Is All Hemlock the Same? And Can It Go Outdoors?
Hemlock on its own isn’t ideal for outdoor use, but thermal modification changes that. Here’s what 5 independent sources say so you can decide for yourself.
Source 1/5
The Global Standard Says Yes.
Thermally modified timber is “suitable for both indoor and outdoor use, in all climates”. Its ideal uses include “cladding, saunas and outdoor structures”.
Source: International ThermoWood Association.
Read the source at thermowood.com
WHY IT MATTERS
Thermal modification is the step that takes timber from indoors to outdoors.
Source 2/5
Rated for Outdoor Use in Australia.
Thermally modified hemlock is “extremely stable and weather resistant” and rated suitable for external use.
Source: Modinex, Australian timber supplier.
Read the source at modinex.com.au
WHY IT MATTERS
Australian timber suppliers rate thermally modified hemlock for outdoor use.
Source 3/5
Same Tree. Completely Different Timber.
On its own, hemlock is “not very durable outdoors”. Once thermally modified it “becomes exceptionally durable, stable, and resistant to insects and decay”.
Source: Mataverde, US timber specialist.
Read the source at mataverdedecking.com
WHY IT MATTERS
A chart that rates untreated hemlock tells you nothing about a thermally modified hemlock sauna.
Source 4/5
Changed at the Cellular Level.
Thermal modification “removes organic compounds from the wood cells”. That is why the timber stays stable and holds up to moisture outdoors.
Source: SWP, US timber cladding specialist.
Read the source at swp.net
WHY IT MATTERS
Thermally modified hemlock is trusted on the outside of homes.
Source 5/5
Trusted on Homes for 20 Years.
Thermally modified hemlock cladding carries a “20-year limited warranty” on the outside of homes.
Source: UFP Edge, US building products company.
Read the source at ufpedge.com
WHY IT MATTERS
Timber makers stand behind thermally modified hemlock outdoors for decades.
Thermally Modified Hemlock vs Untreated Hemlock.
Sources: Modinex, Mataverde, The Wood Database and the International ThermoWood Association.
Thermally Modified Hemlock
Untreated Hemlock
Thermally Modified
Yes
No
Suitable for External Use
Yes
No
Decay Resistance
Resists decay
Non-durable
Weather Resistant
Extremely stable
Not durable outdoors
Built for Outdoor Saunas
20 years fully exposed
Indoor saunas
Not All Hemlock Is the Same.
Untreated hemlock isn’t ideal for outdoor use. Thermally modified hemlock is built for the outdoors. It is the only hemlock we use.
Here is what goes into every Nova Sauna:
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✓
Thermally Modified Canadian Hemlock or Red Cedar
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✓
100% Canadian Timber
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✓
Full-Length Staves With No Finger Joints
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✓
38mm Walls
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✓
Fully Assembled and 15-Point Checked
6 Months in the Weather. No Cracks.
Three hemlock owners. Three different climates.
Ryan, Melbourne: six months in and “there’s been no cracks… it looks brand new still”.
Simon, Sunshine Coast: “really exposed to the sun and the rain and it’s held up really well”.
Jack, Canberra: “over six months and hasn’t missed a beat”.
Every Nova hemlock sauna is built to last 20 years fully exposed.
