Curing
Aggressive Damp Penetration Externally at Primary School in South Wales
by Newton
Waterproofing Systems
The Alltwen
Primary School in Pontardawe, Swansea is located in a extremely exposed
area resulting in driving and penetrating dampness hitting the outer
fabric of the building and spoiling the internal render and finish to the
classrooms.
The Neath and Port Talbot District Council specified the external
application of Newton's Newlath 2000 to eradicate this problem as it had
been used successfully on other school projects where the same problem
existed. The membrane could not be applied internally because of the
disruption it would cause to teachers and pupils.
The membrane was
applied with skill and competence as the project required intricate
detailing in particular to the window coins. The fixing centres were
generally spaced at 200mm but reduced to 100-150mm in the demanding areas.
A 6:1:1 clean sharp sand, cement, lime mix was then applied in two coats
to the membrane with a rubbed float finish in preparation for decoration.
The contract was in excess of 250 square meters and the local authority
were delighted that the project came within their budget and was completed
ahead of schedule using the externally applied technique.
The existing substrate which was constantly saturated is now in the
process of drying out aided by the 5mm air gap created by the Newlath
2000. In addition any further attempts of moisture entering the building
fabric is repelled by the membrane. Great U values are now being achieved
with the membrane warming the interior of the school and no expensive
re-pointing was required.
This case
study has been submitted by a member and the British Structural
Waterproofing Association accepts no responsibility for its content.