June 2012 Rapid RH Newsletter – Announcing the New Rapid RH 4.0 EX
Announcing the NEW Rapid RH® 4.0 EX
The latest F2170 standard (ASTM F2170-11 www.astm.org/Standards/F2170.htm) calls for the RH test “sleeve” to fully line the entire test hole. Because 40% of slab depth can vary from job to job, the Rapid RH® 4.0 EX now uses a segmented “extension” insert that allows you to match the liner length to the test hole depth for complete compliance with the latest ASTM standard.
The new Rapid RH® 4.0 EX’s sensor design also has the advantage of working with thin topped slabs or shallow hole applications. It’s depth-selective design is one of the few RH test systems available that can still assure complete ASTM compliance.
External Influences on Internal Concrete Moisture Content
Concrete slab construction is an exercise in convergence. Builders apply several methods of facilitating the successful curing, drying and hydration of concrete slabs. However, those processes and building materials can distort moisture content readings. While this can be troublesome, contractors and consumers can help to avoid flooring failure by simply understanding the external forces that sway moisture content measurement.
A volume could be written on this topic, but let’s keep it simple: concrete slabs require sufficient time to dry and cure (two separate processes)…
From the Forum: RH in Concrete for Wood Floor with Vapor Membrane
I am looking for advise on establishing a RH for a wood floor system. (special system from Europe very dimensionally stable)
The flooring has a RH limit of 90% over 6-mil poly that has a perm of 0.06.
I want to put the flooring down over 15-mil poly with a perm of 0.018-0.01. (83% less)
What RH should the concrete be? perhaps 83% of the difference between 90 & 100? So that would be 98% RH? I don’t think it is a sliding linear scale though.