General guidance only — all construction work must be overseen by a supervising engineer This handbook is compiled from standards and laws with every source cited, andis being reviewed for certification by engineers Use it to know what to look at, what to ask and what evidence to request on site It is not an engineering determination and can't replace an engineer · Terms of use · Limitations of the handbook

Roofing

Heat insulation and ventilation under the roof

Page code P31 · 40 inspection criteria · 4 illustrations

Houses in hot cities take in more heat through the roof than any other way, but what really blocks it sits in a different layer from where most people spend their money. People tend to pay a lot for the roof covering, when the best-value layer is the ceiling and the roof space. The good news about this page is that everything can be decided before…

This page contains
Three layers that block heat — and the layer people most often spend money on wrongly
Insulation on the ceiling and reflective foil — different jobs, not a choice between them
Air inlets and air outlets — having only one is the same as having none
Things on the ceiling that insulation must not cover — decide before the insulation goes up
Moisture under the roof — a problem that shows up in year two
Measure it yourself with things you already have
Documents and photos you must get for this

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