Common Building Materials Vapor Permeance Table

Vapor permeable sarking/wraps or building products on the EXTERIOR of WALLS are designed to allow water vapor to diffuse through them, which can be beneficial in managing moisture within wall systems.

This capability is particularly important in hotter humid climates compared with colder climates for several reasons:

In colder climates:

1. Prevent Moisture Accumulation – When warm, moist air from inside the building comes into contact with cold exterior walls, it can condense into water. If the wall system can’t effectively allow this moisture to escape, it can build up, leading to mold growth and structural damage. Vapor-permeable materials on the outside let this moisture diffuse out of the wall, reducing these risks.
2. Dry-out Capability – If any moisture does penetrate the wall system (such as from driving rain), vapor permeable materials enable the wall to dry to the outside, preventing water from being trapped and causing decay or corrosion over time.
3. Adaptability – These materials can respond to changes in humidity and temperature, adjusting their permeability as needed to facilitate optimal moisture management within the wall system.
4. An airtight vapor permeable wrap reduces wind washing of insulation.
   

In warmer climates:

1. Humidity Management – In humid conditions, A vapour retarder exterior can help prevent the buildup of moisture within the wall assembly, reducing the potential for mould and structural issues.
2. Balance of Airflow – By allowing walls to breathe, these materials help maintain airflow balance within the wall system, which contributes to a more stable and comfortable indoor environment.

Vapor barriers on the INSIDE of WALL systems, conversely, play different roles in cold and warm climates:

In colder climates:

• Preventing Condensation – A vapour barrier on the inside of the wall helps prevent the diffusion of moist indoor air into the colder wall cavities, where it can condensate and lead to water damage.
• Energy Efficiency – By creating a more airtight environment, vapor barriers can reduce the amount of heat lost through walls, thereby increasing energy efficiency and reducing heating costs.

In warmer climates:

• a Vapor Barrier inside the wall system is less beneficial to an indoor healthy environment.
  
• a Vapor Permeable internal air barrier is beneficial in warm, humid environments because it allows a wall to at least dry to the inside.In summary, the combination of vapor permeable materials on the outside and vapor barriers on the inside of wall systems helps to manage moisture levels effectively, protect structural integrity, and maintain energy efficiency regardless of climate conditions. Each component ensures an optimal balance between preventing unwanted water ingress and allowing moisture within the wall to escape, thereby contributing to overall building durability and occupant comfort.

Here is a table of common construction products coupled with the vapor permeance capabilities.

Class	VCM Category	Min. (>=)	Max. (<)
Class 1	Vapour Barrier	0.0000	0.0022
Class 2		0.0022	0.1429
Class 3	Vapour Permeable	0.1429	1.1403
Class 4		1.1403	No max.
	ASTM-E96 Method B Wet Cup - 28 C 50%RH

