Insulated modular storage without environmental controls

Paula Sagerman <redfish [at] together__net> writes

>The Brattleboro Historical Society (VT, USA) would like to use part
>of an old barn for storage of archival materials if there is a way
>to protect the materials from deterioration.  We have paper,
>textiles, furniture, etc.  In order to protect the building
>envelope, we are considering building a "box within a box" using
>insulated, sheet-rocked walls and ceiling.  However, there will not
>be any climate control. Are any materials safe in this situation?

Our strongrooms are in a brick-built basement in England, much more
temperate and better insulated than a barn in Vermont, but I have
noticed one feature which might be relevant to your collections: the
capacity for cellulose-based materials to buffer their own
environment. One of our strongrooms was originally half-empty, with
a small humidistat-regulated dehumidifier in residence, and
(depending on where we took our RH readings) we got quite a wide
variation. The next strongroom has no dehumidifier, but is packed
full, and our hygrometers always read between 55% and 62%. On
several occasions, however, I've noticed that some of the boxes near
the end wall felt perceptibly cool. This suggests that the archives
themselves are 'taking up the slack,' and that our readings are
misleading for preservation purposes. They condition the whole
room--quite a different problem from pocket microclimates where a
box can feel normal on the corridor side and be actually damp where
it nudges a condensing wall. Might it be useful to acquire a set of
readings in the empty barn, and then compare them with a similar
set, taken at the same seasons, when the barn is full? It could show
how much the material is actually affecting/affected by its
environment.


                                  ***
                  Conservation DistList Instance 13:45
                 Distributed: Friday, February 25, 2000
                       Message Id: cdl-13-45-012
                                  ***