Post-Workshop

Some recent pictures:

Moisture Levels

I wish you all a HAPPY New Year!

Here are the latest humidity measurements from august to december 2010 - unfortunately the batteries in the logger lost power the day we left... so I have no measurements from 19.12. to 9.1.2011.

I reduced the number of loggers in the graph to make it more readable. The orange line is the logger in the middle of the straw bales in the dome, the purple one is a logger in the foam glass (about 20cm in from the outside, in a valley). The grey and black lines are outside and inside temperature and relative humidity measurements.

Open publication - Free publishing - More straw

What I think is interesting:

- The humidity levels increased during autumn in the straw bales, although the dome was covered against rain and wind could dry the plaster.

- Ventilation with heat recovery did lower the humidity inside, but because we put on heating at the same time, the humidity levels increased slightly in the beginning.

- After getting the moisture level below 65% inside, the humidity in the bales started dropping as well. This has continued until today, the last measurements shows 68% Relative Humidity in the middle of the straw.

- The moisture levels in the Foam glass is also dropping, very slowly and the drop started later. Also other sensors show a similar behavior. All sensor in the outer areas (cold areas) show relative humidity levels above 90%.

For the moment I think the straw bales are OK, what is happening in the last 5cm below the EPDM we don't know. Guess the clay absorbs any excessive moisture.

As for the inside temperature: we have had the heating on continuously in december and january, and the temperature inside stays around 20°C as long as the outside temperature does not drop below zero. We have no good door yet (just 6mm plywood) and one window is broken. And we are removing a lot of moisture, and that is rather energy demanding.

I guess with the door in and when we get some computers and people in, we will be fine even at -10°C. The inside temperature dropped to a minimum 17,6°C, never lower.

Open publication - Free publishing - More straw

Winter!

Today we have -7°C and the temperatures are still dropping. Inside we are able to keep a comfortable 17°C even without a proper door... just with 1900W from heating cables.

The snow makes everything look prettier - even the mud slide is covered up:

From Strawbale Dome Minke

There is no sign of any snow melting, so the insulation should be fairly well done. Only the oak facade is visible. The temperature of the earth under the foam glass is 14,5°C (middle of the dome) and 12,2°C (under the windows) and has been stable for the last few weeks. Another good sign is the gradual decreasing of the moisture level in the straw bales. The main measurement in the middle of the bales has dropped from RH 89% to 78% and is dropping further. Thanks to ventilation and a dehumidifier we now have 36% humidity inside the dome. So we believe the dome is safe for this winter.

From Strawbale Dome Minke

With snow come winter sports. Here is Kristián preparing for snow boarding.

From Strawbale Dome Minke

The only close hilltop is of course the "Dome":

From Strawbale Dome Minke

Good style!

From Strawbale Dome Minke

Next time we have to build bigger... :-)

Landslide!

When I said autumn was arriving fast, I mainly thought about the sinking temperatures. But there has also been more rain lately (if that is possible this year!) and as a result of some downpours we have some bad news to tell. Real landslides took down the green roof earth bags in seconds... see for yourself:

From Strawbale Dome Minke

All this happened on Nov. 19th

From Strawbale Dome Minke

The speed of the landslide is easy to imagine, the earth bags spilled out several meters at the bottom - it happened at night, so we did not see it.

From Strawbale Dome Minke

We thought that would be it, but two days later another two sides came down:

From Strawbale Dome Minke

Zuzana did her best to move the bags back, but they are really slippery and heavy when wet!

From Strawbale Dome Minke

And muddy!

From Strawbale Dome Minke

The good news is that the dome is still holding up, no new cracks appeared, even if the dome is now under uneven loads. 4 sides are still holding up. We now plan to put up some wooden sticks around the dome, tie them together with some strong rope, and then put the bags back up. That should stop them sliding down. The problem is that we have had no time and tomorrow the first snow and frost will arrive.

Maybe rather handle frozen bags than slippery mud...

Autum is approaching fast - you can see it on the colors. Today was the first day with temperatures below zero at night.

From Strawbale Dome Minke

Inside we have finished most of the window sills. First the wood fibre boards got "painted" with clay slick:

From Strawbale Dome Minke

then plastered:

From Strawbale Dome Minke

From Strawbale Dome Minke

with a great result:

From Strawbale Dome Minke

We removed the "coffee" plaster, just to make it again - but this time without the bleeding of the coffee beans.... hopefully.

From Strawbale Dome Minke

Outside work is progressing as well. The metal covers are also nearly finished - but one day work for each vault...!

From Strawbale Dome Minke

And with a bit of bad luck we also broke a window - luckily on the only window that was not finished inside!

From Strawbale Dome Minke

The last window sills on the outside got mounted. The technique we used to glue them to the glass works fine, really strong bonding if you use special primers for glass and metal and use 3M acrylic tape. For straight sills the 1mm tape would be perfect, but because of the bent border a 2mm thick tape would have been a better choice.

