MC024-7.7 Interstitial Condensation in Facades: The Glaser Method
From Layer Stack to a Defensible Report — A Complete Practical Framework for Interstitial Condensation (Glaser Method) Analysis
Join Live Seminar - 21 January 2027 - Free to attend live
Join us for a hands-on technical CPD on interstitial condensation and the Glaser method. This session takes one real wall — a light-steel-frame construction with a brick-slip rainscreen — and builds the complete moisture calculation chain from scratch: from defining the assembly to a report you can hand to a client and defend.
Presented by Eugene Korch (IAST), this seminarfollows the same wall from a clean failure — no working vapour-control layer — through to a verified pass, and is honest about the silent errors that make a condensation report wrong while it still looks completely right.
This course covers:
Why condensation forms inside walls — the difference between surface and interstitial condensation, and why a steady-state check is the right first tool for finding hidden moisture before it forms on site
Defining the assembly — why every layer counts for moisture, including the thin membranes a heat-loss calculation safely ignores
Vapour diffusion properties — the vapour resistance factor and the equivalent air-layer thickness that puts every material on one comparable scale
Building the layer stack — inside-to-out order in the programme, the single most common data-entry error, and how to handle steel studs and a ventilated cavity
Boundary conditions and climate data — twelve months of temperature and humidity, the element-type setting, the humidity class, and the return-period adjustment
Running the analysis and reading the moisture table — checking both the surface and interstitial results, and the pass/fail rule: drying must be at least equal to build-up
Reading the Glaser diagram — the saturation curve, the actual vapour pressure line, the safety margin, and the exact condensing interface
Fixing the failing assembly — three genuine routes to a pass, and the engineering trade-offs between them
Reporting and common errors — what a defensible report must contain, and the invisible mistakes that hide in plain sight
Using one real worked example from start to finish, this CPD focuses on practical judgement — not just how to get a number, but how to know when to trust it.
What You'll Learn
Distinguish interstitial condensation from surface condensation, and explain why a steady-state Glaser check is the right first tool for finding hidden moisture on the drawing before it forms on site
List every layer of a real wall build-up for a moisture calculation, including the thin membranes and control layers that are safely ignored in a heat-loss calculation
Source and select vapour resistance factor values correctly, choosing the conservative end of a material’s range rather than the value that flatters the result
Build a layer stack correctly inside a thermal modelling programme, in true inside-to-out order, entering thicknesses in metres and catching the single most common data-entry error
Handle the two special cases every real wall presents: a mixed stud-and-insulation layer treated as a uniform equivalent for moisture, and a ventilated cavity that ends the calculation before the outer cladding
Set up twelve months of climate data correctly, including the element-type setting, the humidity class, and the return-period adjustment — and know when that adjustment reverses in a warm or dry climate
Run a condensation-risk calculation from an existing heat-loss model without rebuilding it, and read both the surface and interstitial results before trusting either one
Read a moisture table and a Glaser diagram to identify the exact condensing interface, the size of the safety margin, and whether a wall dries out fully every summer
Apply the pass/fail rule correctly: that a wall may get damp in winter, but must dry out at least as much as it wets up, checked across both seasons
Choose and apply the right fix for a failing assembly — a vapour-control layer, a more vapour-open board, or added insulation — and understand the engineering trade-offs between them
Read a thermal modelling programme’s own condensation report critically, and assemble a complete, reproducible report of your own with every source, climate setting, and diagram it requires
Recognise the most common invisible errors in interstitial condensation work — a library default left unchanged, the wrong element type, an optimistic material value, a membrane on the wrong side, and a bracket cold spot the method cannot see
Recognise the genuine limits of the steady-state Glaser method, and know when a result is marginal enough to call for dynamic hygrothermal simulation instead
Target Audience
This session is designed for design professionals who need to build, run, or review an interstitial condensation calculation for a real project — particularly those working with modern multi-layer wall build-ups where hidden moisture risk is easy to miss.
This Short Course is designed for:
Architects
Architectural Technologists
Envelope Designers
Façade Specialist Contractors
Façade Engineers
Junior Façade Engineers
Building Envelope Consultants
Building Physics Consultants
Project Managers
Design Managers
Speaker
Eugene Korch
Programme Director, IASTEugene is a facade engineer and educator who leads educational initiatives through the Institute for Architectural Science and Technology (IAST) and Facade Intelligence, delivering training to construction professionals.
Course Details
Format: Live online seminar with interactive polls and a live model walkthrough
Duration: 60 minutes + Q&A
Date: 21.01.2027
CPD Points: 2 hours structured CPD / 2 Learning Units
Certificate: CPD certificate provided upon completion
Recording: Available on demand to members only
MC024-7.7
Interstitial Condensation in Facades: The Glaser Method
From Layer Stack to a Defensible Report — A Complete Practical Framework for Interstitial Condensation (Glaser Method) Analysis
Course Fee £120
Free for FI Pro Members
