If you like construction and want to check out what I’m inspecting right now, you will find interesting posts below.

NOVEMBER 2013: FLOATING SLAB IN PUERTO VIEJO, LIMON

Underwater lies a 15 centimeter floating concrete slab with 12 concrete pedestal, where wooden column connections start.

NOVEMBER 2013: PREFAB CONCRETE IN SANTA ANA

2013-11-19 14.06.57

Load bearing walls for a prefab concrete 2 apartment dwelling

MAY 2011: METAL WORK AT SILVIA´S APARTMENTS IN HEREDIA

Since our beams were ready to be placed over the plates, our primary structure gets built really fast. This picture shows a 2 day work.

MAY 2011:FOOTINGS AT SILVIA´S APARTMENTS IN HEREDIA

This is the metal plate that makes the connection between 4¨ x 4¨ sections that work as columns and the concrete plates. Bent rods go the other way around.

Single plates at Axis #3. Just next to where the future tire retaining wall is going to be.

One of the plates, just before being poured. Rings are 45 centimeters by 45 centimeters and concrete plate is 1 meter by 1 meter.

Detail of plate in Construction Documents

APRIL 2011:EXCAVATION CONTINUES..

SILVIA´S APARTMENTS

After 2 weeks (with heavy rains included) our terrain is almost ready to start putting tires as retaining wall. The main slope which tires go against to, is covered with plastic to protect it from an eventual erosion.

We found some rocks 5 meters deep. We are close to a river, maybe that´s why. We will remove it and continue digging.

Simultaneously, Zacarias the builder, is welding all the beams needed for the project at his workshop. This is very benefital for the project, logistics are important during a fast track project process.

Special ¨minio¨ or lead paint is been used to cover all metal. Three layers are needed, and it is extremely important to apply them with a roller. This way the material is applied evenly all over the sections.Red lead paint stops oxidation of iron and steel.

APRIL 2011: ANOTHER PROJECT STARTS.

EXCAVATION AND METAL WORK AT SILVIA´S APARTMENTS

First day of work. We need to remove about 450 cubic meters in such a small area. Maybe our neighbor will let us put some of the material on his lot, so we do not have to hire transportation. All done by 4 guys by hand.

We defined three main levels of excavation to work on them: first level to substitute with tires, second level for footprint base and third level for the lowest footprint base of the project.

Can you believe all this trash was holding up the existing slope? Be ready for the unexpected always, let´s get rid of that garbage and do things right!

AUGUST 2010:WOOD AND MORE

SITE INSPECTION AT POAS VOLCANO CHALET

Here you can appreciate how connections between wood sections are made. Specified screws support loads when all the sections work together as a beam.If you want to know more about wood, I suggest you check out my article on wood. Click here

This is the sample for the wooden beams provided by the sub contractor in charge for this project. These sections were assembled on their workshop, they were also treated there. Now all that the builder needs to do is locate this beam with a crane on it’s exact position. This beam is composed of t 2 x 8″ teak sections, and screws were determined by our structural engineer.

Wood section showing the tree’s rings. The cut has been perfectly done.

This is how we are going to connect our sections between them. It is going to be a specified leveled metal plate connector. It is not going to be located following the beam pitch. This is the correct way to do this kind of connection

90% Completion

AUGUST 2010: PLASTER WORK CONTINUED
SITE INSPECTION AT POAS VOLCANO CHALETGeneral view of the house after 5 months. Man power has been reduced at this point due to final structural work. Now they are working on outside wall finishes. In this picture, the main access arises.

We have started to break ground on the second phase of the house: a small guest house that will hold 16 people. A very fun functional space was designed just next to the house, in order to hold more people in a more informal way. This will be where kids and teenagers…( and adults who wan to have fun) will be able to share a a playful space: 2 stories connected by a a firefighters pole.

Metal work is something that I really like. It’s flexibility, durability and sustainability allows to work faster. The deck in this case , has a metal structure held by the concrete beam, where a plate was previously located. Metal beams come out of this plate, welded.
Here we have a space left for window frames, so you won’t step on them, they are leveled with the floor, so no accidents will happen when one is drinking wine and wants to come out to the terrace!

This is the chimney structure. Soon it will be poured.

Probably in 3 weeks, we will have the wood beams screwed with the help of  metal plates that rest over the concrete beams. That slab will recollect all the rain water.

Right now, all the man power is concentrated on electrical and mechanical lines and outdoor block wall finishes.
Till next week. Excited to see if the contractor brings a big  wood truss sample!

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AUGUST 2010:MORE ABOUT STEEL FRAME CONSTRUCTION

SITE INSPECTION AT POAS VOLCANO CHALET

Metal work has fully started! For this side of the house, the deck, we decided to have a lighter structure that will support one of the most beautiful features of the house. From here you are able to see all the Central Valley, even our new stadium! Our columns are 4″ x 4″ metal sections every other 3.5 meters and they are designed to support a cantilevered deck of 2 meters.

