Major milestone reached

The time we have been slaving to finish the bunker really seems like a small eternity.  Since last September, more than 30 tons of junk has been manually wheeled out, and close to 10 tons of gravel has been carried in. Considering all the renovation projects we have ever been involved in, the bunker clearly ranks as the most demanding one.

So finally, after ten months the big day had finally arrived. It was almost touching to see the concrete pump truck slowly turning to the backyard alley.

Truck-mounted concrete pump arrives

Of course, we had the option of casting the 17 square meters concrete slab ourselves. But having to acquire the know how, rent the equipment, carry hundreds of sacks of cement and investing all the time that would have been required, it was simply not a viable option. Additionally, the offer we received from the concrete company was very reasonable, which of course made the decision making even easier.

Pulling out the hoses

The preferred option was indeed to enter from the backyard. To achieve the bunker, close to 50 meters of hose was needed. However, the alleyway leading to the backyard had been softened by heavy rain this summer. So would the heavy trucks be able to climb up the slippery grass slope was the biggest question mark of the entire project.

The Plan B was to enter from the front of the apartment and approach through the upper floor, via the staircase all the way downstairs. However the idea of pulling a filthy hose through our home was not the most appealing one.

50 meters of hose

Once the set up was ready, the concrete truck arrived.

Concrete approaching

This time, it was not so easy. Whereas the lighter pump truck managed to climb up the slope, the soft and slippery grass was a huge challenge for the much heavier concrete truck. More than ten times the driver tried to desperately climb up the slope, but every time the tires started to slip on the grass.

The situation was critical. There is a certain time limit when the concrete has to be poured in as it naturally will start solidifying very soon. Of course we could choose Plan B and enter from the front, but it would have meant disassembling and reassembling all the hoses, and also protecting the upper floor from splashes. Clearly, quick decisions were needed.

Our neighbours must love us!

Finally after fifteen minutes, taking a slight side track helped and the heavy truck managed to slowly climb up the hill. Needles to say the sense of relief was enormous. Just like in life in general, also in renovation a bit of luck is a necessity!

Approaching

Perfect match

Of course, Urho's tasks was once again to manage the project - but from the the upper floor. A small dog, big machines and a strict time limit is far from a good combination, so his remote positioning was chosen only for Urho's own good.

The general manager

The feeling of finally seeing the concrete covering the prepared floor was unbeliveable. The guy responsible of pouring had a remote control unit attached to his belt and by pressing a button he was able to control the concrete pump.

Vesa pouring the concrete

Touch down!

Again, a laser was used to level everything with the mark defined by Pekka earlier.

Leveling with a laser

Whereas the first guy was responsible for pouring the concrete and roughly levelling it, the second one was working his way out from the bunker and ensuring the predetermined level was reach everywhere.

Manual levelling

It was great to watch the professionals at work. To gain a perfect end result this job clearly requires true craftsmanship combined with solid experience.

Cratfmanship in action

The last thing to do was to cover the concrete to prevent it from drying too fast. This can be done either by using a plastic sheet or spraying a protective layer on top. We chose the latter, as the spraying was easy to do after manual levelling.

Now, all we can do is to sit and wait. For us, this is a major milestone. Both physically and psychologically. Almost a reason enough to open a bottle of wine and celebrate (which, actually, has also already been done...)!

Future floor

Preparing for concrete

Preparing foundation for a concrete floor seems simple and straightforward. And in a way, it is. But if you do it yourself, for a first time, over evenings and weekends after work, some thinking and perseverance is required to get it right.

So here is what we did in the bunker. First, the bed of gravel had to be compacted as much as possible. The easiest way was to rent a plate compactor.

Plate compactor

To determine all gravel was equally levelled, we used a laser. So handy that it makes you wonder - how was something like this done before the time of these miraculous pieces of equipment?

Levelling with a laser

You also need to leave a small space between the wall and concrete floor. To accomplish this, some hot-setting adhesive and foamed plastic were used.

Rolling out space to be

Next, the insulation layer made of 50 mm thick expanded polystyrene sheets was fitted in place.

Last look at the gravel!

Of course given the irregular shape of the space, there was a lot of detailing to do. Once again, hot-setting adhesive was very useful.

Glue Master at work

Sofi also seized the sudden opportunity. It is not very often when colouring the floor is allowed. And it probably shouldn't have been allowed now either, given the guidance regarding consistency in raising kids. But it was just so much fun!