From Strawbale Dome Minke

Some plants were moved from the field to the area around the entrance. A preliminary door opening has been made.

From Strawbale Dome Minke

As you can see the bags are slowly covering the whole dome. Exciting last few meters of the dome to be covered...

From Strawbale Dome Minke

Not enough bags!!! More filling to be done:

From Strawbale Dome Minke

and planting:

From Strawbale Dome Minke

The dome is holding up well - no cracks on the inside to be seen.

From Strawbale Dome Minke

Nice view of the entrance in the evening sun. Never thought the yellow and red bags would look that good, great autumn colors!

From Strawbale Dome Minke

A big THANK YOU to all the volunteers that have been helping us out the last few weeks!

More to come - the ventilation unit has arrived, and will be mounted the next few days...

Weekend Green Roof Workshop

Today we got up a bit late - the workshop started at 10 o`clock. But we still got a lot done. First we had to get the EPDM in the right position, and glued to the skylight at the top. The EPDM stretches easily, which is a great help but also makes work sometimes difficult. We had to pull the EPDM back up because it stretched too much at the skylight:

From Strawbale Dome Minke

We put some geo-textile across the dome, but difficult to walk on it because it became very slippery. We should have fixed the skylight plexiglas before covering with any geo-textile, would have been easier. The geo-textile was then weighted down with bags of earth.

From Strawbale Dome Minke

In the lower parts we choose to work without geo-textile, because it would slide down and anyway, the earth has no sharp stones. We managed to get one valley finished, the bags are heavy but work well.

From Strawbale Dome Minke

We are fixing the EPD with some pieces of oak on the outer walls, with a enough material for the valleys. Then we cut the EPDM along the outside of the oak. The top part of the wall will later be covered by titan-zinc alloy sheets.

From Strawbale Dome Minke

Tom Rijven is inspecting the windows. They are now taped from the inside and insulated, so we can start making the last clay layers around the windows tomorrow.

From Strawbale Dome Minke

We will not finish the green roof tomorrow, so more workshops will be necessary... :-)

Last few weeks...

And we are back! The last few weeks we have been waiting for the Dome to dry. The plaster dried fairly quickly, also the floor inside. But the moisture levels in the straw bales has been difficult to understand. Even after weeks of drying the plaster the moisture level in the middle of the straw bales increased from 85%RH to 90%RH. The sensors in the straw bales just below the outside clay plaster has been increasing with higher outside temperatures and lower with at low temperatures - the opposite of what I would expect. The average moisture level in these areas are about 95%RH... of course the weather has not been very kind, here one of the rainy and windy days, but the clay still seems to be fairly dry.

From Strawbale Dome Minke

After the floor dried (took about 10 days) we put the windows in. Then I taped them from the outside. And we started to heat the inside:

From Strawbale Dome Minke

Domas from Lithuania stopped by with his friends on the way to Italy - we had a great evening!

From Strawbale Dome Minke

The border between the floor and the walls that had been covered with cardboard had to be fixed. The gap has been filled in by Catalina today. She arrived from Hungary yesterday. Now this part is also air tight:

From Strawbale Dome Minke

From Strawbale Dome Minke

From Strawbale Dome Minke

And the big news: we decided to take the roof down and put the EPDM on. Here is the roof cover being taken off:

From Strawbale Dome Minke

From Strawbale Dome Minke

On some spots some dew in the morning had been dripping down from the tent, so a hairdryer was used to dry the clay surface:

From Strawbale Dome Minke

The EPDM from Athos Syntec arrived in one roll and needed to be refolded on the nearby field:

From Strawbale Dome Minke

From Strawbale Dome Minke

Then we started to take apart the wooden construction - this was not too difficult:

From Strawbale Dome Minke

Even the last element was standing nearly on its own - really a good design:

From Strawbale Dome Minke

From Strawbale Dome Minke

First picture without the roof!

From Strawbale Dome Minke

We were putting geotextile around the wooden parts to protect against any sharp elements:

From Strawbale Dome Minke

The concept I had to put the EPDM on worked much better than we thought - after lifting the EPDM up it took just a short half hour to cover the whole structure!

From Strawbale Dome Minke

The hole in the middle is 90cm diameter - just a bit smaller than the frame to have a good fit:

From Strawbale Dome Minke

The membrane was then lowered onto the structure, and gravity did the rest of the job:

From Strawbale Dome Minke

From Strawbale Dome Minke

The membrane is definitely big enough, big chunks will have to be cut out:

From Strawbale Dome Minke

The membrane covers everything - tomorrow we will adjust the EPDM, fix it and cut off the parts in front of the windows:

From Strawbale Dome Minke

In the evening Tom Rijven arrived from Poland! Another nice evening:

From Strawbale Dome Minke

Tomorrow we hope to get a better fit for the membrane and then we will start with the green roof! Will be back with an update!