are concrete "bloques" earthquake/hurricane resistent?

I depends on the engineering of the buiding, the amount and type of cement and the amount or rebar used.
If all is correct then the buildings do well in hurricanes and earthquakes (depending of course on strength)

Bob K

CBS construction has peu a peu become CODE in DADE, then Broward and Palm Beach counties, Florida.
Still, in Florida, homes will blow up once the storm make it's way into the house, lifts the wooden roof off and blows up the walls.

This is UNLIKELY to happen with "good" Dominican construction because of the concerns about earthquakes.
Dominican concrete block structures use the blocks basically only as "fillers" in between a structure of entirely interconnected poured concrete pillars and beams. In other words, the home could virtually stand without the blocks (in some other Latin American countries, that's exactly what they do... they pour the framework of concrete columns and beams FIRST and then fill with bricks or blocks). The rebar coming out of the upper "belt" of beams connects into the poured on concrete roof.
Additionally, many of the inner walls are equally framed CONNECTED supporting/ankering walls.

If storm winds WOULD happen to make their way into such a home, thru an open door or shattered window, following the rules of least resistance, it will find a better exit than lifting off a concrete roof... it'll move some stuff around and something will break an exit window. But that's about it.

Sadly Florida home are missing even only the top poured concrete "belt" beam which goes ALL around AND across the whole structures, effectively HOLDING it together... not to speak of concrete roofs. :bored:

There is virtually NO total protection against earthquakes, but following the rules of physics, making NO shortcuts in beams and supporting pillars and materials (cement and rebar). Generally, well built and maintained wooden structures are those which tend to show less damage and kill or injure less of it's inhabitants in case of an earthquake.
Another thing I ALWAYS stress but seem to hit only def ears is, that IF YOU build, DEMAND and INSIST on a humidity barrier being applied in between the ground and your home. Humidity working itself into the bottom part of your home slowly DETERIORATES your home and adversely affects it's structural soundness.



... J-D.

J D Sauser said:

Another thing I ALWAYS stress but seem to hit only def ears is, that IF YOU build, DEMAND and INSIST on a humidity barrier being applied in between the ground and your home. Humidity working itself into the bottom part of your home slowly DETERIORATES your home and adversely affects it's structural soundness.



... J-D.

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EXCELLENT advice.

We build Mom CB a nice CBS home in FL.

Before the slab was poured, the contractors laid down a thick plastic barrier on the termite-treated compacted dirt (well, sand in Tampa), and squirted a plastic sealing agent along the sides and electrical/plumbing/gas conduit sticking up. This was for both moisture and subterraniam termites. Only then was the slab poured.

Edwin:
the La Romana area is not known for earthquakes.

Hurricanes are something else! However, La Estancia is somewhat inland, and therefore a bit protected. Good construction should be sufficient to withstand all but a Cat 4 or 5 Hurricane...This is something you local civil engineer can acertain.

HB

It is a sad fact that the use of hurricane resistant construction (buildings with poured concrete roofs) without the proper earthquake resistance of adequate and properly placed rebar, was one of the main reasons the death toll was so high in Haiti for an earthquake which was not really that strong. Most of the victims were crushed by the heavy concrete roof falling on them when the unreinforced (or inadequately reinforced) block walls supporting them collapsed. Relatively few died in structures with tin or thatched roofs. Ironically, most of the people living in houses with concrete roofs were more well to do, and thought they were safer with a concrete roof overhead.

edwin valencia said:

...
There are some pictures from the beginning of construction where I think I see these
"interconnected poured concrete pillars and beams" J.D. was mentioning.
....
cheers/edwin

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Edvin, if your last name here (Valencia) is to suggest you are from the Spanish Valencian region, well, have you seen homes being erected in the Elche region? There they first pour a framework of concrete beams and columns and then fill it with blocks. HERE, it's the same, just that the process is backwards (simpler to do) as they raise the block walls with open spaces for the columns first and THEN pour the concrete into these spaces and a concrete "BELT" (in Spain they call that un "suncho") on top:

edwin valencia said:

Thanks J.D.,
And yes, I am a Dutch guy married with a Spanish lady and living with our 2 kids for the last +20 years in a small village on the cost of the Castellon province, which as you probably know is part of the comunidad valenciana.
our plan is to live at least a couple of months per year in La Estancia when our kids grow up and go their way.
for this reason I try to be updated on the DR through this forum but unfortunatly I can not be on top of construction of out condo which is taking 3 years.
for what I see they did use the beams as you showed in your pictures, and hopefully did the moisture barrier as well.
Even in spain where where we had a house constructed 10 years ago and spanish brother in law being the architect, they forgot to put "juntas de dilatacion" separating our terrace and patio from the house which has made our walls and terrace floor crack, and forgot to put the the moisture barrier up to the end against the skirting of some doorways so as you say paint will chip and stay wet there for the rest of our lives.

did you live in Elche before you moved to the DR?

cheers/edwin

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Edwin.
I lived in the Comunidad Valenciana, yes. But not in Elche. I have been mostly around Javea and region. I have built homes there, the last one being
Finca-San-Miguel | Parcent | Costa Blanca



If you HOPE "they" put a humidity barrier into a home here... your hope is with 99% probability a waste of time. Here, the few who would know about that "technology" refuse to accept it's necessity.

I have described more issues to watch out for, which may help you better understand how they build here in this article:

A general manual on what to consider and observe when building in the DR

Thanks! ... J-D.

Homes in the US are typically wood frame with a wood, block or brick exterior. In Florida concrete block is more prevalent due to termites, however the roof trusses are wood.

