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Re: WOOD AND HOUSES

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>Date: Tue, 25 Aug 1998 13:15:16 +1200 (NZST)
>From: Bruce Shephard <bruce.shephard(--nospam--at)opus.co.nz>
>To: seaint(--nospam--at)seaint.org
>Subject: Re: WOOD AND HOUSES
>Reply-To:seaint(--nospam--at)seaint.org

The mechanical engineer likely refered to concrete masonry blocks 
instead of bricks.  Clay is a rare find in Florida (other than in the 
Panhandle). 

As far as I know, ALL the Roman (and Moslem) inspired building codes, 
rule out the use of wood for permanent structures. For multiple reasons, 
beyond the scope of my contribution. Even in China they preper petrous 
materials over rice by-product materials.  

Unfortunately, the use of masonry needs special treatment in eatthquake 
prone zones.  Steel can carefully replace masonry, but never wood iun 
Roman inspired Building Codes.


Have you ever browsed a fire code in a Roman system country??? It is 
only a few pages long, compared to the multiple volumes of NFPA codes in 
the US.

Simple. In Roman codes, combustible materials are RARE.

Uplift is another word I rarely heard in my practice in Roman countries. 
If you have a roof slab 4" (100 mm) thick that is 48+ PSF. The net 
uplift under extreme winds for low rise buildings in the Caribbean area, 
is not much more than 48 PSF. 

For a high-rise 32 stories for instance, it can reach 300 PSF!!!! But an 
8" (200 mm)  slab provides a self weight of 96 PSF. The net uplift is 
around 200 PSF. You just supply steel to account for it.

One of my main reasons to move from Canada to the US, was that nearly 
every affordable building was built out of wood. Today I can afford to 
live in a concrete hi-rise structure.  I love noise,  carbon (ollin for 
those who understand spanish) and people.  I am really tired of living 
among cows, wood, and having to travel to downtown for work. Just 
because after 1965, the americans decided to abandon urban life!

I AM VERY URBAN! And proud of it. Have you ever wondered why the roman 
coliseum is still there? Or perhaps the house where Pilatus was born 
more than 2000 years ago is still there?? Many other important buildings 
have lasted2 milleniums or close to it, just because they were not built 
in wood. By the way, some ancient roof structures were made out of wood.  
How come most of these ancient roofs have little or no leaks??  Is the 
english-american system of bio-degradable materials any better than the 
Roman system??? NO!

Jose Diez P.E.  FL.



