Slab moisture before a maple floor: what the published documents say

Documents read on 2026-10-04. Statements are attributed to the publisher and dated as printed.

This guide reports what published documents say about concrete slab moisture before a maple floor goes down. Each publisher's statements sit in their own section. Nothing here recommends a limit, a product or a maker.

Two data-sheet conflicts are printed in full, with both texts and their dates, and are marked unresolved.

MFMA

MFMA states, in Concrete Slab Moisture Content Testing (2025), Revised 12/25, accessed 2026-10-04: non-glue-down systems require slab internal RH of 85% or less, and glue-down systems 75% or less, with the ASTM F2170 in-situ probe as the primary confirmation method. The position statement lists calcium chloride at no more than 4.5 lb per 1,000 sq ft per 24 hours, says slabs should be at least 60 days old before testing, and says installation shall not begin until the slab is "dry" by F2170. It recognises only ASTM F2170 in-situ probe testing as its confirming method.

ASTM International

ASTM International states, in ASTM F1869-23 Standard Test Method for Measuring Moisture Vapor Emission Rate of Concrete Subfloor, F1869-23, active as of Sep 14, 2023 per the page, accessed 2026-10-04: the active edition, F1869-23, measures the moisture vapor emission rate of bare concrete subfloor using anhydrous calcium chloride, expressed in pounds per 1000 sq ft per 24 h. It excludes gypsum concrete, lightweight aggregate and coated or penetrant-treated concrete, and its results may not indicate future conditions.

Connor Sports

Connor Sports states, in VIP II specification, Section 09642, no printed revision, accessed 2026-10-04: the concrete is to be "determined dry by industry standard testing procedures".

Aacer Sports Flooring

Aacer Sports Flooring states, in SPECIFICATION: MULTISTAGE, Floating System (Section 09642), Revision Level A 2023, accessed 2026-10-04: the MultiStage specification requires in-slab relative humidity of 85% or less, measured with embedded probes, before subfloor components, with a 6 mil vapor barrier.

Robbins

Robbins states, in Robbins Bio-Channel Classic guide specification (hosted by Centaur Products), 7/25/2019 (as printed in the document header), accessed 2026-10-04: the Classic specification limits in-slab RH to 85% by ASTM F2170 and requires a 60-day concrete cure.

ARDEX

ARDEX states, in ARDEX MC RAPID Technical Data Sheet, content updated 2026-09-08, accessed 2026-10-04: MC RAPID is for concrete up to 100% RH (ASTM F2170), is rated at 0.06 perm (ASTM E96), and meets or exceeds ASTM F3010-18. The data sheet says it is not necessary to retest the substrate for moisture emissions before the next installation step: calcium chloride testing (ASTM F1869) is not a valid test method over a surface treated with a moisture control system, and ASTM F2170 testing requires drilling into the concrete.

ARDEX states, in ARDEX K 301 Technical Data Sheet, content updated 2026-09-21, accessed 2026-10-04: K 301 is not a vapor barrier; test RH per ASTM F2170 and use MC RAPID for moisture control.

ARDEX K 301: how soon the surface can be walked on (unresolved)

Two ARDEX data sheets for this product, each printing both statements, give different walk-on times. The texts stay exactly as published. This guide does not choose between them; the conflict is unresolved.

Data sheet content updated 2026-09-21, cover page: "Walk on in 2 to 3 hours." ARDEX K 301 data sheet, 2026-09-21, accessed 2026-10-04

Same data sheet, Step 6 dry-time table: Walkable: 24 hours (dry times stated at 70 F). ARDEX K 301 data sheet, 2026-09-21, accessed 2026-10-04

Earlier data sheet content updated 2023-10-11, page 1: "Walk on in 2 to 3 hours." ARDEX K 301 data sheet, 2023-10-11, accessed 2026-10-04

Same earlier data sheet, Step 6: "Walkable: 24 hours" for all other cases. ARDEX K 301 data sheet, 2023-10-11, accessed 2026-10-04

UZIN

UZIN states, in UZIN PE 460 Product Datasheet, month and year printed in the footer, accessed 2026-10-04: PE 460 is a two-component epoxy moisture vapor reduction product for concrete up to 100% RH, ASTM F3010 compliant, dry to foot traffic after 8 h at 68 F.

Sika

Sika states, in Sika MB product page, undated web page, accessed 2026-10-04: Sika lists Sika MB, a two-component epoxy, for a moisture vapor emission rate up to 25 lb, about 0.06 perm at one coat, and a cure time before SikaBond or SikaLevel products that varies with temperature, with about 8 hours listed at the middle of the three temperatures given.

PALLMANN

PALLMANN states, in PALLMANN P104 TURBO Product Data Sheet, footer 07/2025, accessed 2026-10-04: P104 TURBO is rated for one coat to 90% RH / 12 lb, two coats to 98% RH / 18 lb, and radiant heat to 85% RH / 6 lb.

PALLMANN P108 DEFEND: coverage per pail and abrasion before adhesive (unresolved)

The PALLMANN data sheet for this product prints statements that point in different directions on coverage and on when to abrade. The texts stay exactly as published. This guide does not choose between them; the conflict is unresolved.

Data sheet, coverage: "Maximum 200 sq. ft. per pail." PALLMANN P108 DEFEND data sheet, accessed 2026-10-04

Same data sheet, coverage when used as a moisture vapor retarder: Two coats at 200 sq ft per pail, per coat. PALLMANN P108 DEFEND data sheet, accessed 2026-10-04

Same data sheet, abrasion before adhesive: After 24-36 hours the surface must be abraded with 40 or 60 grit before a PALLMANN wood floor adhesive is applied. PALLMANN P108 DEFEND data sheet, accessed 2026-10-04

Same data sheet, a note on abrasion: For wood glued directly to P108: abrade (40 to 60 grit) after 48 hours from the last coat. PALLMANN P108 DEFEND data sheet, accessed 2026-10-04

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