FLAT CONCRETE ROOF WITH SUSPENDED CEILING – CR013A
Dow Styrofoam RTM-X or Dow Roofmate SL-X
| Preparation | Ensure membrane is clean and free of loose material. |
|---|---|
| Installation: | Lay insulation boards in brick pattern with square edges pushed together firmly, cut neatly around penetrations and extended up upstands. |
| Separation layer: | Lay ProctorWrap IRMA over insulation with edges lapped 300mm and turned down at upstands and penetrations. |
| Insulation | Dow Styrofoam RTM-X or DOW Roofmate SL-X |
| Total R-Value | [Complete] |
| Above Slab R-Value | [Complete] |
| Roofs with insulating membrane protection are also known as IRMA (inverted roof membrane assembly) or PMR (protective membrane roof).Specify separation layer in the Waterproofing – external and tanking worksection, or delete if not required. Using Dow Styrofoam RTM-X above the slab will minimise the risk of condensation below the slab. Care, should be taken in allowing builders to remove insulation above the slab as condensation may result in toxic mould formation. [Size] – Determined by required material R-value and k-value. In a ventilated space, the reflective foil values are diminished. | |
FLAT CONCRETE ROOF WITH SUSPENDED CEILING – CR012A
| Preparation | Ensure membrane is clean and free of loose material. |
|---|---|
| Installation: | Lay insulation boards in brick pattern with square edges pushed together firmly, cut neatly around penetrations and extended up upstands. |
| Separation layer: | Lay ProctorWrap IRMA over insulation with edges lapped 300mm and turned down at upstands and penetrations. |
| Insulation | Dow Styrofoam RTM-X |
| Total R-Value | [Complete] |
| Above Slab R-Value | [Complete] |
| Insulation | Dow Tuff-R |
| Below Slab R-Value | [Complete] |
| Roofs with insulating membrane protection are also known as IRMA (inverted roof membrane assembly) or PMR (protective membrane roof). Specify separation layer in the Waterproofing – external and tanking work section, or delete if not required. Using Dow Styrofoam RTM-X above the slab will minimise the risk of condensation below the slab. Care, should be taken in allowing builders to remove insulation above the slab as condensation may result in toxic mould formation. [Size] – Determined by required material R-value and k-value. In a ventilated space, the reflective foil values are diminished. | |
PITCHED TILED ROOF WITH CATHEDRAL CEILING BELOW RAFTERS – CR003B
Dow Styrofoam RTM-X SMTGRoofmate-X
| Location | To tile roof structure |
|---|---|
| Material Sarking Membrane: | ProctorWrap HT breathable (vapour permeable) membrane or equivalent with vapour resistance of not more than 0.26MNs/g |
| Installation: | Lay horizontally across rafters starting at eaves. Secure in place with battens in accordance with AS/NZS 4200.2 and product user guide. Avoid blockages that would prevent free drainage of moisture. |
| Thermal Insulation: | Dow Styrofoam Roofmate |
| Total R-Value | [Complete] |
| Fixing | Screw fix between counter batten and rafter. |
| Insulation | See manufacturers details in conjunction with finishes. |
DCT recommend a condensation risk analysis is undertaken to determine if a vapour barrier is required at the ceiling. Foil backed bulk insulation has a high risk of condensation if there is less than 2/3 of the total insulation on the cold side of the foil. There are a large number of factors that need to be considered in assessing and managing condensation risk. Such factors include the local climate, building use, position, thickness and type of insulation, position and integrity of vapour barriers, and the degree and location of mechanical or passive ventilation both in the roof space and the interior. It is highly recommended that designers undertake a condensation risk analysis. |
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