Building Materials Water Vapour Resistance Table

Test samples		Thickness	Mean permeance (µg/N.s)	US Perms	AS4200.1 Classification	NCC Climate Zone 4-5 Applicable (Class 3 or 4)	NCC Climate Zone 6, 7 and 8 Applicable (Class 4)	Airtight
Gyprock Aquacheck	No paint	10mm	2.284	39.93006993	Class 4	Yes	Yes	Yes
Siniet Wet Zone Plaster 13mm	No paint	13mm	2.355	41.17132867	Class 4	Yes	Yes	Yes
Aquacheck - 2 Base Coats	Primer white Paint	10mm	1.083	18.93356643	Class 3	Yes	No	Yes
Aquacheck - 2 Base Coats - Mould Resistive Paint	Primer white Paint + bathroom Paint	10mm	1.059	18.51398601	Class 3	Yes	No	Yes
Standard Plaster - Spray on special white Liquid Membrane 2 coats	2A Written on Label	10mm	0.612	10.6993007	Class 3	Yes	No	Yes
Standard Plaster - Black Special Membrane 2 coats	3A Written on Label	10mm	0.237	4.143356643	Class 3	Yes	No	Yes
Standard Plaster - 2 Base Coats	Primer white Paint	10mm	1.1418	19.96153846	Class 4	Yes	No	Yes
No Sealer, 3 Coats Special Paint	Vapour Tight	10mm	0.147	2.56993007	Class 3	Yes		Yes
Sealer + 2 coats Special Paint	Vapour Tight	10mm	0.134	2.342657343	Class 2	Yes		Yes
Proclima Intello Plus	Vapour Barrier or Vapour Permeable	0.4 +/- 0.15 mm	0.8 - <0.008	13.98601 - <0.13986	Class 2 - Class 3	Yes*	No	Yes
Proclima Intello Connex	Vapour Barrier	< 1 mm	0.0709	1.23951049	Class 2	No	No	Yes
Proclima Solitex Extasana	Vapour Permeable	0.595 mm - 0.605 mm	2.179	38.09440559	Class 4	Yes	Yes	Yes
Proclima Solitex Extasana Adhero	Vapour Permeable	0.595 mm - 0.605 mm	2.179	38.09440559	Class 4	Yes	Yes	Yes
Proclima Aerosana Visconn	Vapour Barrier	0.2 - 1 mm wet film	0.0303 - 0.03704 @ 0.3 mm	5.297203 - 6.475524 @ 0.3 mm	Class 2	No	No	Yes
Proclima Solitex Mento Plus	Vapour Permeable	0.5 mm - 0.7 mm	1.429	24.98251748	Class 4	Yes	Yes	Yes
Proclima Solitex Mento 5000	Vapour Permeable	0.6 mm - 0.8 mm	1.153	20.15734266	Class 4	Yes	Yes	Yes
Proclima Solitex Mento Ultra	Vapour Permeable	0.8 mm - 1 mm	1.3072	22.85314685	Class 4	Yes	Yes	Yes
Proclima Solitex UM Connect	Vapour Permeable	N/A	Not Provided	Not Provided	N/A
Proclima DA	Vapour Barrier	0.4 mm - 0.5 mm	0.0853	1.491258741	Class 2	No	No	Yes
Passive Purple External		Two Layers	Not Provided	Not Provided	Not Provided
Passive Purple	Vapour Barrier	Two Layers, 0.5 - 1 kg/m^2	0.005714 - 0.01	0.099895 - 0.174825	Class 2	No	No	Yes
Proctor Smart Vap 100	Vapour Permeable	0.3 mm	0.55	9.615384615	Class 3	Yes*	No	Yes
Proctor RW/RW-IT	Vapour Permeable	0.4 mm	2.983	52.15034965	Class 4	Yes	Yes	Yes
Proctor CW/CW-IT	Vapour Permeable	0.5 mm	3.019	52.77972028	Class 4	Yes	Yes	Yes
Proctor HTS/HTS-IT	Vapour Permeable	0.6 mm	2.565	44.84265734	Class 4	Yes	Yes	Yes
Proctor Wraptite SA	Vapour Permeable	0.65 mm	4.1	71.67832168	Class 4	Yes	Yes	Yes
Proctor Wraptite UV-SA	Vapour Permeable	0.38 mm	1.5	26.22377622	Class 4	Yes	Yes	Yes
Proctor HTR	Vapour Permeable	0.99 mm	3.71	64.86013986	Class 4	Yes	Yes	Yes
ProctorGeo Vap 120	Vapour Barrier	0.32 mm	0.02	0.34965035	Class 2	N	N	Yes
Proctor RS-IT	Vapour Permeable	0.5 mm	2.78	48.6013986	Class 4	Yes	Yes	Yes
Proctor PyroPerm A2	Vapour Permeable	0.4 mm	1.426	24.93006993	Class 4	Yes	Yes	Yes
