Engineering question of the day

Cliff wrote in news: snipped-for-privacy@4ax.com:

New or recycled house? Around here it would have been cut in half or built in two bolt-together pieces. The trailer and house held up ok. Would be interesting to see how they got it off. Nice battery of hydraulic rams I guess. "There is an engineering solution to every problem" as long as someone pays ...

In Cape Coral FL awhile back they built a brand new bridge with upramps and all that and in the process moved something like 80 houses to new locations. Concrete block houses complete with concrete slabs, footings, all of it, in one piece. As of 2 years ago some of them were still sitting on trailers in vacant lots waiting to be re-planted. They would move them down the streets early in the morning, 3 am, and yank the overhead power wires, traffic signals, etc. These were houses in the 1500-2500 sf range.

"Don" wrote in news: snipped-for-privacy@news5.newsguy.com:

139 - 232m2 ... some scary weight there - any images available? Heaviest thing that moved around here in recent years was a church, but in three pieces (it had moved before so the same cut lines could be used). A fair amount of heritage stuff gets relocated, mostly hardwood framed and clad. Too expensive to build with the stuff now, and not PC to harvest it. But it stacks up as an example of 'sustainability' in practice - most of the embodied energy being retained for the indefinite future etc.

No pix. They may not be sitting around anymore. I personally wouldn't buy a house like that. In my opinion concrete houses shouldn't be moved.

Why not? Properly moved they should have no damage. About 15 years ago I was the architect for the moving of the Southeast lighthouse on Block Island RI. A brick structure 70' tall with a 2 family brick attached brick structure. Walls of the light were 3' thick at the base. 4' base was granite over brick backup. Originally built in 1870. The 150' bluff it was on had eroded back

200' in 120 years, so we moved it back 250'. We did build a new foundation. It was moved on rails in one piece, with no cracks.Here is the whole history: EDS

I hope you guys took pictures of it moving.

"EDS" wrote in news:Y_idnbsu89DaMSDanZ2dnUVZ snipped-for-privacy@comcast.com:

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Oh! Hmm, so what is the cost of, say, two of those 11'X30' precast units, compared with the cost of a similarly-sized one storey house structure (not lal the plumbing etc), IOW, what I'm wonering is whetehr it'd be economical to put up dwellings in a similar way?

And IIRC, if you use native North American wisteria, it doesn't get as crazy-huge as does the common CHinese wisteria

Seriously...? I've lived in low-rises, where the walls are pretty much just regular hosue-type walls, and you could hear *everything*, including, er, bathroom functions. You could also *smell* everything, which is bad when the neighbors' place reek slike rotting garbage. It was *maddening* - one of those things that makes you understand why people start shooting off guns... It seems to me that concrete would be much quieter. ALso, why not put up a few studs on each side fo the concrete, throw in some insulation, and cover with sheetrock? Sheetrock has to be put up anyway, doesn't it?

It makes me wonder why that method is so rare. Isther eless stability, strength, or longevity? I'm curious about this. It *seems* like there would be a great amny advantages to modular building, so all I can think is that it must be as expensive as all hell...

I like the Chinese Wisteria. In Boston we had a really ugly fire escape on the front of the house, so I planted a Wisteria. Within 5 years it had climbed to the roof, 4 stories above, and formed a complete cover for the house front. My kids hacked out a "wisteria house" outside the top floor windows on the top F.E. platform and spied upon and dropped water bombs on their friends. When we remodeled 10 years later, we found that the wisteria had bent the steel F.E. supports. I presently have a wisteria that covers my porch each summer.

