What Record Should Exist of a Concealed Envelope

The framed wall record is the clearest about the purpose. A photographic record taken before closing, keyed to each elevation, is what a later air test result or damp investigation can be interpreted against. That is a statement about interpretation rather than about compliance: the record does not say the work was good, it says what the work was.

The cavity wall record makes the same point for the void, describing a record of the insulation arrangement, tie type, interception positions and outlet locations as what allows a later damp investigation to begin from evidence rather than from guesswork. The retrofit record goes further and says that where the record is thin, later damp diagnosis has nothing to work from.

The internal lining record asks for this in the most useful possible form for an owner. A finished insulated lining is indistinguishable from an ordinary wall, so a drawing of what was installed, where the control layer runs and where fixings may safely be made is what gives ordinary later work any chance of missing it.

The mass timber record asks for the equivalent where the structure is the barrier: recording what was built and where the barrier lines run is what makes later alteration possible without cutting into a structural air barrier. In both cases the useful drawing is one that can be read by somebody hanging a shelf, not only by a designer.

The cavity tray record identifies the weep openings as the only visible part of the arrangement, and notes that they are routinely filled during repointing, rendering or painting by someone who reads them as defects. Its conclusion is that recording their purpose is the only realistic protection an owner has.

The abutment record asks for something related but different: not the material of the flashing but who provided the concealed tray. The masonry wall record asks for interception positions and outlet locations. Together those three give an owner enough to answer the two questions that arise later, which are whether something is there and where what it collects is supposed to leave.

On a facade of near-identical units this is a practical necessity rather than an archive. The precast record states that a facade of near-identical units is easy to misread on site, and that the drawings are what distinguish one panel from its neighbour, asking for panel marks, fixing types and joint details. Without them no later intervention is straightforward.

The curtain walling record asks for the same in its own vocabulary: unit marks, glass types, gasket references and drainage details, because a facade of near-identical bays is difficult to describe after the fact and a later repair otherwise begins by identifying what is already there. The composite panel roof record adds the availability of matching panels as something worth establishing early.

This item is specific to work on existing buildings, and the retrofit record treats it as the whole evidence base. The survey findings, the fill placed, the treatment of openings and the reinstatement are described as the entire evidence base for a concealed alteration, and the record says plainly that what was found in the void is the only evidence anyone will have when a damp patch appears on an internal face long afterwards.

The internal lining record asks for the same before a wall is covered, describing a baseline record of the wall's condition as what makes later diagnosis possible, and noting that once complete the wall behind the lining cannot be inspected and any damp appearing outside is harder to interpret.

Two records ask for something that is neither a position nor a condition, but an intention. The attenuation roof record notes that a roof designed to hold water looks exactly like a defective roof, and asks for the fact that the behaviour is intended, and how the restriction works, to be recorded so that anyone arriving later has a reason not to clear it.

The trafficked deck record asks for the equivalent about access: which areas are intended to be lifted, where the outlets are, and how debris is removed from the void, because a later owner sees paving and nothing else. Both are records of intent, and both exist because the alternative is somebody helpfully undoing the design.

Every item on this list has a moment, and most of them are earlier than handover. The record of a void is made before the outer leaf closes. The record of a liner is made the day it is finished. The record of an inverted roof's waterproofing is made before the surfacing goes on, which is why its published question asks how the concealed layer will be checked before it is covered and what record will exist afterwards.

That is why asking for the record at handover is usually too late to create it and only just in time to receive it. The request belongs in the same conversation as the programme, alongside the question of when each layer becomes permanently concealed.

It cannot make an uninspected layer inspected, and it cannot substitute for a design assessment. The records are careful here: they ask for what was built, what was found and what was assumed, and they leave the interpretation to whoever is qualified to make it. The bridging record's phrasing is representative, asking for which junctions were considered and what was assumed, so that a later alteration does not require repeating the whole exercise.

It also cannot help anyone who does not know it exists. The internal lining record's observation that where the drawing is held decides whether it is ever consulted is the most practical sentence in the whole subject, and it applies to every item above.