ProctorGeo IRMA	High Vapour Permeability	0.38 mm	Not Provided	Not Provided	N/A	N	N	N
Bradford Thermoseal FireSpec Wall Wrap & Roof Sarking	Vapour Barrier	< 1 mm	Not Provided	Not Provided	Class 2	No	No	Yes
Bradford Light Duty Facing 729	Vapour Barrier	< 1 mm	Not Provided	Not Provided	Class 1	No	No	Yes
Bradford Medium Duty Facing 730	Vapour Barrier	< 1 mm	Not Provided	Not Provided	Class 2	No	No	Yes
Bradford Medium Duty Facing 730 Perforated (Facing Product)	Aesthetic or Acoustic Property	< 1 mm	N/A	N/A	N/A	N/A	N/A	No
Bradford Heavy Duty Facing 750	Vapour Barrier	< 1 mm	Not Provided	Not Provided	Class 1	No	No	Yes
Bradford Heavy Duty Facing 753 Perforated (Facing Material)	Aesthetic or Acoustic Property	< 1 mm	N/A	N/A	N/A	N/A	N/A	No
Bradford Medium Duty Facing 750 Perforated (Facing Product)	Aesthetic or Acoustic Property	< 1 mm	N/A	N/A	N/A	N/A	N/A	No
Bradford Thermoseal 756 HD (Facing Product)	Vapour Barrier	< 1 mm	Not Provided	Not Provided	Class 2	No	No	Yes
Bradford Thermoseal 756 HD Perforated (Facing Product)	Aesthetic or Acoustic Property	< 1 mm	N/A	N/A	N/A	N/A	N/A	No
Bradford Thermoplast 990F White Perforated (Facing Product)	Aesthetic or Acoustic Property	< 1 mm	N/A	N/A	N/A	N/A	N/A	No
Bradford Thermoplast 990F White (Facing Product)	Vapour Barrier	< 1 mm	Not Provided	Not Provided	Class 2	No	No	Yes
Bradford Thermoplast 993 Black Perforated (Facing Product)	Aesthetic or Acoustic Property	< 1 mm	N/A	N/A	N/A	N/A	N/A	No
Bradford Thermoplast 993 Black (Facing Product)	Vapour Barrier	< 1 mm	Not Provided	Not Provided	Class 2	No	No	Yes
Bradford Thermoplast 993F White Perforated (Facing Product)	Aesthetic or Acoustic Property	< 1 mm	N/A	N/A	N/A	N/A	N/A	No
Bradford Thermoplast 993F White (Facing Product)	Vapour Barrier	< 1 mm	Not Provided	Not Provided	Class 2	No	No	Yes
Ametalin CeaseFire	Vapour permeable wall and roof membrane	0.17 mm	1.5767	27.56468531	Class 4	Yes	Yes	Yes
Ametalin Vapour Tech RWC Roof Wall Commercial	Air Barrier and Water Barrier	0.83 mm	2.144	37.48251748	Class 4	Yes	Yes	Yes
Ametalin Vapour Tech Wall	Air Barrier	0.45 mm	3.764	65.8041958	Class 4	Yes^	Yes	Yes
Ametalin Vapour Tech Brane VHP	Air Barrier	0.38 mm	12.85	224.6503497	Class 4	Yes^	Yes	No
Ametalin Fire Sark Micro - perforated	Vapour Permeable reflective wrap	0.2 mm	0.8698	15.20629371	Class 3	Yes^	Yes	No
Ametalin Sliver Wrap Micro - perforated XHD	Vapour Permeable reflective wrap	0.17 mm	0.5727	10.01223776	Class 3	Yes^	Yes	No
Ametalin Sliver Wrap Micro - perforated HD	Vapour Permeable reflective wrap	0.12 mm	0.3341	5.840909091	Class 3	Yes^	Yes	No
Ametalin Sliver Wrap Micro - perforated MD	Vapour Permeable reflective wrap	0.1 mm	1.717	30.01748252	Class 4	Yes^	Yes	No
Ametalin Sliver Wrap Micro - perforated LD	Vapour Permeable reflective wrap	0.09 mm	1.6	27.97202797	Class 4	Yes^	Yes	No
Ametalin Sliver xR Wrap Micro - perforated HD	Vapour Permeable reflective wrap	0.12 mm	1.45	25.34965035	Class 4	Yes^	Yes	No
Ametalin Sliver xRS Wrap Micro - perforated MD	Vapour Permeable reflective wrap	0.1 mm	0.2028	3.545454545	Class 3	Yes^	Yes	No
Ametalin SilverSark HVB	Vapour Barrier	0.17 mm	0.002	0.034965035	Class 1	No	No	Yes
