On Mon, 11 Jun 2012 10:28:20 -0500, Swingman wrote:

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.

I thougnt that's what the "I" in SIP stood for - - - .

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.