Redoing a ceiling is good. Insulating it is better.

Four questions to ask before signing

A ceiling quotation almost never says whether the insulation will be effective. Four simple questions are enough to find out, and they are asked before signing, because none of them can be answered once the ceiling is closed.

Will the plenum be closed

Insulation fitted in a volume open to the loft or to a construction void loses most of its value. The question is about the perimeter, the corners and the returns, not about the product itself.

Will there be an air gap

A reflector pressed against the facing no longer reflects anything useful. There must be a void in front of its bright face, and that void is part of the system just as the product is. A serious quotation mentions it.

How will the overlaps be treated

Two widths laid edge to edge leave an open line. The overlap and the tape turn a succession of strips into a continuous membrane, and it is that continuity which produces the measurable result.

What happens at the penetrations

Every downlight, every conduit and every duct creates an opening. Knowing how they will be made good says more about a firm's standard of care than any commercial reference.

Why these questions are worth it

They need no technical knowledge and they steer the answer. A professional who deals with them spontaneously has understood the system; another will discover the subject during the works, which always costs more. There is no need to ask them as an inspection either: they are put as requests for detail, and a good tradesperson answers them willingly.

Airtightness is developed on the dedicated page, and the product on its data sheet.