CPD Specifier May 2015 issue January 2014 | Page 16

Repair, Refurb, Retrofit

Dampness following the storms?

Eliminate damp affecting a wall under
an abutting roof line
The attachment to an existing exterior skin of
an extension results in the original exterior skin
becoming an internal wall below the new roofline.
If the abutting roof is flashed only, there is
nothing to prevent the penetrating wetness from
gravitating downwardly into the new extension.
To prevent dampness continuing its downward
movement within the masonry, an appropriately
shaped DPC is required.
The solution is to install cavity trays. There
are types for horizontal abutments (Type E)
and for sloping abutments (Type X). Both are
manufactured by the same company Cavity Trays
of Yeovil, the only tray manufacturer awarded
European Technical Approval.
Both approved trays have many novel features
that make the task of installation and compliance
easy, swift and economical.
The Type X cavitray has its own attached lead
flashing, ready-shaped and secured within a
protective bosem jaw. Once the tray is built-in,
the flashing requires only dressing. The Type X
cavitray is supplied with long flashings to dress
directly over shaped tiles or short flashings
for dressing over a secret gutter or soakers.
Importantly, all types benefit the bosem jaw
attachment and all flashings are shaped t