OK, why concrete all the way up?

[Headshot 29,349]

Because, "That's how we do it here, Sir."

 

Wood gets eaten by termites to fast, need to use light gauge steel frame with brick veneer.

 

In a lateral earthquake, brick veneer will go through wood or lightweight steel framing like it wasn't even there, collapsing the structure. Rethink that.

Edited October 16, 2013 by Headshot

[Hy H 1,987]

 

 

thebob, on 25 Jul 2013 - 10:46 PM, said: Nice and cool underground, and you could have an almost sound proof bedroom.   Now there's an idea. Concrete part way up, backfill with earth if below grade is an issue.   Any Filipino superstitions about being below ground?

 

Works well on sloping building sites. Just need to make sure prior backfilling, external walls are well waterproofed against any moisture transfer to inside of the walls. Moist, moldy walls are very unhealthy. Paint and tiles will not stick too well. And very costly later on to rectify. Below ground construction on flat ground ? Good for a swimming pool.

[senseless 966]

In a lateral earthquake, brick veneer will go through wood or lightweight steel framing like it wasn't even there, collapsing the structure. Rethink that.

 

http://www.nashnz.org.nz/publications/earthquake_test.pdf

 

You're supposed to anchor the brick veneer to board which is anchored to the steel framing to distribute the load. Steel framing is the best earthquake resistant structure. In every case I've seen where the exterior veneer cracks and falls, it falls outward, not inward.

 

The steel structure in the PDF survived multiple (9) 7.3 magnitude quakes with only minor damage (top 2 rows of bricks fell, and some damage to the plaster board). (2.5 times el centro's 6.9 quake is roughly 7.3 magnitude).

Edited October 16, 2013 by senseless

[SkyMan 23,691]

Regarding block all the way up.  A very nice 2 story home I drive passed to my house was completed about a year ago.  It has a good few cracks now and a 3-4 foot high section of wall along one side above the second floor fell out taking out quite a bit of the soffit.  Looks to me like the builder decided walls above the second floor ceiling were just for show so no rebar required. 

Edited October 16, 2013 by SkyMan

[thebob 18,260]

 

 

The trick is to know how thick of concrete is good enough and how much and what diameter rebar to use.

 

It isn't a trick, it's physics. You need to know the modulus of your materials and calculate accordingly. Strength is designed, it isn't a case of just making everything bigger.

[hchoate 446]

You need to know the modulus of your materials

 

A modulus is a generic term for a constant or a ratio used in conjuction with a physical property- modulus of rupture, tensile modulus etc., etc. Very complicated stuff.

 

The heavier a material is the stronger, which usually means heavier, its structure must be to hold itself up.

 

I just have trouble imagining living 'under' concrete in an earthquake zone- it's heavy and it crumbles (and a concrete box makes a dandy oven).

 

Obviously, a great enough force at the right (wrong) angle will bring anything down. So one factor to consider is what's gonna come down. I doubt anyone's ever been crushed by bamboo and thatch. But that's too light not to blow away.

 

Earthquake and high wind- I'm kinda leaning toward well treated wood, or a synthetic, attached to a steel frame.  Of course, concrete is fire-proof, too ...

Edited October 16, 2013 by hchoate

[Knowdafish 1,772]

 

 

I just have trouble imagining living 'under' concrete in an earthquake zone- it's heavy and it crumbles

 

A poor mix of concrete that has little or incorrect steel reinforcement is the nightmare. If it is made properly (the correct ratio of concrete, sand, and rock to water) it is extremely strong and doesn't "crumble" when properly reinforced with steel. 

 

The problem here is that too many shortcuts are used in order to attempt to save money, which is false economy. Which is cheaper a structure that lasts 100 years or one that doesn't even last 10? 

[hyaku 2,796]

A poor mix of concrete that has little or incorrect steel reinforcement is the nightmare. If it is made properly (the correct ratio of concrete, sand, and rock to water) it is extremely strong and doesn't "crumble" when properly reinforced with steel. 

 

The problem here is that too many shortcuts are used in order to attempt to save money, which is false economy. Which is cheaper a structure that lasts 100 years or one that doesn't even last 10?

 

That's why you need to "be there" when they build. All sorts of trick and cutting corners to save time and money. Ask around and pick the crew. I did what was for my partner the fourth house. I still use one particular mason and carpenter if I have odd jobs.

 

A house near the beach 'will' get built with beach sand if your not there. And its not just directed at foreigners either. Look at the damage in Cebu.

[Davaoeno 37,477]

 

 

A house near the beach 'will' get built with beach sand if your not there. And its not just directed at foreigners either. Look at the damage in Cebu.

 

 

with all that construction its amazing there are any beaches left !!