Floor Prep Guide

Acclimation

Other names for this test: conditioning, jobsite conditioning, letting the flooring adjust to the room.

What the test measures

Acclimation is the time and the conditions that bring new flooring into step with the room it goes into. There is no single reading; the record is of the room’s temperature and humidity, and for a wood floor of the moisture in the flooring and the subfloor. NWFA’s installation guidelines put the aim this way:

When the wood flooring is delivered at a MC that coincides with the expected in-use (e.g., normal living) and manufacturer’s required ambient conditions within the facility, and this coincides with the subfloor moisture conditions, and these conditions are being maintained, the flooring may be installed immediately.

NWFA Installation Guidelines, Revised © 2025, p. 34 (PDF p. 38)1

The criterion in NWFA’s words is a match of conditions, not a number of days. Manufacturers’ documents set their own conditions, and the table under Red flags shows how far they differ. For the wood moisture readings themselves, see Wood subfloor moisture.

What a valid report looks like

A complete record names, at minimum:

  • the date the flooring was delivered and the date installation started;
  • where the flooring was kept, opened or unopened;
  • the air temperature and relative humidity in each room, before delivery, on delivery and at installation;
  • since when the heating and cooling had been running;
  • for a wood floor, the moisture readings of the flooring and the subfloor;
  • the product document the conditions were compared with.

NWFA’s installation guidelines also set out what is checked and when. Where a record says what was checked, these are the points to hold it against, quoted from NWFA:

Before delivery
“Prior to delivery of the wood flooring, check and record the jobsite ambient conditions and the subfloor moisture to ensure they coincide with the wood flooring requirements that have been selected.”1
On delivery
“Upon delivery of the flooring to the jobsite, recheck and record the temperature and relative humidity in the space receiving the wood floor.”1
In each room
“Test and document the temperature and relative humidity in each of the room(s) where flooring is being installed.”1
Before, during and after
“These same conditions should be maintained prior to, during, and after wood flooring installation.”1
At installation
“It is the responsibility of the Installer to recheck the jobsite conditions at the time of installation and to confirm that they meet or exceed the wood flooring manufacturer’s requirements.”1

This is NWFA’s procedure, not the floor document’s; where your product’s document describes acclimation, that document applies.

Red flags

Acclimation: published limits by floor type, from manufacturers’ documents.
Floor type Published limits Documents Conditions
Rigid core vinyl not needed if HVAC is running and the material is within 15°F of the room at least 48 h in the room at 55-85°F best practice: 48 h at a constant 55-90°F before and during installation if exposed below 40°F, above 95°F, or below 35% / above 70% RH: unopened cartons, unstacked, in the room for at least 12 h 4 documents 2 3 4 5 HVAC running; storage within 15°F of the room 2 best practice, when acclimation is done 2 flooring exposed outside 40-95°F or 35-70% RH 4 5
Glue-down LVT at least 24 h, out of the packaging, in the room 48 h at 65-85°F before and during installation not required if the product is between 30 and 120°F flooring and adhesive in the room at least 24 h before installation 48 h if stored outside 65-85°F at least 48 h, cartons spread out, if exposed below 30°F or above 120°F for over an hour flooring material and adhesive at least 48 hours in the installation area 5 documents 6 7 8 9 10 with K-99HM adhesive 7 flooring and adhesive stored outside 65-85°F 7 flooring exposed outside 30-120°F for more than one hour 9 repeated under 5. Installing Resilient Tile & Plank 10
Laminate at least 48 h, unopened cartons flat in the room may be skipped if storage and room differ by no more than 25°F and 20% RH at least 48 h, boxes flat in the room unopened, lying flat, in the room at least 48 h 96 h (4 days) 4 documents 11 12 13 14 no time for acclimation 11 13 wall installation 13 very dry or very humid climates 12
Engineered hardwood moisture equilibrium at normal living conditions (30-55% RH, 60-80°F) unopened boxes 24-48 h in the room cartons conditioned at least 24 h before installation 2 documents 15 16 electric radiant heat 15 severe temperature or humidity difference 16
Solid hardwood Only one company publishes a limit for this floor type in the documents read, so no range is shown. Its limit is quoted under the table.

The limit that binds you is in your product's installation document.

Solid hardwood: the one company’s limit, from Mirage Installation Guide, Solid Prefinished Hardwood Floors (Mirage Classic).

Keep boxes of wood in room where flooring is to be installed for at least 24 hours before installation.

Mirage Installation Guide, Solid Prefinished Hardwood Floors (Mirage Classic), PDF p. 417

  1. Any floor type: the record gives a number of days and nothing else. A day count says nothing about the room the flooring sat in. The documents read do not agree on one either: in rigid core vinyl alone, 4 documents give 4 different conditions, listed in the table.

  2. Any floor type: the heating and cooling were not running before delivery. NWFA:

    These systems should be operating for a minimum of 5 days preceding delivery of flooring materials.

    NWFA Installation Guidelines, Revised © 2025, p. 32 (PDF p. 36)1

  3. Any floor type: no temperature or humidity was recorded. Without them there is nothing to compare with the product’s conditions; NWFA’s checks are under What a valid report looks like.

