---
title: "Subfloor Moisture for Glue-Down LVT | Flooring & Panels"
canonical: "https://flooringandpanels.com/insights/subfloor-moisture-glue-down-lvt/"
description: "Check subfloor moisture for glue-down LVT. Read % RH and CM% results, match them to your screed and verify your flooring and adhesive limits."
language: "en"
---

Flooring

# Is Your Subfloor Dry Enough for Glue-Down LVT?

Read your screed moisture report, match it to the flooring and adhesive instructions, and plan the next step before your glue-down LVT installation.

3 min read13 November 2026[By Flooring & Panels](https://flooringandpanels.com/our-expertise/)Updated 14 November 2026

In this article

Your glue-down LVT is booked for a shop fit-out. The screed report arrives with a percentage next to “moisture.” Before you release the installation, check how the reading was taken, which screed was tested and what limit applies to the flooring and adhesive you specified.

## Match your reading to the test method

A hygrometer test reports relative humidity in % RH. A calcium carbide test uses a sample of the screed and reports the result in CM%. Read each result against the limit for its own method. Ask your installer to record the screed type, the test method and the date, location and result of each measurement. Where the project includes underfloor heating, check the installation requirements for that setup too.

## Read two example reports against the flooring guide

These illustrative readings use Karndean’s November 2023 UK gluedown guide. Use the method specified for the job. [Karndean UK gluedown installation guide, November 2023](https://www.karndean.com/globalassets/karndean/downloads/residential-and-commercial/pdfs/installation-guides/uk/karndean-designflooring-installation-guidelines-uk-gluedown.pdf).

| What your report says | Limit in the example guide | What to do before installation |
| --- | --- | --- |
| 78% RH from the specified hygrometer test | Below 75% RH | Hold the installation. Confirm whether to allow further drying and retest or specify an approved moisture-control system. |
| 1.8 CM% on a cementitious screed from the specified carbide test | Up to 2 CM% on cementitious screed | The reading meets the flooring guide’s moisture limit for that screed. Check the adhesive and preparation requirements for the same build-up. |

For calcium sulphate screed, the same Karndean guide gives a separate carbide limit of 0.5 CM%. Record the screed type alongside the reading, especially when a project contains more than one substrate. Gerflor’s Creation installation guide also refers to the requirements of the country of installation. Check the documents for your destination market when you specify a range for several countries. [Gerflor Creation glue-down guide, 17 September 2024](https://media.gerflor.io/media/2/47532/%20%5B303%5D%20glue%20down%20installation%20creation%2030%20-%2040%20-%2055%20-%2070%20-%20installation%20guidelines.pdf).

## Approve your adhesive and preparation together

Ask for the technical sheet for your named adhesive as part of the quotation. For example, F. Ball’s Styccobond F46 data sheet specifies below 75% RH for a dry subfloor and calls for moisture treatment where needed. If your project requires a membrane, primer or smoothing compound, get the proposed combination confirmed for the screed, the adhesive and the LVT before work starts. [F. Ball Styccobond F46 technical sheet, April 2024](https://f-ball.com/wp-content/uploads/2023/10/F46_TechDataSheet_GB-1.pdf).

Add the project country, screed type, test report and proposed preparation products to your LVT brief. Agree who arranges any retest and who signs off the installation before the adhesive goes down. [Explore dryback LVT](https://flooringandpanels.com/lvt-flooring/dryback/), [Build your specification brief](https://flooringandpanels.com/specification-guide/).

Your next collection

## Specifying glue-down LVT for a project or a new collection?

[Build your glue-down LVT specification](https://flooringandpanels.com/specification-guide/)