Trade Select Sarking HVB High Vapour Barrier
1350 mm x 60 m (81 m²)
$187.00
Sale price
$187.00
Regular price
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Trade Select Sarking HVB High Vapour Barrier
$187.00
Sale price
$187.00
Regular price
GST inclusive
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Australia-wide freight · Local pickup from Epping, VIC by arrangement. Ordering from the outback? Get in touch about deliveries to remote locations · Shipping details
Trade Select Sarking HVB is the tightest membrane Ametalin make in this range. Class 1 vapour barrier at 0.002 µg/N·s, extra heavy duty, one size at 1350 mm x 60 m covering 81 m².
Class 1 is a different order of tightness
The vapour classes run 1 to 4, with Class 1 the tightest barrier and Class 4 the most permeable. Most reflective sarkings sit at Class 2. HVB is Class 1, roughly twice as tight again as the standard Sarking HD. That is what you want over a cool room, a swimming pool hall, a food processing area or any building where the inside carries far more vapour than the outside and it must not reach the structure.
Extra heavy duty
Tensile strength 15.2 kN/m machine direction against a 13.0 kN/m minimum, edge tear 646 N against 90 N, nominal thickness 0.17 mm.
Where it is the wrong choice
A Class 1 barrier on the outside of a wall that also has a vapour barrier on the inside traps moisture between them with no way out. HVB belongs on the warm side of the insulation, or in a roof detail designed around it. If the assembly is meant to dry outward, use a permeable membrane such as VapourTech Brane VHP.
On site
Ametalin declare RT 0.93 winter and RT 1.51 summer for an unventilated 22 degree residential roof, and RT 2.93 winter for a brick veneer wall with an R2.7 batt. Tape every join and seal every penetration, because a Class 1 barrier with holes in it is not a Class 1 barrier. It is electrically conductive, so keep it clear of wiring. Full figures are in the table below.
Technical data
Ametalin technical data sheet (PDF)Sizes stocked
| Roll size | Coverage | Product code |
|---|---|---|
| 1350 mm x 60 m | 81 m² | TSXHD-HVB-81 |
Barrier classifications
| Vapour control | Class 1 Vapour Barrier (ASTM E96) |
|---|---|
| Vapour permeance | 0.002 µg/N·s |
| Water control | Water Barrier (AS/NZS 4201.4:1994) |
| Air control | Air Barrier (AS/NZS 4200.1:2017) |
| Electrical conductivity | Conductive |
Strength
| Duty classification | Extra Heavy (AS/NZS 4200.1:2017) |
|---|---|
| Material thickness | 0.17 mm |
| Tensile strength machine direction | 15.2 kN/m (min 13.0 kN/m) |
| Tensile strength lateral direction | 12.4 kN/m (min 10.5 kN/m) |
| Edge tear machine direction | 646 N (min 90 N) |
| Edge tear lateral direction | 555 N (min 90 N) |
Fire
| Flammability index | Low, at or below 5 (AS 1530.2-1993) |
|---|---|
| Bushfire areas | All BALs (AS 3959-2018) |
Seek independent advice on sarking selection before installation in a BAL design.
Thermal, declared total system R-value
| Residential roof, 22 degree pitch, unventilated | RT 0.93 winter, RT 1.51 summer |
|---|---|
| Brick veneer wall plus R2.7 batt | RT 2.93 winter, RT 2.78 summer |
| Emittance | Anti-glare side 0.90, foil side 0.03 |
| Emittance category | RN |
Calculated to AS/NZS 4859.2:2018 for typical mainland capital city conditions. The reflective face only contributes when it faces an air cavity.
Durability
| Wet delamination | Pass (AS/NZS 4201.2:1994) |
|---|---|
| Shrinkage, repeated wetting and drying | 0.0% (limit under 0.5%) |
Compliance
| Standards | AS/NZS 4859.1:2018 and AS/NZS 4200.1:2017 |
|---|---|
| NCC | Meets NCC requirements for pliable building membranes, insulation and sarking-type materials |
Fitting notes
Install to AS 4200.2 Pliable Building Membranes and Underlays, Part 2. Tape every join and seal every penetration, because an unsealed Class 1 barrier does not perform as one. Keep the foil face to an air cavity so the reflective side can work. The product is electrically conductive, so keep it clear of wiring. Store the rolls undercover in a clean dry place in the pack provided, away from cement, mortar and other alkaline products.
Figures are taken from the Ametalin technical data sheet for Trade Select Sarking HVB, TPM-23249-1, product code TSXHD-HVB. The manufacturer document is linked above. Ametalin can change specifications without notice, so check the current sheet before specifying on a job.
Common questions
What does HVB stand for?
High Vapour Barrier. It is a Class 1 vapour barrier at 0.002 µg/N·s, the tightest class in AS/NZS 4200.1.
How much tighter is Class 1 than Class 2?
On these sheets, HVB is 0.002 µg/N·s against 0.004 for Sarking HD and 0.012 to 0.0152 for the wall wraps. Class 1 is the barrier you specify when vapour must not pass at all.
When would I use it instead of ordinary sarking?
Where the inside of the building carries far more vapour than the outside. Cool rooms, indoor pools, food processing and similar. For a normal house roof, Sarking HD is the usual choice.
Can I use it with an internal vapour barrier as well?
Be careful. Two barriers with insulation between them and no drying path can trap moisture. Get the wall or roof build-up checked by the designer before doubling up.
Is it strong enough for a roof?
Yes. Extra Heavy duty, 15.2 kN/m tensile and 646 N edge tear against a 90 N minimum.
Can I use it in a bushfire area?
Yes. Flammability index Low, at or below 5, and it complies with AS 3959-2018 for all BALs. Take independent advice on sarking selection before locking in the BAL design.
Cannot see your question? Ask our team and we will get you an answer.
Answers use the Ametalin technical data sheet for Trade Select Sarking HVB, TPM-23249-1.