Our beams would be also 4″ x 4″ inches sections, but the ones that support the wood deck itself, have a stronger caliber of 2.4 mm. The rest of the sections are 1.8 mm and are what is called ” tubo estructural” which is a strong squared or rectangular section that comes with no finish. Steel  is a metal that oxidizes easily by the action of the humidity, forming little by little a hydrous oxide film that debilitates the iron. In marine beaches also the oxidation is easy, due to the air iodado and and the saline emanations, that also attack it oxidizing it. The metals are protected of the oxidation covering them with paintings, galvanized, covered with lead, tin-plated, enameled and with concrete.
In this case, what’s suggested on the blueprints is to use one layer of zinc chromate or iron monium and 2 layers of finish with different colors.
The differences of colors is a strategy that will help the inspector, to check that each layer is applied correctly. It would be easy to note with the difference of color that one of the layers has not enough product .
Previous to the protective processing, the metal must perfectly be cleaned, in order to obtain a better adhesion. For it is possible to be dealt under pressure with a fine grit blasting, past brushes of steel by hand or to machine, or with  chemical reagents, like  phosphoric acid, that provides the industry under the name with liquid rust-remover.

Once the surfaces are clean, you should apply a base layer of antioxide that can be zinc chromate, 50 micras is the correct quantity. When it’s dry, then you’re ready two apply 2 finish enamel layers, 25 micras each layer.That yellow color you see on the structure is the base.

Another important aspect of metal is the welder’s work. A welding has be to of good quality

Metal Columns are already standing
Unions between beams and columns, welded.
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JULY 2010:BLOCK WALLS

SITE INSPECTION AT POAS VOLCANO CHALET

Complete view of the house from above.
Almost ready to pour beams and concrete slab.

Main access to the house.  A concrete slab goes over this vestibule, pretty much like our vernacular houses back from the 70´s, where you used to have very thin slabs projecting themselves into the air.

Adequate propping for a window. V form. Depending on how long the window is, you might need more wood posts as a support. Since there´s a beam over it, that´s why it haven´t been poured.

Simple support for a small window.

Adequate support for a concrete beam. This time, we are using steel behind additional wood bars under an important beam, due to it´s dimensions.

Beam ready to be poured. It is very common to pour columns 2 block lines below it´s level.

This tube goes inside the metalic columns that will hold the deck, this is a great way to hide pluvial drainage. It is quite a whole technique how to put the column after this, but it is a great aesthetic solution.

This is the typical way in which you check levels. Two people can hold a transparent hose one on each place where you want to check levels. Once one side is aligned at the desired height, let´s say here, 40 ctms. Then the other person on the other side will look for this measurement where the water stays leveled.

That is all for now. Til next week! Expectign again to climb that roof!

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JULY 2010:WOOD AND WALL-COLUMNS

SITE INSPECTION AT POAS VOLCANO CHALET, JULY 2010


This will be the main facade for the Mountain chalet..

This is our view right now…

This week we are only having electromechanical work and putting some block. All beams have the correct steel, number , location and sizes.

The owner is not completely sure about using teak at his deck. He has had previous negative experiences with it on the beach. This location is totally different, and there are 2 suggestions for treatment that we will discuss later on a different post, due to it’s importance.
Here we have some resins, but I don’t particularly like the product because it looks fake. All the nice work we are doing on the beams and other accents for wood, would not be benefited by this non-organic material.
We will see other products, like Dech Tec. It is supposed to be composed of wood and resins, and looks a little bit more natural.

Here we have our front wall- columns being poured manually with concrete.
When the concrete reaches a 80% of the desired resistance, 10 days more or less, propping can be removed. Right now we have secured both sides.

Till next time, maybe with a concrete slab ready to inspect!

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JUNE 2010: CONCRETE SLABS AND MOISTURE PROTECTION FOR RETAINING WALLS

SITE INSPECTION AT POAS VOLCANO CHALET

Poas Volcano chalet continued…
At this point of our work, we are almost ready with level 0.0 + 15ctms. This friday will be pouring the concrete floor.
In this picture , we are using a geotextile as a drainage membrane, next to all sides of walls that hold the slope behind the house.
It is also recommended to apply asphaltic paint , from the foundations up to the main level of the house. This will prevent humidity to go up into the house from the earth.

This is a great practice. Proycon Construction Company is keeping a guide line so all of our walls are completely straight, and we are not missing any mm’s when they install doors and windows.
At this moment I have checked measurements for kitchen, laundry and bathroom, and they are just perfect.
We are just missing one centimeter for the final layer of concrete, ” repello” or plaster.

The mechanical systems will be on the perimeter. From there they enter the house. This allows a simpler construction process.
Here you can see the connections.

This is our first level structure. Try to look deeply , and you will see and inclination on the edge. we did this because we’re trying to have the windows frames under the floor, so you won’t step on them. We brought down the structure one inch, but the concrete will be pored with no inclination. So the beam won’t intersect the frame.

You can see here the “helados” , small concrete levelers. You can also see the metal base for the deck attachment, into the floor structure.

The element held by the constructor, is what we call ” perro”. It’s a steel bar  that attaches to the metal structure that won’t let it move. With such people flow over the structure, the steel bars could deform. This piece won’t let that happen.

Men at work!