Guess what is my favourite colour?

On top of the insulation Pekka unrolled a layer of separation fabric, which was finally followed by a reinforcing steel wire lifted up a few centimetres with plastic holders. This was to ensure the positioning of the reinforcing wire in the middle of the concrete slab.

Wired

Holding up

The last thing to do was to protect the walls from any potential splashes of concrete. Now, fingers crossed all goes well with the concrete delivery and we soon have a floor underground!

Ready for some concrete action

Walls & Ceiling

We are only recovering from the installation of the slate floor when new construction materials started already appearing on site. Suddenly the focus went from floor to the ceiling and walls. The slate floor still needs a lot of attention in terms of washing, seaming and protecting, but as you are to find out soon, it makes more sense to do the finishing work a bit later in the process.

Nearly finished slate floor and more construction materials

These are exiting times. Almost two years, with the help of our dear friends we have focused our efforts on demolishing structures rather than building things. Now the break point has been reached, the building has begun. To make our lives a bit easier, the work is conducted by a construction company. We are very happy, as the guy primarily responsible for the project is fast and the quality of his work is excellent. Interestingly, Sofi has also learned to call him by his first name...

Wooden studding

The part of the ceiling that required insulation (below the atrium terrace floor) was studded with a wooden structure, which was attached directly through the insulation to the concrete itself. The area below the kitchen floor did not need insulation and thus had much more vertical space available, and was studded with an adjustable aluminum structure. Even though there is quite a big difference between the two areas in the height of the space between the concrete and the suspended ceiling to be, for visual reasons we wanted the ceiling to be all levelled.

Wood & aluminium studding

It is amazing to see how fast these guys work. Practically in no time the surfaces made of gypsum board just started to appear! Some of you may remember the visualization made by Pekka in Vision update, and that we wanted to leave some of the structural elements visible, just the way they are typically done in the MCM post and beam architecture. One of these elements is the main steel beam supporting the atrium terrace, together with the vertical steel posts supporting the whole structure. These structural elements will be painted black whereas the rest of the ceiling will be white. 

Also the wall which will host a teak slat wall is starting to take shape. Next, black acoustic panels will be attached on top of the gypsum board, eventually followed by the teak slats. A glimpse of a vague light in the end of the tunnel, perhaps?!

Visible steal beam & slat wall to be

A few days ago, we had a great idea of cleaning and seaming the slate. Now looking back it would have been hours wasted. Once again the downstairs including the circular staircase has transferred to a war zone with tools, materials, dust, sweat and dirt all combined to a lovely mix.

War zone 

And Urho? Not too much seen in downstairs these days. A bit too much action to his taste. In summer when it's warm, he makes sure to take the advantage of the sun and the couch at the atrium terrace. If the weather allows and the terrace door is open, Urho temporarily turns to a hot dog. What a life!

A hot dog

Slate floor, Day 3

Day three of the slate installation was all about details. Challenging areas with for example difficult access (e.g. the area underneath the circular staircase) were left to be finished last. To be precise, however, Harri did install some of the pieces around the staircase already during the first day. This was important from the tactical perspective, as leaving them to dry for few days enabled him to lean on them while installing the rest. Sounds like the voice of experience, doesn't it? 

Harri at work

Of course, not all of the pieces of slate fit next to each other perfectly right away. In these occasions where the match is not natural, a bit of persuasion with a grinder and a slate hammer is required.

Some evidence of past persuasion

Basically, you start by drawing the outline of the required cut. Next you use a grinder to create a general cut line. Importantly, the cut line does not go all the way through the stone but rather facilitates breaking of a slate correctly. Last you break the piece with a hammer, which gives the stone a more natural break line visually complementing the non-modified slates.

Man vs. slate

It took Harri and his assistant Pekka 22 hours to install all 30 square meters of slate floor. Next, a careful wash is needed as the floor looks and is filthy. Afterwards, Pekka can start seaming the floor, and finally apply a protective coat on top.

We would like to thank Liuskemestarit not only for the slate but also for the installation service they provided. If you are interested in a slate floor for in or outside areas, we'd be glad to give them our warm recommendation!

The very last missing piece

In the last post we showed you some of the testing Pekka conducted in order to find the exactly right tone for the seam. We have already chosen the slate we prefer but now there is the tone of the seam to be decided also. But this is not the end of it..

