Extruded Polystyrene Insulation for Use in Flat Roof Waterproofing Applications
Extruded Polystyrene for use in concrete roof, deck and balcony insulation
referred to as "upside down , irma or prma roofs" this method of insulated
roofing simply means the insulation is placed above the waterproofing membrane
and held in place by a specified ballast, usually river pebbles or concrete
Metric xps insulation maintains its ability to insulate in the presence of
water. This, plus its high load bearing strength, makes it excellent insulation
for all roofing applications.
to maintain its physical properties and a minimum 90% R value for a period of
20 years. Foamular Metric has superior performance to expanded polystyrene
ensuring long term cost and insulation efficiency.
Metric thermal resistance (R value) are as follows:
40/R1.42 , 50mm/R1.78 , 60mm/R2.14 , 75mm/R2.67 , 100mm/R3.56
can be laid in 2 layers to achieve a specific R Value. Eg 40mm plus 50mm =
R values are for the Foamular Metric insulation material only. The components
of a common concrete roof assembly would add approx R0.5 to the above r values.
yet tough and durable Foamular metric boards are easy to hoist, handle and
Install. The boards add little weight to the overall roof structure while
providing long term protection to the waterproofing membrane. Board size is
2450 x 600 in thicknesses from 25 to 100mm.
Application is simple, quick, cost effective and energy efficient.
1: The specified membrane is laid over the concrete slab and covered by a bond
2: Foamular metric extruded insulation boards are loose laid over the membrane
and slip-sheet. The insulation boards protect the membrane from degradation and
weathering as well as insulating the concrete slab. Common practice is to run 2
layers of the boards in alternate directions with the thicker boards as the
3: Suitable filter fabric is laid over the insulation to prevent fines and grit
being washed down damaging the membrane. Black colored fabric should not be
used, grey color is preferred.
4: The specified ballast is spread over the roof. The ballast may be clean
round river pebbles, concrete pavers placed directly on the insulation or
pavers supported on spacer pads to allow additional drainage.
above application is a very basic explanation of the procedure. Individual
projects will have design requirements specific to that project however certain
procedure must be followed in all cases in respect to the insulation boards.
procedures are CRITICAL: ESPECIALLY DURING HOT WEATHER
Prior to laying, insulation boards and membrane must be checked for
Insulation must be covered with filter fabric and ballast directly after
laying. The material must not be left exposed to direct sunlight especially
during the summer months. Damage to the boards will result.
Material MUST be stored in an undercover area away from direct sunlight. Boards
may buckle or distort if left exposed to summer heat.
will be specified by architect / engineer but generally the gravel will be clean
rounded river pebbles 20-40 mm. Thickness of 50mm for insulation up to and
including 50mm, 75mm thick for 75mm -100mm insulation. Concrete Pavers should
be a 40-50mm thick as a minimum.
AND THERMAL COMBINATIONS Building design is now incorporating both acoustic and
thermal insulation for roofs, decks and balconies. What this requires is the
use of a sound absorbing material, eg regupol, to be included in the membrane,
insulation and ballast system. A number of combinations may be specified sometimes
with waterproofing both below and above the insulation materials.
TRAFFIC Foamular metric is available in various compressive strengths to meet
specific live and dead load requirements . For most applications with foot
traffic , 300kpa material will suit. For projects where vehicular traffic will
use area, such as parking or plaza decks, Foamular metric is available in
higher compressive strengths to meet those specifications. ( up to 650kpa)
OF SIMILAR INSULATION Foamular metric extruded polystyrene insulation is a
closed cell extruded polystyrene. This closed cell structure gives Foamular
superior physical and thermal properties that guarantee ongoing long term
Applications of Foamular Metric:
Under slab / under floor insulation -
commercial and residential.
Render substrate - external insulation
perfect for render coat.
Cold storage and Cool room insulation.
Wine cellars, chicken sheds and model