The Walls

 Once the slab was pored, and had rested over the weekend, we started laying the blocks.

It is very different from in Austria. There the complete walls are made of blocks. Here, however, the building code requires that corners, door- and window-jambs are pored concrete, and not just blocks. Looking at the worst practices block-layers are using here in terms of filling the holes, the small size of them (just 10 cm thick), and the quality range of blocks - from awesome to crumbling at the touch -  I guess, block-walls are not strong enough here to carry even just the light-weight roofs single family homes usually have here.

So we had placed the rebar for these concrete columns and the cariola frames of the doors on top of the rebar mesh before poring the slab, so they are firmly planted inside of the concrete.

[slab with rebar and doors sticking out]

Now, the spaces between the columns and doors are filled with blocks. 

I have three window heights - 180, 120, and 100 m (6', 4', 3'4") - but in the end they all should reach the same height in the finished wall. Thus, below the large windows only two layers of blocks were needed, below the regular windows four layers, and below the kitchen-window 5 layers of blocks are placed. The rest of the walls need eleven layers. Oh, in the bathrooms I have some small narrow windows along much of the wall, to ensure adequate ventilation and avoid too much moisture to build up. Underneath these windows there are eight layers.

[wall with two, four layers of blocks]

These special bathroom windows will not have glass in it, but only mosquito-netting. For the other windows we prepared cariola frames, similar to what we had done for the doors. 

[ bathroom wall]

Once the wall-pieces below the windows were completed, we installed the frame by welding them to the rebar the are at the center of the columns.

That sounds very easy and simple. In theory it is. In practice, however, that is a very tricky task! The rebar is not very stable but, as long as there's no concrete around it, it flexes easily. The window frame has to be exactly placed - it has to be vertical not slanting, and horizontal, not inclining in any direction, and exactly 1.5 cm overreaching the the blocks. The stucco that is later put onto the block-wall, to make it nice and smooth, is about 1.5 cm thick. If the window is not placed correctly, it will be very hard to get a nicely looking stucco applied later!

[window frames installed]

Well, this is not something the folks here do often. Heck, it is the first time, since I came up with the idea. So it took quite some trial and error to get it right. Some windows had to be cut out and rewelded multiple times until they were correct.

[window 2 rewelding]

With windows in place now, one team started installing the plywood forms for the corners, and columns on each side of the door- and window-frames. Once a few of them were in place, we created the appropriate concrete mix and pored it inside. With a 2 1/2 m long rebar stick the concrete was pushed down all the way after each bucket full was pored, to ensure a full column, without holes.

When we removed the form the next day, it showed whether that compacting was done sufficiently or not. 

[holes in the columns]

The door and window-frames were built using 3" cariolas - the are 7.5 cm wide. The wall however is going to be 13 cm thick. So on one side of the frame I needed to place something to make up for the missing 6.5 cm.

I decided to cut standard 2-by-6 into 3 stripes, and install these flush with the cariola. The advantage of this is, that later I can attach the actual door-frame - the nicely looking one made of teak- or laurel-wood - to this wooden stripe - which is much easier than to concrete, or even worse to metal with concrete behind it! Also, since the window frames were very hard to install exact location, there are variations in how thick that strip had to be. Again, much easier to accomplish in wood, than anything else.

[door column with wood in place]

In order to keep that wood securely attached to the concrete column I thought I'll drill screws into it, letting them stick out in the back, so they will be embedded in the concrete. No need to drill holes for ankers!

Another interesting building code specialty here is this: the blocks are not laid all the way to the top of the wall, but 20 to 40 cm lower. On top of the blocks they cast another form for a "viga" (spanish for beam). Again, this is to strengthen the structure, tie all the block-wall pieces and columns together, and create a strong uniform base to put the ceiling or rest the roof trusses on.

It took almost three weeks to get the walls done. 

Lessons I learned:

First, since the rebars and door-frames were not placed exactly and firmly there was a lot of difficult finnagelling necessary to get the walls completed. Yes, when the foundation is not right, the longer you wait, the harder it gets to correct issues!

Secondly, It's difficult to install the window-frames exactly as they are needed. However, the more effort is made placing them, the easier it is later to create the casts for the columns and poor concrete. And, the easier it is later to apply the plaster.

Thirdly, when cutting pieces of rebar to measure it is not sufficient to place the in the general area where they will be needed. Because anybody may just decide to grab anything they see anywhere and cut a piece off of it! Then, when the original piece is needed it's nowhere to be found anymore, and has to be cut again! While the crew is waiting dwiggling their thumbs! Next time, I'll put some kind of marker on it. Maybe a piece of yellow "caution" tape, or such. And tell the folks, if they  touch one of these items with such a marker, they'll lose their job!!!

What went well, though, is: because everybody is so used to improvise all the time about anything, the workers were able to compensate for all the little difficulties and inaccuracies encountered! And, all in all, the walls went up relatively quickly, and appear to be sound and generally nice!