Spectrum of titanium oxide concentrations

You can also apply a toner on top of your chosen slate. The toner is not necessarily required, but it will work as a protective layer and helps to keep the slate clean. There are several different finishes to choose from. So of course, here as well Pekka did some testing with products kindly provided by Liuskemestarit.

Top left corner: No protection
Top right corner: Lantania, Avo
Bottom: Lantania, Twinsebin.M

Of the above choices, we liked the Lantania Avo -protector the most. It turns the tone slightly darker vs. the original, but does not result in a "wet-look", which was not an option for us from the very beginning. Also, Avo seems to have a bonus effect when compared to the look created by the Twinsebin.M. It hides away tiny little grains of dirt from the stone surface (something which seems to be characteristic to this type of slate) resulting in visually more homogenous look.

Natural vs. Lantania Avo

Finally, the flip side of the coin. Peak on the backyard shows that it is simply a disaster. Luckily, we are still in good terms with our very understanding and supportive neighbours.

The dark side of renovation

Slate floor, Day 2

The goal was clear. The tasks were divided as before. The determination was obvious. Come Monday, and we were back in the slate floor business. And as expected, the process was encouraging.

Harri cutting a stone with a diamond blade

Most of the floor has now been covered with slate. Even though the pieces are filthy, covered with dust and dirt, by a bit of eye-squinting and imagination one can already start to understand how the floor will look in the end.

Harri installing slate

Given it is a rather small area, the amount of cement used for installation is overwhelming.

Floor, slate and a whole lot of cement underneath

While the professional in charge, Harri has been installing the stones, Pekka has been reponsible for mixing cement. The current sack count just reached 59 sacks - in other words, 1475 kg of it. And somehow it seems we have not seen the end of it yet...

A whole lot of empty sacks

In parallel to this installation madness, there is an interesting spin-off project ongoing including 1 kg of white powder, a digital scale and some mixing instruments. Yes, we chose to go with a lighter color seam but before we can start to seam the floor there are two very important questions which need to be answered: 

1. Just how light do we want the seam to be exactly? 
2. Once we know the preferred tone, how do we achieve it? 

The laboratory

Easy. Basically, you take an ordinary filler and mix it with a pigment. For lighter tones titanium oxide (the white powder) is used. Would you prefer a darker tone, iron oxide would be the reagent of choice. 

And this may not come as a surprise, but as once again, Pekka did not want to take any risk in not getting the tone correct, he approached the challenge quite scientifically. He prepared a series of test mixes, each of them with a very specific amount of titanium oxide within the mix. 

Color samples drying in the sun

The finished color samples seem to work quite well. In the different mixes, the concentration of titanium oxide ranges between 0% - 6%. All there is to do now is to choose the one we like the most. The ultimate seam.

Which tone would you choose?

Overall, also day two was very successful. There are still some pieces missing here and there, a whole lot of unfinished details and all of the seaming to be done, but things are moving forward. We'll be back, very soon!

Day two checkpoint

 

Slate floor, Day 1

Almost a year after the slate floor stones appeared on our backyard the time has finally come to install them downstairs. Unbelievable, finally an obscure pile will be transformed to a beautiful floor!

The process began by Pekka once again carrying things. He laid out some of the available pieces (instead of keeping them in a pile on the backyard), thus making the selection process much smoother. This way it is easier to choose the pieces which best fit next to each other.

Choose your piece!

If you have no previous experience in installing a slate floor, it might be a good idea to call a pro to do the job for you. It is does not seem to be the most difficult thing in the world, but there is one fundamental challenge: if you screw up the only way to backtrack is with a hammer drill. So no, it is not Pekka in the picture below!

Professional at work

There are basically two ways you can make sure that the stones are all levelled. You can either use a good old bubble level. The more modern approach is to rely on a laser.

Restricted by the red line

In this process, Pekka had three responsibilities. The first was to make sure there is always a good selection of stones available for the installation, in other words carrying the slate inside from the backyard. The second was to mix cement and naturally - carry it inside. During the first day, 30 sacks of cement each weighing 25 kg were consumed. So you are starting to get the picture of Pekka's preference on how to spend his vacation days!

The last job will be to seam the slate. We have had some debates weather we should go with a lighter or darker tone (vs. stone colour) for the seam. At the moment it seems we are settling for the "lighter-than-the-slate-itself" option.

Still a bit rough around the edges

During the first day, the guys managed to install almost half of the stones, which accounts for approximately 15 square meters. Not bad, not bad at all - to be continued on Monday.

Day One checkpoint