Swingman wrote in
:

On 6/11/2012 9:31 AM, HerHusband wrote:

I had a few immediate questions the article did not seem to address:

1. Insulation value. With less than 6" of solid wood, that's under an
R8 insulation value. There's probably some thermal mass, but it
doesn't seem like this system would be a good option in cold
climates.

Not an issue that has not already been solved in other types of solid
wall construction.

CLT construction is mostly done using CLT's for exterior walls only.
Most any wooden structure is going to require added insulation and CLT
construction is no different. With CLT construction, insulation is
usually added to the exterior of any "cold wall", underneath the
exterior cladding.


2. Utilities. As with a traditional log home, where to you run the
plumbing, electrical, and other services? You would either need to
build a secondary wall on the interior to provide space for these
(negating the advantages of the system), or restrict utilities to
interior walls. I suppose you could use surface mount conduit for
electrical, but that's not a good option for plumbing.

Not an issue ... most solid wall construction of any type, concrete
block, etc, exhibit the same service issues.

Service channels for CLT construction in exterior walls can actually
be routed into the CLT at the factory; and/or services can be run
between floors, in crawlspaces, in stick built interior walls, or
between thinner, sandwiched CLT interior walls; and/or in furred out
interior wall coverings, just to name a few methods.

IOW, there are many traditional method's to attack that issue that are
proven, cost effective, and viable.

3. The wood panels are touted as making efficient use of wood, but
common SIPS (structural insulated panels), use less wood, provide
better insulation, and offer at least some ability to route wiring
(though I still question the fire and insect resistance).

As long as you buy into using "sustainable" building materials for
structures, "using less wood" becomes much less of an issue.

As noted, insulation is also required in SIPS.

Fire is even less of an issue with CLT's and most other wooden wall
construction due to lack of oxidation and space to allow for flames to
feed on adjacent material ... that's why "fire blocking" is required
by all building codes in traditional wooden frame buildings.

Insects are a problem in most other building methods as well, and for
two main reasons: the building material itself is a source of food
and/or a source for nesting. Remove both reasons with proper measures,
including treatment with solutions like borates, and proper sealing,
and that issue is as easily mitigated in CLT construction as it is in
other construction methods.

The main thing this system seems to have going for it is strength,
which I'm sure there are good situations it could be used for. But I
would not want to build an entire house with them.

Although I have not personally used CLT's for construction, I have
built houses with non-traditional wall construction ("straw bale wall
construction" in particular, which is arguably more difficult to
effect than CLT construction) where many of the same issues you bring
up are easily solved; I've also attended, and done presentations
myself, at many Green building seminars, including use of CLT and SIP
construction methods.

IMO, you will much more of this as time goes on.

+1

--
Best regards
Han
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