Ametalin SilverSark XHD	Vapour Barrier	0.17 mm	0.02121	0.370804196	Class 2	No	No	No
Ametalin SilverSark HD	Vapour Barrier	0.12 mm	0.004	0.06993007	Class 2	No	No	No
Ametalin Silver Wrap MD	Vapour Barrier	0.10 mm	0.0131	0.229020979	Class 2	No	No	No
Ametalin Silver Wrap LD	Vapour Barrier	0.09 mm	0.0152	0.265734266	Class 2	No	No	No
Ametalin Fire Sark	Vapour Barrier	0.2 mm	0.003	0.052447552	Class 2	No	No	No
Outback Building Wrap BM	Vapour Permeable		5.55	97.02797203	Class 4	Yes	Yes	Yes
Outback Building Wrap BML	Vapour Permeable		1.01	17.65734266	Class 3	Yes	No	Yes
Hardie Wrap Weather Barrier	Vapour Permeable	< 1 mm	1.695	29.63286713	Class 4	Yes	Yes	Yes
James Hardie Hardie Backer 1/4 In Cement Board		6.5 mm	0.09975	1.743881119	Class 2	No	No	Yes
James Hardie Hardie Backer 500 Cement Board		11 mm	0.16188	2.83006993	Class 3	Yes	No	Yes
James Hardie Rigid Air Barrier Board	Rigid Air Barrier	6 mm	0.95	16.60839161	Class 3	Yes	No	Yes
Aerated Concrete 460 kg/m^3 (50% Humidity)	Vapour Permeable	3	1.13	19.75524476	Class 3	Yes	No	No
Cemintel Rigid Air Barrier	Rigid Air Barrier	6 mm	0.25	4.370629371	Class 3	Yes	No	Yes
Save Board Better Brace Rigid Air Barrier	Air Barrier	10 mm	Not Provided	Not Provided				Yes
DuPont Tyvek Homewrap	Air Barrier, Vapour permeable	0.14 mm	2.8	48.95104895	Class 4	Yes	Yes	Yes
DuPont Tyvek Supro Wall Underlays	Vapour Permeable	0.45 mm	3.7	64.68531469	Class 4	Yes	Yes	Yes
DuPont Tyvek Pro Wall Underlays	Vapour Permeable	0.38 mm	4.5	78.67132867	Class 4	Yes	Yes	Yes
Siga Majrex 200 (Direction 1 Wet Cup Method)	Vapour Permeable	0.3 mm	0.2166	3.786713287	Class 3	Y	No	Yes
Siga Majrex 200 (Direction 2 Wet Cup Method)	Vapour Permeable	0.3 mm	0.0741	1.295454545	Class 2	No	No	Yes
Siga Majvest 200	Vapour Permeable, Water resistive air barrier	0.5 mm	3.876	67.76223776	Class 4	Yes	Yes	Yes
Siga Majvest 500 SA	Vapour Permeable, Water resistive air barrier	0.7 mm	1.368	23.91608392	Class 4	Yes	Yes	Yes
SIga Majvest 700 SOB	Water Resistive Barrier	0.5 mm	6.1204	107	Class 4	Yes	Yes	Yes
Siga Wetguard 200 SA	Moisture Protection Membrane for timber	0.5 mm	0.02797	0.488986014	Class 2	No	No	Yes
Weather Defence	Vapour Permeable	13 mm	Not Provided	Not Provided	Class 4	Yes	Yes	Yes
Multishield		13 mm or 16 mm						Yes
Mastashield		10 mm or 13 mm						Yes
Opal		10 mm						Yes
Shaftliner		25 mm						Yes
Trurock		13 mm or 16 mm						Yes
Fireshield Heavy		13 mm						Yes
Soundshield		10 mm or 13 mm						Yes
Spanshield		10 mm						Yes
Trurock HD		13 mm						Yes
Watergate Plus	Vapour Permeable	< 1mm	> 0.1429	> 0.008174	Class 3 - Class 4	Yes	No	Yes
Covertek 407	Vapour Barrier	< 1mm	> 0.1429	> 0.008174	Class 3 - Class 4	Yes	No	Yes
Seal Grip	Vapour Barrier	5.3 mm wet, 1.6 mm dry	< 0.0572	< 1	Class 1 - Class 2	No	No	Yes
Insul Kote Vapor Barrier 530	Vapour Barrier	7 mm wet, 2 mm dry	0.01716	0.3	Class 2	No	No	Yes
Benjamin Moore Super Spec Vapor Barrier Primer Sealer 260	Vapour Barrier	0.09144 mm wet, 0.0254 mm dry	0.0286	0.5	Class 2	No	No	Yes
Sherwin Williams Moisture Vapor Barrier Interior Latex Primer Sealer	Vapour Barrier	6-8 mil wet, 1.6-2.1 mil dry	< 0.0572	< 1	Class 1 - Class 2	No	No	Yes

