Rev.01.01.2015

Full-surface gluing with Stauf products OR Sika products only

For a successful result it is important to install the floor correctly and to use the products mentioned here in accordance with the instructions. We therefore recommend having a floor specialist install the floor. We also recommend that you carry out on-site tests to ensure that the products are appropriate for the purpose. We recommend that you follow the NWFA job site

requirements throughout the project.

Important conditions prior to installation

Building

  • The building must be dry and free of construction humidity in accordance with the NWFA Job Site conditions. Never have the floor planks delivered until the building is sealed, dry and warm, and the humidity levels are under control. If material is accepted on to a job site when the project is not 100% sealed and controlled, this cancels the warranty.
  • The temperature must be between 18 and 25 °C.
  • The air humidity must be between 35 and 65% RH and must not exceed 50% RH in winter. A hygrometer that records data should be in every room.
  • Ensure documentation of the moisture content in the subfloor, as concrete moisture may harm wooden flooring.
  • Concrete moisture must not exceed 85% RH, and a vapor barrier must be used. If you leave out the vapor barrier, the residual moisture content must be less than 65% RH. NB: 85% RH corresponds to approximately 2.0 CM depending on the type of concrete etc. Be aware of any restrictions in the national standard requirements and be sure to follow all NWFA requirements.
  • For the vapor barrier, use at least 0.20 mm PE foil or similar or Sika Primer MB.
  • The substructure must be straight with a maximum deviation of 2 mm, measured across a 2-metre straightedge.

Installation

  • Carry the planks inside immediately after delivery; do not leave them outside or in a garage under any circumstances.
  • Install the planks when the material has acclimated in accordance to the NWFA wood acclimation procedures. Planks should be placed in the room in which they are going to be installed for approximately 2-10 days prior to the installation. Time of acclimation depends on the environmental conditions.
  • Pay attention to color, knots and grain when you install the floor so the individual planks are placed in a way that produces an overall harmonious appearance.
  • Knock the floor planks closely together, unless future humidity conditions will cause the planks to absorb moisture (contact Monsterwide Plank for additional advice on this issue). Use a tapping block, approximately 1 meter, and a large, heavy hammer to drive the floor planks together.
  • Always leave a gap of 10-15 mm between the wood flooring and walls, pipes etc. Remove the spacer blocks once the floor is installed.
  • Never apply glue to the long sides of floor planks.
  • Always sand unfinished floors before finishing.
  • If the floor is not sanded and finished immediately after it is installed, cover it well. Keep the surface clean and free of nails, screws, wooden blocks etc. that might dent the floor.
  • Keep an eye on temperature and air humidity. If the planks are stored at an air humidity above 50% RH, they will absorb moisture and thus become wider. This will result in larger contraction gaps than normal.
  • Only use recommended products or products approved by Monsterwide Plank for surface finishing and maintenance as alternative products can cause unfortunate consequential damages.
  • If underfloor heating has been cast into the concrete layer, the underfloor heating must be turned on at an acceptable temperature for at least 30 days before the planks are installed.
  • Monsterwide Plank does not accept claims concerning the appearance of individual planks once the floor has been installed.
  • Monsterwide Plank does not accept claims concerning damage due to construction humidity.

Natural material

Wood is a natural material that expands and contracts continually, depending on the relative air humidity and temperature. If the indoor climate remains completely stable throughout the year, the planks will remain dimensionally stable, neither expanding nor contracting. That is, however, very difficult to achieve, even with expensive climate systems. Therefore, periodical contraction gaps should be accepted as the floor planks respond to the changing seasons. The movements of the planks will usually be most pronounced during the first year after installation. If the wood is unable to expand it will compress. The subsequent drying will then cause the plank to contract beyond the initial dimension. This may result in slightly larger contraction gaps between the planks than initially. Our material is the most highly sophisticated and most stable wide plank flooring in the world. 70% more stable than solid material. However, this does not mean the material will not move it can and it will because it cause it still is wood. This also does not mean one can cut corners during the acclimation and installation process.