The projects I mentioned just painted the concrete, as wallboarding would have added costs. In the 60's nobody talked about insulation. These were HUD

221d3 blocks and gov't recommended insulation was none in the walls and 1" Styrofoam on the roof. The exterior walls had condensate on them in the winter and ice in the hallways. Cost for each apt. could not to exceed $14,500, or about $20 per square foot. Concrete is quieter, but impact (such as high heels on floors) comes right through. Hell to hang pictures on also ;-) Don is right, the road to Hell is paved with good government intentions. EDS

"EDS" wrote in news:-ZadneP_QaP9eyDanZ2dnUVZ snipped-for-privacy@comcast.com:

Each has their uses. Sometimes, a smaller one is appropriate. Also, WIsteria can go truely rampant in a mild climate... I don't recall how they climb - some tendrils can invade morter, and some vines (IIRC, Trumpet Vine is one) also have sucker-like things that seem to create a sort of "glue".

So you have to check the moreter etc. to be sure that you have your structural integrity intact. I don't recall how long all of this takes; jsut tht it's a possiblity that makes checking a good idea.

They do smell great, tho' ;)

THat's true. OTOH, could it be retrofitted...?

True, bare bones like that wouldn't work well at all...

Wisteria climb by wrapping tendrils around trees, fencing, fire escapes, etc. They do grow fast, do not damage masonry. EDS

"EDS" wrote in news:2LydnXpRsqgFkiPanZ2dnUVZ snipped-for-privacy@comcast.com:

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Ah, I see, I'm not that familiar with them so I didn't know. I remember, when I lived in Columbia, SC many years back, seeing them covering phone poles and going across teh wires to travel back down trees, and so on - there was one street in particular that was just loaded with them, and when they were in bloom, it smelled great :)

IIRC, there is a black locust (or some sort of locust) that grows fast, does not sucker or have thorns, and also have a wonderful scent; had one growing outside of a 2nd storey apt window in Canada.

Still wondering, tho', about the whole modular concrete house thing. It seems practical from the standpoint of being termite-proof (a biggie down here) and rot proof (another biggie), but would it be practical and economical?

We used to dream of extruding concrete houses, but there are some problems:

-To be accurate and be able to piece the thing together, skilled workers must be used, not the wood knockers used in prefab buildings.

-Weight. Heavy equipment and cranes are needed.

-Public attitude. I designed a large car wash / lube / detailing building that is just getting completed. We used a Canadian system (Royal Building System) that has permanent PVC forms that lock together and hold the reinforcing in place. The forms are grouted solid to produce an 8" or 6" solid wall. In our case, we applied a minimum 2" EIFS insulation/stucco facing on the outside. All interior areas are a smooth white PVC finish. This system is much easier to manipulate and frankly looks a lot better. EDS

"EDS" wrote in news:oZCdnV-S8tbXgiPanZ2dnUVZ snipped-for-privacy@comcast.com:

SO, being rare, it'd be impossibly expensive, I guess. :(

THat sounds practical - just out of curiosity, how is it on the "green" scale? COme to think of it, is concrete more or less "green" than wood products (taking into consideration things such as maintenance and longevity)?

((Heh, my dream, a house I could just hose down on the inside ))

Why do you think we used it for a car wash? Concrete is not very green. Lots of energy used to produce Portland cement. Concrete is not very recyclable. Steel is actually quite green as most of it is recycled and many times can be reused. Wood is OK as it can be replaced and often can be reused. The greenest is to live in an old house;-) EDS

"EDS" wrote in news:a4qdnZONi5H5lCLanZ2dnUVZ snipped-for-privacy@comcast.com:

Good to know re: concrete, thanks for the info!

Consider the precast concrete Roman foundations and earthworks including pipes over two millenia old . However green, longevity counts as you are not wasting through replacing.

Normal concrete will not hold up as well. The Roman concrete was made with Pozzolanic (volcanic) sand from Vesuvius that is molecularly different than normal sand. I'm no chemist, but as I remember it bonds on the molecular level with slaked lime to form a waterproof concrete. This concrete also sets up under water. Here in Boston the Big Dig and several deep parking garages adjacent to the harbor have used slurry walls made of this material rough poured down to over 60' below sea level and reinforced with wide flange steel sections. (Yeah I know the Big Dig leaks, but its not the slurry walls, but the stuff drilled through them and the crappy design by Bechtel.) EDS