Trade notes
The things that
cost money twice.
Short technical notes from the trade desk, written for the person specifying or fitting the material. Every figure here is checkable against a product page on this site.
Measure the wall, not the door
Nine door problems out of ten are a casing problem. Here is what to record before the order goes in, and why the answer arrives three weeks later than you think. 8 September 2026
Concrete, clay or steel: what the roof actually decides
The covering is chosen on appearance and then constrained by three numbers — dead load, minimum pitch and what is on the ladder. 26 August 2026
AC4 or AC5: what the wear class is actually telling you
The number on the pack is an abrasion test, not a durability rating. Here is what it predicts, what it does not, and where the money is better spent. 12 August 2026
WT 2021 in millimetres: what the U-values mean on site
The regulation is written in W/m²K. Nobody orders in W/m²K. These are the depths that actually get you there, per material. 24 July 2026
Above 60 × 60, everything changes
Large-format porcelain fails in ways small tile does not. Adhesive class, substrate tolerance and handling are the three that cost money. 30 June 2026
Getting a partition to 47 dB without doubling the stud
Acoustic performance in drywall is mostly about mass, decoupling and sealing. Two of the three cost almost nothing. 5 June 2026
Why tile from two pallets does not match
Calibre and shade are printed on every box and read by almost nobody. They are the single most common cause of a re-tile. 18 May 2026
Sequencing an ETICS façade in one season
Render systems are weather-dependent at four separate stages. Getting the order right is what keeps a façade off the following spring. 22 April 2026Got a detail you are not sure about?
Send the drawing or the section. We will tell you what the build-up needs and price it — whether or not it turns into an order.