Below is an overview of the reaction of the floor planks to varying degrees of air humidity at a normal temperature of 18-25 °C.

The overview applies to a correctly installed floor, cf. the guidelines in this and the other instructions from Monsterwide Plank, and the information is only intended as a general guide.

Climate condition Reaction
60-70 % RH Slight transverse warping should be expected
50-60 % RH No contraction gaps, slight warping should be expected
40-50 % RH The floor planks are stable and level
30-40 % RH Moderate contraction gaps (approximately 1% of plank width) and slight warping should be expected
20-30 % RH Contraction gaps of 1% of the width or more and moderate transverse warping should be expected. There will also be minor drying cracks
< 20 % RH More pronounced transverse warping and drying cracks will appear. The floor will be depleted, and the lifetime of the planks will be reduced

The Installation

Before the floor is installed, make sure that the general conditions in the building are under control and in accordance with The NWFA and adhesive manufacturer. If there is ever a conflict between the two, it is your responsibility to contact and resolve the conflict.
The air humidity must be between 35 and 65% RH and must not exceed 50% RH in winter. The temperature must be between 18 and 25° C.
The substructure must be straight with a maximum deviation of 2 mm measured across a 2-metre straightedge.
For all substructures, Monsterwide Plank’s recommendations about humidity apply.

For cast substructures:

  • Moisture content must not exceed 85% RH. NB: 85% RH corresponds to approximately 2.0 CM depending on the type of concrete etc. Be aware of any restrictions in the national standard requirements and in accordance to the NWFA.
  • We recommend using STAUF VPU-155 S primer
  • We recommend using Sika MB-Primer

For anhydrite substructures:

  • Moisture content must not exceed 65% RH
  • Do not use STAUF VPU-155 S primer or Sika MB Primer
  • Contact Stauf or Sika for further advice

For plywood and chipboard substructures:

  • Make sure that the sheet/board and its surface is suitable for the purpose and a minimum ¾” thick
  • Moisture content must not exceed 8-10%. In addition, follow the NWFA’s general requirements for humidity and climate
  • Check that the glue bonds correctly to the surface
  • Contact Stauf or Sika for further advice
  • Always full spread

Other substructures:

  • Contact Stauf or Sika for further advice

If underfloor heating has been cast into the concrete layer, the underfloor heating must be turned on at an acceptable temperature for at least 30 days before the planks are installed. With underfloor heating, make sure to turn the heat off at least 24 hours before gluing. Do not turn on the heat until 7 days after the floor has been glued. Turn up the heat slowly, following always follow the NWFA’s before installation instructions.
Use STAUF VPU-155 S primer and STAUF PUK 455 glue or use Sika MB-Primer and Sika Bond T-55. Follow manufacturer’s and Europa Woods’s instructions carefully with regard to:

  • Climate conditions
  • Grade, evenness and moisture content of the substructure
  • Use of tools
  • Drying times for filler, primer, mastic etc.
  • Mounting and curing times for primer and glue

In addition, always follow Monsterwide Plank’s instructions generally.

1.1.1 Approval of substructure
Before installing the floor, check that the cast substructure lives up to the relevant guidelines. The substructure must be resistant to pressure and tension, free of cracks, have sufficient surface strength and be permanently dry, level, clean and free of anti-adherents, sinter layers etc.
Also check the porosity and grip of the surface as well as the moisture content, room temperature, air humidity and substructure temperature. The substructure must be permanently dry. Floors with residual moisture (max. 85% RH) require a vapor barrier. To create a vapor barrier, use STAUF VPU-155 S primer or Sika MB Primer.

  • Note that the drying process is slow. It can take several months before the substructure is dry enough. We strongly recommend that you perform a destructive test of the cast substructure to check the residual moisture content before applying the recommended primer. If you are using measuring methods and units for residual moisture content that deviate from national traditions and standards, contact Stauf, Sika or Monsterwide Plank for thorough information. Concrete moisture can and will harm the wooden floor.

