Building Materials & Insulation Glossary Terms

What Does U-Value Mean for Insulation?

U-value measures how much heat passes through a material or structure — the lower the number, the better the insulation performance. It is the opposite of R-value (used more in the US), where a higher figure is better, so UK insulation products are typically compared by looking for the lowest U-value that fits the required building regulation for that part of a home.

What Is a Damp Proof Course (DPC)?

A damp proof course is a barrier — traditionally a physical membrane, or chemically injected in older properties — built into a wall near ground level to stop rising damp from soil moisture travelling up through masonry. UK building regulations require a DPC in new construction, and a failed or bridged DPC (for example by external ground level built up too high against a wall) is a common cause of damp problems in older homes.

What is Galvanised Steel?

Galvanised steel is a type of steel that has been coated with a layer of zinc to protect it from rust and corrosion. This coating significantly increases its lifespan compared to untreated steel, particularly in outdoor environments like gardens or garages. Because the zinc acts as a barrier, galvanised steel products require less frequent maintenance than standard steel – typically just occasional cleaning. It’s also heavier than non-treated steel, which can be an important factor when considering installation and weight limits. The zinc coating adds to the overall cost of the product.