Don’t be surprised if men leave at 9:00 am all at a time. It’s their coffee break! This is typical in Costa Rica, and there is no way you’re going to suppress this important time for builders.
At this moment, they were just back…

Until next time!

MAY 2010:RETAINING WALLS AND CONCRETE FINISHES.

SITE INSPECTION AT POAS VOLCANO

As expected, men are working on the slope behind the house. After having it tested, the solution to retain the street upslope and the material itself, was to pour ballast cement tinted with local red sand over the existing terrain. Compressing it towards the wall, is the best way to keep it well formed. In this picture, its also shown the finish, a little bit more cement like. Over this we will put hummus and grass.
Please note the protection over the steel bars holding the line. This is a great security practice that costarican construction companies didn’t use before. It shows that we have had an important improvement in Human Security .

Retainning wall at house entrance. Due to location and angle of the house at this point, we cannot maintain a 1: 2 slope. This is a 1: 1 slope. The detail also asks steel bars to be closer to the block’s right edge. This section will be all filled with earth and ballaster cement.

Beam that supports concrete flooring and structure.

Wood cast ( formaleta) for floor beams. Great attachment to steel bars. First use wood.

Brace detail that goes attached to slab. This will direct stormwater to the ground like a well defined cascade. Water will be received by a cone like  stone surface in the grass.

This is a sample for ” Concreto Lavado” . Possible finish for some floor areas in the house. This sample was made with ” Piedra Cuarta”. I would be asking on ” Piedra Quinta” in case we pick this finish.

This sample is for ” Concreto Martelinado”. Same stone as above, works great as an antislip.

Sample for ” Concreto Lavado” . Definetly my favorite. It will look great with all the wood finishes. Contemporary flooring meets teak warmness…( teak beams and deck)

Teak 3″ x 8″ sample. Already treated with Sur Products. I will post on special wood treatments later.

Today we checked on chimney details, floor beams, stormwater conducts that go inside metal columns, window checks,  protection with asphalt paint on certain foundations and brick selection. I learned today that generally the common ” orange ” brick is less expensive than using recycled brick. It seems it’s a trend that many are following, and paying to the paupers that collect them adds a significant price over regular brick.
Till next week!

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MAY 2010: MORE ABOUT FOOTINGS, A DEEPER LOOK!

SITE INSPECTION AT MOUNTAIN CHALET AT POAS VOLCANO

In 6 months…you will see the contemporary chalet instead of those wood posts that keep our axes aligned at all times.

Today, our builders put a little propping to our foundations, to keep them straight, when they are putting concrete on other locations of the house. I really like this! This way we don’t miss our previous checks with the ” plomo” ( our word for the tool used to verify correct vertical alingment of the steel bars.

Please note our corrugated hoops, and the wire’s thickness. It is better than the standard.This is a good practice, that, according to our structural engineer at Ieca, may cost as little as 12% more on the estimated steel of the structure. When  budget allows it, and when having not very stable terrain conditions, this practice may be supported.

These are our pedestals, one at different levels at each axis of the house…They support metal columns up to the roof.

Mannual vibration of the concrete.

This is our seal or base of the foundations. We call it ” concreto pobre”. As you can see in the picture, the problem is to keep it clean. Rainny season has started, and we are having water coming into these ” pilas” ( excavations). It’s easy to remove with a mannual bomb, but builder needs to keep this area cleaner: no dirt on it.

Oversized foundation for a 2 meter street. Our ” maestro de obras” missed a number. Good that is was more than less…
This is 1,20 meters, and we asked for something of 85 ctms.

We are making decision on windows and wood. Very interesting suggested teak treatment by our builder. I will post about this later…
Till next week! Expecting to have that slope already finished ( not the grass on it though), and complete foundation concrete poured.
By the way, our concrete mix is already approved by laboratories…

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MAY 2010: MORE ABOUT SOILS AND FOOTINGS.

SITE INSPECTION AT POAS VOLCANO CHALET

We finally came up with a solution for the slope behind the house, after having experts from Insuma S.A analyze the behavior of this terrain containning a lot of hummus…( i know it’s too bad we’re building on an agricultural zone, but at least the owner has many undeveloped hectares near Poas National Park.)

This slope will have grass over the suggested ballast cement to be located over the 1:2 defined slope. The owner also suggested local plants like ” corona de cristo” that will help support or moor this soil.

Structural Engineer , Pablo and I also checked on the excavation made under the approved lines that mark all the axes of the house ( due to size and morphology of the house, there are many many axiss to check!)
Here, we have all hoops on #3 ( this house will never fall down…it’s a bit over structurally designed, very common in costarican enginners…) , we also have good bases, ” helados” called in costarican slang construction terms…
no protection on the walls of foundation is needed…

The house will kind of wrap around the tree in this picture. I told builders to keep axis references at all times, so we will keep on seeing those wood posts…
can’t wait to see them!

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1 comment
  1. MJ Johnson said:

    Me gusta! Quero comprar cuando regreso a Costa Rica. Tengo mi residencia ahora. Cuanto vale? Habla ingles? Prefiero ingles si
    posible. Mi espanol no es perfecta ya!
    Gracias,
    MJ

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