them. The noise echoes in this void. The purpose of underlay is to prevent any echo, as the two hard surfaces will not be adjacent with each other. The choice of underlay is huge for use when floating the floor all of which are adequate.

A good quality underlay is advised, as this ensures there is less sound echo from foot traffic. Generally the denser an underlay the less noise!

To float the floor:

Lay out the damp screen ensuring that the edges of the membrane continue up the side of the skirting. And overlap the seams by 100mm Lay out the underlay ensuring all areas of the floor are covered. Any areas left uncovered with the underlay will cause a bounce in the new floor and will be noisier.

A D3 rated PVA wood adhesive is used to glue the boards together.

Fit the floor by placing two beads of adhesive along the upper and lower sides of the “groove” joint. (It is a common mistake to think that the boards need to be glued along the “tongue” – this will simply push the adhesive too far into the joint and not create a firm bond between the boards.). Glue the complete length of the board all the way down the planks as this prevents the board from creaking.

Leave the joints and glue to dry before walking on the floor. Any PVA glue, which has spilled or oozed onto the boards can easily be wiped off a lacquered or oiled board, or sanded off an unfinished floor. It must be noted that thermo treated solid oak has less density therefore water based pva will not adhere to the timber as well as normal oak.

The Glue Down Method

The glue down method of fitting a floor consists of using a specified adhesive applied directly to the sub-floor such as F Ball B92 enabling the new floor to stick directly to the original floor. This is a very stable method, which is the recommended option for most solid wood and parquet floors.

To install wood flooring using an adhesive, you must first ensure that the sub-floor is dry, level and structurally sound.

When laying onto concrete it is best to prime the area first using a PVA based primer to ensure a good bond to the floor. Old concrete should be checked for moisture and or contamination before the boards are laid. Both engineered flooring and solid flooring can be laid using the glue down method.

Installing:

The first thing to do is ensure the sub-floor is completely flat, free from dust and dirt and if necessary has been primed. in a satisfactory condition (see above) Working in an area just large enough to complete within 30 minutes, apply the adhesive to the sub-floor using a trowel with the specified notch size ensuring the whole sub-floor surface has an even amount of glue.

Install the new floorboards ensuring all boards have been pulled tight and have not been moved out of place as other boards have been fitted. It may be advisable to clamp up any slightly bent boards at this stage.
Leave the adhesive to cure for 12 hours and do not walk on the floor until it is fully set.

Unlike PVA adhesive, flooring adhesive is very difficult to remove from the surface of the boards. Ensure that any spills on the boards are wiped off immediately before the boards have dried.

Other Adhesive based fitting methods:

The are other adhesive based fitting options used to fit flooring:

Adhesive backed underlay. The underlay has a sticky side covered in a plastic film, which is peeled back as the floor is laid. Envoy multi, Elastilon and Acoustalay adhesive 300/1000 are all types of adhesive backed underlay.
Precautions

It is imperative that wood is given adequate chance to acclimatize before being bonded to the sub-floor. Allow at least two weeks for a solid wood floor and 48 hours for an engineered wood floor.

Take a thorough moisture check of the sub- floor for latent or rising damp. If in any doubt an application of an epoxy resin damp screen is advised