Supposedly the newer homes are designed to withstand hurricane force winds but the loder ones maybe 20 years old or so not so. Also, too relatively new technology has enabled the roofs to be attached much stronger than 20 or 25 years ago as back then they only used nails.

Homes here in the DR are much stronger when built correctly typically because the lack of economical wood for construction.

Chip said:

Homes in the US are typically wood frame with a wood, block or brick exterior. In Florida concrete block is more prevalent due to termites, however the roof trusses are wood.

Supposedly the newer homes are designed to withstand hurricane force winds but the loder ones maybe 20 years old or so not so. Also, too relatively new technology has enabled the roofs to be attached much stronger than 20 or 25 years ago as back then they only used nails.

Homes here in the DR are much stronger when built correctly typically because the lack of economical wood for construction.

Click to expand...

True.

In fact, after the building code changes from Andrew, you could see which homes were built to code following the FL hurricane blitz of 2004. Those built to code stood largely intact. Those built before code got hammered.

edwin valencia said:

So what you are saying it's more of a money thing the fact in the US wood is used?
what about the cost of your home being blown away every couple of years?
I suposse insurance companies have that in mind.

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Money has its part but as was mentioned above if built to code, they will withstand a Hurricane. If not well??
you needed a different builder, or sue whoever done the inspections.

the advice on how should be built is great, and makes sense...

nevertheless they are building a new house here down the street, so I was able to follow it up quite closely...

instead of pouring the concrete pillars first, and then filling them up with the cbs, they did it the other way round, which looked strange to me...

of course no humidity barrier either...

In Belgium they do indeed put a sort of rubber on the dirt before they put the bottom slab up, but they also put a rubber layer between the bricks of all walls, at about 10 inches above the foundations to prevent moisture from rising (obligatory by the way)..

We have built a number of houses in Belgium, and as most houses are completely made of brick, the concrete pillars do not come into the pic...

Best house we ever built was made of ytong blocks... a sort of material which has superior insulation qualities, weighs next to nothing, and builds very fast... the blocks are glued together...

belgiank said:

the advice on how should be built is great, and makes sense...

nevertheless they are building a new house here down the street, so I was able to follow it up quite closely...

instead of pouring the concrete pillars first, and then filling them up with the cbs, they did it the other way round, which looked strange to me...

of course no humidity barrier either...

In Belgium they do indeed put a sort of rubber on the dirt before they put the bottom slab up, but they also put a rubber layer between the bricks of all walls, at about 10 inches above the foundations to prevent moisture from rising (obligatory by the way)..

We have built a number of houses in Belgium, and as most houses are completely made of brick, the concrete pillars do not come into the pic...

Best house we ever built was made of ytong blocks... a sort of material which has superior insulation qualities, weighs next to nothing, and builds very fast... the blocks are glued together...

Click to expand...

Raising the concrete block walls FIRST, while leaving spaces for the concrete column and beam frame to be poured later is common practice here and quite OK.

What is not, is to bury the footers (foundations) deep into the ground and then just build up with concrete blocks WITHOUT adding a humidity barrier and girth beam a little above ground.

But they won't believe that.

<hr>

Florida:

Older buildings in SE Florida will still be wood or part wood or only the ground floor in concrete and the rest... wood.
As CB stated, it took Hurricane Andrews to finally compel building authorities in first Dade (Miami), and only even later Broward (Fort Lauderdale) and Palm Beach counties to issue a GRADUAL change of building ordnances (codes). First, the ground floor had to be CBS, then only later, after this proved to provide little comprehensive protection, all three counties have subsequently upgraded these building codes to a mandatory ALL CBS construction for housing.
Still, it only provides VERY LIMITED protection, compared to what is commonly done here, as in Florida, roofs are still wood and most CBS homes LACK a top poured girth beam which holds the walls together should wind make it's way into the dwelling and lift off the roof (something I have no knowledge that ever happened with a poured concrete roof here).

So, enjoy hurricane safe housing in the DR!
Just stay clear of rivers and their proximity, ALL the concrete of the world does not protect against flash floods.


... J-D.

J D Sauser said:

Still, it only provides VERY LIMITED protection, compared to what is commonly done here, as in Florida, roofs are still wood and most CBS homes LACK a top poured girth beam which holds the walls together should wind make it's way into the dwelling and lift off the roof (something I have no knowledge that ever happened with a poured concrete roof here).

... J-D.

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Now a bunch of fancy anchors are used to keep roofs on, and the work as evidenced by the 4 hurricanes in a row that ripped through Central FL in '04. Few roofs were lost, although some shingles were.

Agree with the last statement, I built as JD noted block walls (8'' external and 6'' partitions) leavint the column with rebar tied into foundation and belt course / column poured in one operation using a concrete placing truck pump and ready mix 35N concrete mix. I decided on a wooden roof structure tied into the beam (Vega)using Simpson hurrican straps and screwed 3/4'' plywood onto the wooden beams at 12"on centre. I made this decision as I did not want problems later with the maintainance of a concrete flat roof etc. The roof has been in place now for 3 years and to date no problems (hopefully to continue). I also screwed the Aluzinc standing seam roof panels to the plywood at 18"centres, trimmiing out around the peremeter so reducing the effect of localized uplift in the event of a strong storm hitting the area.

For love nor money I could not find the Simpson hardware in SD, so shipped down from Miami, maybe someone someday will stock suck items, I know they are readily available in the Bahamas and the smaller islands like St Maarten etc.