Re: Metal Roofing (& unrelated stucco info)

[duckchow@ix.netcom.com]

At 10:46 AM 1/29/97 +0000, Robin Rierdan wrote:
>I too am interested in this metal roofing discussion, so, fi you have 
>info as to the questions being posed , post to the whole list instead of 
>privately. Thanks r2

	In addition to the current thread, anybody interested in the metal roof
topic should also search the archives for previous extensive threads
covering condensation, types, installation, etc...

Solstice/CREST Keyword Search
This engine will search the entire Solstice database, including the full
text (NOT just the message Subject Lines) of the Strawbale Archives. An
incredibly handy tool.
http://solstice.crest.org/common/search-me.html

	There have also been extensive threads on other newsgroups about metal
roofing; try one of the Usenet-inclusive search engines to dig up other
posts from other sources containing first-hand info as well.

*

	Generally (speaking here WRT responding via email or to the list) if a
response contains info which would likely be helpful in a general sense to
more people than just the person who asked about it, it's a nice thing to
post it to the list. OTOH, if it's a personal matter and not generally
beneficial, take it to email or a chat room.

*

	After reading Robin's plea up there, I'm feelin' a little guilty about an
email I sent the other day which may (or may not) contain helpful info
about cement stucco particularly and stuccoing generally. I don't think
there's much in it that doesn't already appear in the archives, but I could
be wrong. (Sometimes I forget where I get my info...)

*

	... The general pearls I do recall are several... I'll write as I remember:

	It's been suggested that the bales, especially if very dry, should
actually be hosed a little before the first coat of stucco to prevent the
wet stucco's moisture from getting sucked into the straw too much and away
from the stucco mix, thereby weakening it. OTOH, *too* much moisture in the
mix is equally bad whether it's mixed that way or from rain immediately
after application, etc. Keeping the new stucco application moistened (not
soaked) for a few days is of paramount importance. Searing dry summer heat
makes for difficulty, it dries out the stucco too quickly after it's
applied. Moisten (mist) the stucco frequently as it's curing for some days.
Covering with plastic helps keep the moisture in during the cure. The
stucco will "harden" within a relatively short amount of time, but
hydration - the real process contributing to actual hardness,
effectiveness, and longevity - continues for at least a month (ideally).
[As I understand it, lime-based stuccos are another thing as regards
hydration.] When applying a second or third coat, the previous coat
(assuming the initial set is complete) should be misted beforehand and have
a darkened appearance. I've heard a couple schools of thought about
SB-stucco time-between-coats... the first says that a month minimum should
go by between the first and second coats, with the third coat up to a year
later; a second says that successive coats should be done on successive
days. A combination of those says that the first and second coats should be
applied on successive days (so they bond well, I'm told), and the finish
coat after the initial coats hydrate fully. That way the finish coat could
be relied on the take care of any hairline cracking, etc., in the previous
coats. [A source quoted below decries the practice of "doubling coats" ...
*research*!]

	As to seasonal timing, I'd think anytime that's not too hot and dry [or
cold or wet] would be good; anytime after frost danger has passed, but
probably as soon before summer as possible. The finish coat, if you chose
to let the preceding coats totally hydrate, could go on in the fall.
Personally, I'm finding myself tempted to wait for a cooperative spell of
fall weather a few weeks before hard frost for the first two coats; then
applying the finish coat the following spring.

	Now that I've filled your head fulla crap, I'll get out a couple
legitimate references.

	From "The Mason's Toolbox Manual" by David Tenenbaum (Arco/Simon &
Schuster, 1990... page 200) -
	Moist curing is needed to develop a strong plaster coat. In cold
conditions, use practices recommended for cold weather masonry. ANSI
Specification A42.2 calls for curing in an enclosure kept at 40F for 48
hours before and after application.
In normal weather, cover the work with plastic for 48 hours. In hot
weather, use tarpaulins or plywood barriers to reflect sunlight and keep
the plaster cool. Fine mists of water can be substituted for the plastic
covering during hot weather. Fog spray is best if continuously applied
during the curing period.

	From "The Complete Concrete, Masonry, and Brick Handbook" by J. T. Adams
(Arco, 1979... pages 504 & 505) -
	Suction is absolutely necessary in order to get the proper bond of stucco
... Obtain uniform suction by dampening, but not soaking, the wall evenly
before applying the stucco. If the surface becomes dry in spots, dampen
these areas again to restore uniform suction ... Work on the shady side of
buildings when possible, for it is hard to keep walls damp when they are
exposed to the sun ...
	To develop maximum strength and density, it is necessary to cure portland
cement stucco properly. Keep brown and finish coats damp continuously for
at least two days. [In the book, the preceding sentence is italicized.]
Begin moistening each coat as soon as the stucco has hardened sufficiently
not to be injured, applying the water in a fine fog spray. Avoid soaking
the wall. Give it only as much water as will be readily absorbed. To
prevent excessive evaporation in hot, dry weather, hang tarpaulins over the
outside.
	After the damp-curing period, allow the stucco coat to dry thoroughly
before the next is applied. The practice of doubling coats is not a good
construction practice.
When stucco is applied during cold weather, longer curing periods are
necessary. In freezing weather, do not apply stucco unless special methods
are employed to keep the materials at a temperature above 50F (10C) for at
least 48 hours.

>From "Use of Concrete on the Farm" (Farmer's Bulletin No. 2203, U.S.
Department of Agriculture, 1965... page 15) -
	[Ah, skip it. Same stuff as up there. Too hot bad, too cold bad. Keep moist.]

>From "Construction Manual: Concrete & Formwork" by T. W. Love (Craftsman
Book Company Of America, 1973... snips from Chapter 18, titled "Effects of
Temperature") -
	... During hot weather, precautions should be taken to limit concrete
temperature to less than 90F... The combination of hot, dry weather and
high winds is most severe... In hot weather the tendency for cracks to form
is increased both before and after the hardening... For successful winter
work, adequate protection must be provided when temperatures of 40F or
lower occur during placing and during the early curing period... Concrete
that is allowed to freeze soon after placing is permanently damaged. If the
concrete has been frozen once at an early age, it may be restored to nearly
normal under favorable curing conditions although it will not weather as
well nor be as watertight... [charts, graphs]...