  4. Factory-finished wood: the record follows a general rule instead of the product’s document. NWFA:

    For factory-finished solid and engineered wood flooring, always follow the manufacturer’s requirements for interior temperature and relative humidity requirements.

    NWFA Installation Guidelines, Revised © 2025, p. 32 (PDF p. 36)1

    The limit that binds you is in your product's installation document.

Questions to ask the installer

  1. Which product’s installation document did you follow for acclimation, and what does it ask for?
  2. When was the flooring delivered, and where was it kept until installation?
  3. Since when have the heating and cooling been running?
  4. What were the temperature and humidity in each room on delivery and at installation?
  5. For a wood floor: what did the flooring and the subfloor read before installation?
References (17)

References

  1. 1 NWFA Installation Guidelines. NWFA. Revised © 2025. https://nwfa.org/wp-content/uploads/2026/02/NWFA-Installation-Guidelines.pdf. Read . ↩a↩b↩c↩d↩e↩f↩g↩h
  2. 2 Mannington ADURA Max Install Guide. Mannington. rev. 05.16.2024. https://assets.ctfassets.net/r69d9lchftro/qCw4Uqxa3cq2fI1bKVby9/76c789d4ccc805eb4069ffb98068d7b4/ADURA_Max_InstallGuide2024_01F.pdf. Read . ↩a↩b↩c
  3. 3 Mohawk SolidTech Installation. Mohawk. Rev. October 2018. https://mohawk.blob.core.windows.net/mohawkflooring/pdf/install/SolidTech_Installation.pdf. Read . ↩
  4. 4 MSI Everlife Rigid Core flyer. MSI. https://cdn.msisurfaces.com/files/flyers/rigid-core-everlife-lvt-flyer.pdf. Read . ↩a↩b
  5. 5 MSI Hybrid Rigid Core Installation Guide. MSI. https://cdn.msisurfaces.com/files/flyers/hybrid-rigid-core-installation-guide.pdf. Read . ↩a↩b
  6. 6 Karndean Gluedown Installation Guideline USA. Karndean. KD80333GLO | October 2023. https://karndeancommercial.com/globalassets/karndean/b2c-blocks/b2c-document-listing-block/usa/installation-guides/karndean-gluedown-installation-guideline-usa.pdf. Read . ↩
  7. 7 Karndean K-99HM Adhesive Installation Guide. Karndean. 240902. https://www.karndeancommercial.com/globalassets/karndean-commercial/blocks/b2b-brochure-listing-block/usa/install-guides/us-karndean-k99-hm-adhesive-installation-guide-240902.pdf. Read . ↩a↩b↩c
  8. 8 Mannington ADURA Flex Installation Instructions. Mannington. Copyright © 2026. https://assets.ctfassets.net/r69d9lchftro/72wp40QH7Sjze2rfjb2mBs/eda3a968f13c3aebe68000069be092bd/ADURAFlex_Installation_Instructions_2026.pdf. Read . ↩
  9. 9 MSI Everlife Acclima Glue-Down Installation. MSI. https://cdn.msisurfaces.com/files/flyers/acclima-gluedown-installation.pdf. Read . ↩a↩b
  10. 10 Shaw Resilient Residential Installation Guidelines, glue-down. Shaw. Revision: 04012022. https://pdmsview.shawinc.com/Shaw-Residential/Shaw-Residential-Installation/Resilient-Installation/Glue-Down/Resilient-Residential-Installation-Guidelines. Read . ↩a↩b
  11. 11 Mohawk RevWood Plus Installation Instructions. Mohawk. https://mohawk.blob.core.windows.net/mohawkflooring/pdf/install/Revwood_Plus_Installation_Instructions.pdf. Read . ↩a↩b
  12. 12 Pergo Installation Essentials Guide (Mohawk). Pergo (Mohawk). https://mohawk.blob.core.windows.net/pergo/pdfs/Installation_Essentials_Guide_Combined.pdf. Read . ↩a↩b
  13. 13 Quick-Step Studio installation (Unilin). Quick-Step (Unilin). Edition Date: 04/01/2020. https://pdf.lowes.com/installationguides/604743166056_install.pdf. Read . ↩a↩b↩c
  14. 14 Swiss Krono USA installation FAQ. Swiss Krono. https://www.swisskrono.com/us-en/faq/installation/. Read . ↩
  15. 15 Hallmark Engineered Wood Installation. Hallmark. 05-2026. https://hallmarkfloors.com/pdfs/Installation-Instructions-Eng-Wood-WEB.pdf. Read . ↩a↩b
  16. 16 Mannington Hardwood Install Guide. Mannington. Copyright © 2025. https://assets.ctfassets.net/r69d9lchftro/1z2pM4YyPCtbRibzxxpYEu/1898b6f3500c462b163ada0fa0d68865/Hardwood_InstallGuide2025_02.pdf. Read . ↩a↩b
  17. 17 Mirage Installation Guide, Solid Prefinished Hardwood Floors (Mirage Classic). Mirage. https://media.planchersmirage.com/webfolder_download/ea857cc59594ba5743ea8f81d0bb81d1/file/2d7a6951401a1af90be5f366c1f36ca448debdab/file.pdf. Read . ↩