>I reply to the posting:
>--------------------------------
>> Date: Thu, 30 Jul 1998 18:41:22 -0700
>> From: Juan Enrique Justo <jjusto(--nospam--at)copime.org.ar>
>> Subject: WOOD AND HOUSES
>> To: seaint(--nospam--at)seaint.org
>
>
>> The several posts (and counter posts) I read about the use of wood 
in=
> 
>> houses construction moved me to ask you what follows.
>> Although I=92m mechanical engineer, I do love wood, and my hobby is 
>> woodworking.
>
>Wood is a beautiful material, especially for furniture and interior 
>finishes.  It is also a good construction material as slender 
sections,=
> glu-
>laminated sections, and in veneer sheet forms.  It is also the basis 
of=
> 
>various fibreboards.  It requires special design considerations as 
expe=
>cted 
>for a material comprising natural fibres formed as a moist composite.  
=
>
>Engineering skills are required either directly or in formulating non-
>specific design criteria.
>
>> But I am not convinced -so far- about the benefits of house 
construct=
>ion 
>> from wood which seems to be the rule in USA. Here in south america 
we=
> 
>> still prefer bricks.
>
>Are wood (or timber as we refer to the material in New Zealand), 
suppli=
>es 
>readily available and economic for house construction in South America 
=
>
>though?
>
>> I was in Houston for 18 month, and I had the chance to see the 
progre=
>ssive
>> construction of a condo nearby my place. I saw those tiny (o let=92s 
=
>say 
>> slender) timber pieces to be put together to form the structure of 
wa=
>lls,
>> frames, beams, etc.
>
>The slender timber pieces are joined by nails and fixings, taken 
togeth=
>er 
>with sheet lining and cladding, that make up structural elements that 
i=
>n 
>turn make up a house that is weather tight, load carrying and able to 
r=
>esist 
>earthquake and wind forces.  The structural performance essence is in 
t=
>he 
>energy absorbtion and ductile characteristics of the fixing systems 
tha=
>t are 
>designed to deform before the wood elements become over stressed.
>
>> I also was told (pls tell me if this is true) that 
>> these slim timbers came from very fast growing trees, specially 
devel=
>oped
>> for construction.
>
>Yes,  in New Zealand, the land of fertile soils, sunshine and rain, 
thi=
>s is 
>very true.
>
>> I also was told that unless termites choose the same 
>> home as you do, this full wood houses can last up to 30 years.
>
>NZ is fortunate not to have termites.  Wood is treated to resist other 
=
>
>insect infestations, and chemically treated for wet and soil contact 
>conditions.
>
>> All this introduction is just to ask to you fellows (ladys included) 
=
>why
>> this wood based system was chosen. Are there some kind of historical 
=
>
>> reasons?, or may be old traditions? A friend that lives in Tampa Fl, 
=
>made
>> his house to be built up in our traditional way (bricks and more 
bric=
>ks)
>> and he had to pay 30% more that a fully wood house. So, Is it 
because=
> of
>> money?
>
>Partly historical tradition and partly money or economics in NZ.  
Europ=
>ean 
>settlers arriving in the early 19th century and developing farmlands 
fo=
>und 
>vast native forests and so built in wood.  When gold was discovered 
man=
>y 
>towns and cities were constructed in masonry brick.  There are good 
cla=
>y 
>deposits for brick making.  Strong earthquakes in the late 1800's and 
e=
>arly 
>1900's clearly showed that wood buildings performed better than the 
bri=
>ck 
>ones,  so -----
>
>Currently most single family houses are constructed in wood.  They are 
=
>
>painted (for durability) in many colours and this sets the NZ urban 
cit=
>y 
>scape apart from many overseas,   even more colourful than the west 
coa=
>st 
>US.  We have both light weight (steel/iron) roofs (again in many 
colour=
>s)and 
>heavy weight roofs (clay or concrete tiles).  We also use a masonry 
ven=
>eer 
>to wood framed, with interior linings, houses so that they look like 
>masonry.
>
>Many 2, 3 and 4 storey commercial buildings are constructed in wood, 
>particularly those more than 60 years old in smaller towns.  NZ also 
ha=
>s 
>good natural materials available for reinforced concrete construction 
a=
>nd 
>this is the common form for larger buildings.  Light steel sections 
are=
> used 
>for industrial buildings.  Larger steel sections have to be imported, 
s=
>o 
>only the highest commercial buildings feature steel frames.
>
>Our houses and buildings designed to current standards are expected to 
=
>have 
>good earthquake and wind resistant performance.  Earthquake as good as 
=
>for 
>California.  Wind to hurricane levels!
>
>> By the way, how about New Zealand? What do you use there?
>
>As above.
>
>> 
>> Finally, I would like to tell you that this query is just for the 
sak=
>e of
>> knowledge.
>> 
>> thanks
>> 
>
>There's a short history of wood construction in New Zealand.  I hope 
th=
>at it 
>is of general interest.
>
>Cheers,  Bruce S
>
>--------------------------------------------------
>Bruce Shephard, Principal Consultant Seismic Risk
>Opus International Consultants, New Zealand
>DD Telephone +64 4 4717597,  Fax +64 4 4711397
>Email bruce.shephard(--nospam--at)opus.co.nz
>--------------------------------------------------
>
>
>


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