The installation of the damp proof course is a key
stage of the building process, and one which really needs to be handled
with care and attention to detail. Any faults with the installation,
leading to damp ingress at a later stage, can be very expensive and
difficult to fix. We recommend that only high quality damp proofing
membranes that meet British Standards, and other building accreditations,
should be used as it is simply not worth the risk of using lower grade
product for this essential function.
Approved Document C of the Building Regulations 2000,
published 28 April 2006, sets out the requirements for site preparation
and resistance to contaminates and moisture - this can be seen on-line by
clicking the link below. Various methods of damp proofing for different
types of construction are illustrated and documented, and they provide a
good general guide to understanding what will need doing for your project.
Approved Document 'C'
The Damp Proof Membrane (DPM) must be installed in
conjunction with the Damp Proof Course (DPC) in the outer walls so as to
form a continuous layer. Where it is necessary to join sheets of the DPM,
first make sure that the surfaces to be joined are clean and free of
moisture. Overlap the sheets by at least 4 to 6" (100 to 150mm) and use a
double sided butyl tape or mastic strip compound to join the sheets
together to form a continuous waterproof barrier. The exposed overlap
joints can then be sealed using 4" (100mm) jointing tape. If any area of
the DPM is damaged during installation this should be patched by
overlaying a fresh piece of DPM to cover the damaged area and to overlap
by at least 6" (150mm) in all directions. Once again use double-sided
mastic strip, or butyl tape to create a waterproof barrier, and then seal
down the edges with jointing tape.
The damp proof membrane should normally be covered with
a layer of soft sand to act as a protection and to prevent damage when the
concrete flooring or screed are installed.
Buildbase supply a complete range of damp proof course
and damp proof membranes, including special membranes for use in areas
with requirements for installation of Radon and other protective barriers.
Links
Visqueen Building Products - Website
Ruberoid Building Products - Website |