Please note, that the method of testing is not stipulated in this table, results may vary depending on testing method. (Vapour Permeance)

A very generic table of vapour permeance

Green Building Water Vapour Permeance Figures

Material	Permeance (perm) grain/ ft2 hr (in. Hg)	Permeance (µg/N.s)
Aluminium foil (1 mil)	0	0
Aluminium foil (0.35 mil)	0.05	0.00286
Polyethylene (6 mil)	0.06	0.003432
Polyethylene (4 mil)	0.08	0.004576
Polyethylene (2 mil)	0.16	0.009152
Asphalt kraft paper facing	0.3	0.01716
Unplasticised PVC (2 mil)	0.68	0.038896
Asphalt paint on plywood (2 coats)	0.4	0.02288
Aluminium paint (2 coats)	0.30 - 0.50	0.01716 - 0.0286
Latex VDR paint (1 coat)	0.45	0.02574
White lead/ oil paint on wood siding (3 coats)	0.30 - 0.99	0.01716-0.056628
White lead/ zinc oxide/ oil paint on wood siding (3 coats)	0.88	0.050336
Extruded polystyrene (1 in)	0.4 - 1.6	0.02288 - 0.09152
Polyutherane (1 in)	1.2	0.06864
25 mm (1 in) expanded polystyrene	2 - 5.79	0.1144 - 0.331188
100 mm (4 in) rock wool	28.97	1.657084
100 mm (4 in) cellulose fibre	28.97	1.657084
100 mm (4 in) glass fibre wool	28.97	1.657084
100 mm (4 in) glazed tile masonry	0.1 - 0.16	0.00572 - 0.009152
3 mm (1/8 in) cement board with oil paint	0.3 - 0.5	0.01716 - 0.0286
19mm (3/4 in) boaRD (wood)	0.3 - 4.03	0.01716 - 0.230516
Plywood, exterior glue, Douglas-fir (1/4 in)	0.7	0.04004
Brick (4 in)	0	0
Concrete block (8 in)	2.38	0.136136
Tar paper (15 lb)	4	0.2288
Hardboard (standard) (1/8 in)	10.96	0.626912
Spunbounded polyproplyene	15.37	0.879164
Sheathing paper, asphlalt saturated and coated	20.35	1.16402
Gypsum drywall	49.74	2.845128
Tyvek Home Wrap	77	4.4044
Commercial Wrap	28	1.6016

It is unknown what test method was used for these figures. Results were derived from the "Cold Climate Housing Research Centre - Alaska"

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