1.1.2 Preparation of substructure
Before installing the floor, it is necessary to prepare the substructure. The surface must be clean, have sufficient surface strength and be level, permanently dry and free of cracks. Depending on the type and condition of the substructure, it may be necessary to prepare the substructure by mechanical means (mechanical brushing, sanding, levelling).
Construction joints, expansion joints and other joints must be closed with appropriate elastic material. Cavities and dents can be filled with appropriate levelling compound from Stauf. Contact Stauf for further advice.

1.1.3 Application of STAUF VPU-155 S primer or Sika MB Primer
To create a vapour barrier with the primer, carry out the following process:

  1. Apply 150 g/m² primer as a first coat with a mohair roller. Make sure to apply the primer evenly, and avoid large concentrations in one place. Alternatively, you may use a foam roller, a brush or a smooth blade.
  2. Allow the primer to dry for at least 45 minutes.
  3. Apply 250 g/m² using the same procedure but moving perpendicular to the direction of the first layer.
  4. Allow the primer to dry for at least 3 hours before installing Monsterwide Plank’s planks.
  5. Check and approve the surface before installing the planks.
  6. Always consult with manufacturer to confirm proper application procedures for these may have changed.
  • Note that the drying times stated below apply when air humidity and temperature stay within 40 and 50% RH and 18 and 22 ºC.

The planks must be installed within 48 hours after the application of the primer. If this timeframe is exceeded, sand the surface thoroughly, and apply a new, thin layer of STAUF VPU-155 S primer or Sika MB Primer, using 100 g/m².

1.1.4 Application of STAUF PUK 455 glue or Sika T-55 glue
After preparing the substructure and applying the primer, apply STAUF PUK 455 or Sika T-55 glue with their recommended notched trowel. Follow manufacturers cover rate per pale and use their recommended trowel.

Make sure to apply enough glue for the planks to bond fully with the substructure. This takes 1400-1600 g/m². The glue is fully cured after 48 hours.
Rake the notched trowel evenly over the adhesive layer to avoid large concentrations of glue in one place or too thick layers. Install the planks within the primer’s timeframe by sliding the planks in and pressing down firmly. Pay attention to the mounting time of the glue.

General installation

Install the planks immediately, except in winter when the planks should be placed in the room in which they are going to be installed for 24-48 hours prior to the installation.
Do not combine full-surface gluing with other installation methods. Only glue the planks themselves to the substructure.

  • Never apply glue to the long sides of floor planks!

It is recommended to use temporary fixing straps to keep the joints tight and hold the planks in place while the glue cures. Make sure not to damage the edges of the planks when applying the straps. To ensure a straight line for the rest of the floor, it is recommended that you install 3-4 rows, allow the glue to dry and then install the rest of the floor.
Apply weights on the planks during the curing period to ensure sufficient pressure across the entire floor. Place 15 kg sand bags, buckets with sand or similar weights on top of the planks. Distribute them evenly with approximately one load per m2 until the glue has cured. The areas along the edges of the floor and the last installed rows are particularly important. The floor should not be used until the glue has cured.
Sanding and finishing should not be performed until at least 48 hours after the full-surface gluing.

1.4 Advice
A Monsterwide Plank floor is a unique piece of nature. It is a living material which should be treated with care. Our instructions explain in detail how you get the best result so the floor can last for centuries.
These instructions cannot stand alone. For additional information, we refer you to the general instructions from Monsterwide Plank and Stauf. If you need additional advice about Monsterwide Plank floors, you are very welcome to contact us. To order and purchase products for maintenance, please go to www.MonsterWidePlank.com.
Please note that we can only offer advice about our own product, and thus, any additional advice lies outside the service we offer. Other building components and products require a degree of knowledge and insight that makes it necessary to seek advice from a specialist. As we have no control over the actual quality of workmanship, materials used and worksite conditions, these written instructions do not constitute an implied warranty of any kind.

Contact Information: Monsterwide Plank USA 888-995-7662 Stauf Adhesives Sika Adhesive NWFA NWFA Certified Installer