[Greenbuilding] Glass ceiling

John Salmen terrain at shaw.ca
Sun Nov 18 17:54:31 CST 2012


I don't know what there is to take issue with. Old materials are toxic - we
can argue about the degree of toxicity and risk but that is what it comes
down to.  Wood cells store contaminants - and our history is one long list
of adding products to wood and all other material surfaces to make them
durable. Durability and longevity in the 20th century equates to toxicity
just as it did in previous centuries.

For example, it is getting better understood in the floor refinishing
industry that floors done before the 80's typically contain lead from the
finishes used and other heavy metals and workers have to protect
themselves?. Gets worse as you go back into the chemical heyday - floors
from the 50's and 60's contain pcb's as evidenced in elevated pcb levels in
people living on 'fabulon' and similarly finished floors. The actual depth
of the contamination is going to vary depending on what, how, where,
when.... but the reality is that wood is a sponge. So is stone. Put brown
solvent caulking under a 1 1/2" slab of white marble and wait a month or
two.

Etched and pressure treated wood is not a valid example of the intake of
chemicals into wood cell structures. Etching and pressure are two different
methods. Etching (death from the thousand cuts) is done to a depth roughly a
1/4" in north america to create a fungus treatment for a product where 1/4"
is considered sufficient protection. In Europe they go deeper. This is a
method for quickly treating wood and actual chemical penetration is deeper.
Pressure can result in greater depths. The traditional method used here in
bc up to the 90's at most sawmills was dip tanks and that could fully
saturate a full 2x4. This wood was exported all over the world (Europe did
not want moldy looking wood when they opened the containers).

The reclaiming of wood is not an industrial safety showplace. It is a
tertiary industry at best so we have backyard operations producing chips and
sawdust that goes where....

I apologize for sounding heavy and preachy about this and my emails get too
long - I've had to work around all this stuff for over 30 years and for me
green building started with a set of strongly held assumptions about how to
do things properly or differently - when you start looking at the products,
the chemicals, the economy, and the rationale you realize that you are
really just living in your time with a large set of contradictions and
compromises, but it helps to know what they are and being different is not
always a solution.

My shop is small and not a hazmat zone so I won't even begin to go near old
materials. Our renovation work is improving as a hazmat zone which is
actually not that difficult or even expensive to accomplish when it becomes
the goal. 



-----Original Message-----
From: Greenbuilding [mailto:greenbuilding-bounces at lists.bioenergylists.org]
On Behalf Of RT
Sent: November-18-12 9:38 AM
To: Green Building
Subject: Re: [Greenbuilding] Glass ceiling

On Sun, 18 Nov 2012 09:31:29 -0500, Tim Brown <tim34 at optonline.net> quoted:

> On Nov 17, 2012, at 10:41 PM, John Salmen who wrote:

>> Re-using and re-claiming is also not necessarily a good thing. Do I 
>> want a floor from wood that came from an old factory floor with cells 
>> filled with un-re-claimed heavy metals and toxins?

who quoted gennaro brooks-church who quoted Clarke O'lSen who wrote:
>>
>>> Something I learned the hard way: if you lap glass panels, water 
>>> will
>> capilery back into the joint. If you want to make it tight, maybe a 
>> bead of clear silicone.
>>> Another hard lesson, the amazing power of that caulk not to let go 
>>> when
>> you need to take something apart.
>>> Maybe temporary window caulk would be easier to deal with.

Years ago there was a peelable caulking that was intended for interior use
by folks wanting to seal up their leaky windows for winter and then remove
that caulking when warmer weather came around so that they could open those
windows again.

I remember that stuff steenking to low hades, off-gassing some sort of
petroleum-based solvent.

Aside from the nauseating odour, the "caulk" strategy is a one-off
proposition. You need to apply new (and steenky) caulk every time you want
to move from operable to non-operable modes.

A better approach IMO would be to design to allow for the use of re-useable
gaskets which in the case of this overhead glazing discussion would mean the
stock neoprene (*not* PVC)  glazing channel that is made for use with the
single-glazed tempered glass used in patio storm doors.

The inside surface of the channel gets clamped tightly against the surface
of the glass to create an air-tight/waterproof seal and the outside of the
channel has a series of small ribs which prevent capillary action from
occuring between the gasket and the clamping surfaces while at the same time
providing a protective cushion for the Achilles Heel edge of the tempered
glass.

I would take issue with BCJohn's argument against using reclaimed wood on
the basis that *all* of its cells are susceptible to contamination from
preservative treatments and/or environmental fallout.

I have a hard time believing that any brushed-on or sprayed-on preservative
treatment penetrating to any significant depth would not be removed by the
planing process that most users of reclaimed timber would undergo for finish
work.

The standard for the pressure treating industry for preservative penetration
was (decades ago when I last looked) something like 3/16" for
PS-1 grade treated lumber -- the stuff intended for use above grade for
decks etc ... and 3/8" for PS-1/PWF grade treated lumber  -- the grade that
must be used for pressure-treated wood foundations.

If you've ever been to a wood pressure-treating facility, you'll have seen
that achieving 3/8" preservative penetration depth is no easy task. They
first have to kiln-dry the lumber to render the cells of the lumber amenable
to accepting the preservative and then they have to poke a bunch of slits
into the surfaces of the material so that the preservative can get in and
then they still have to pressure cook it to force the preservative into
those slits.

I don't think that designing for ease of re-use at the end of the service
life of a building  is all that difficult. In most cases it simply a matter
of getting out of the nails and adhesive glop mentality of putting things
together in bits and pieces and thinking more in terms of "systems"  
... not unlike how commercial buildings are put together.

--
=== * ===
Rob Tom					AOD257
Kanata, Ontario, Canada

< A r c h i L o g i c  at  Y a h o o  dot  c a  > (manually winnow the chaff
from my edress if you hit "reply")

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