Today we worked on the Library Desk giving it a front curve and a moat for the aquarium that will go in front of the window. The pour of the structural arch from last week is now mostly cured and very solid. Since there is no reason to remove the supporting scaffold under the arch yet it will remain there for now. Giving it a full 28 days to cure is ideal. In the photo above Holly’s examining the arch of the desk. It is thick at the ends where it joins the partition walls and rises up in the middle to give space for knees, a file cabinet, etc. This shape will help support the 500 lb freshwater aquarium that will be in the middle of the desk.
The next step is to curve the front edge of the desk so that it forms two separate working spaces each facing away from each other by about 90 degrees. That gives a little bit of privacy in a very small space. Each wall will also have book shelves and bulletin board space.
The first step was we built an extension to the form and added a curve perpendicular to the arch. This will create a flat under surface, all the better not to bang knees. The curve produces the change in sitting angle for two different chairs that face to the corners of the desk while also having the view out the east window.
This extension of the desk does not need to be as strong since it won’t support the tank and it is supported by the structural arch of the desk. Thus it can be thinner leaving more knee room. Still, it will be 2.5″ thick and once fully cured that PVA fiber reinforced concrete will be remarkably strong.
This form consisted of the 2×6 that had been the front form of the desk before, thus saving cutting a board. A 2″ piece of foam is the bottom and then I cut a 1″ thick piece of foam for the curve. The height of that 1″ foam is set to be the top of the concrete counter such that screeding the poured in place desk will be easier. The tank moat inset will also be at this height as shown in later pictures.
In the photo above I am wetting the just past green concrete of the structural desk with a slurry of neat cement and water. This will help the new concrete bond to the older concrete. To further aid the bonding I roughened up the desk surface while it was still soft and then scored it after it was firmed up.
While I wetted down the desk for it’s next pour Will worked on wetting the bedroom floor for it’s level sub floor coating. The bedroom is upstairs, that is to say up two steps from the commons room. This will help warm the bedroom in the winter but more importantly it gives a lot of storage space under the bed. Since the bed takes up most of the room we don’t need a high ceiling so raising the floor makes sense.
Another little trick is that this puts my desk, with me sitting on the side of the bed, higher up so my marine aquarium is higher giving more shelf space in the bathroom which is on the other side of the aquarium. By putting things at slightly different levels I get a little bit more use of the available small spaces in the tiny cottage. Holly and Will joke that I’m folding space and should write a book called “Concrete Origami” – Some day…
Our mix master Ben kept me supplied with the varying types of concrete and colors I used today. He just turned ten and already has a trade in construction he can fall back on if the rocket science scholarship falls through.
Because the weather has turned snowy and cold again we moved the mixing back indoors which Ben greatly appreciated. The cement is still outside and he puts it into the red buckets with water outside to minimize dusting inside the tiny cottage. Above he is slowly adding sand to his mix.
With many of our projects we’ve practiced floating them smooth even if we then score the surfaces up. The reason we’ve spent so much time doing that is to get good at floating and it has paid off. I got a virtually perfectly level and smooth surface on the desk. I had set the foam form curve along the front to be used as a screed edge and the foam insert in the middle where the tank moat is going also helped. Both of these are at the level height I wanted for the final concrete.
The top surface of the concrete for the desk is brick red. Years ago I played with concrete pigments a little but it has been a long time. I found I had to use a lot more pigment than I expected to get the color I wanted. That is why we did the bedroom floor at the same time we did the desk. Batches that weren’t quite right went on the sub-floor where they didn’t matter. Once Ben got the mix perfect we switched to the desk and then finished the floor off once the three buckets for the desk were done. The resulting color looks very much like terracotta.
I did find a couple of small flaws I wasn’t able to float out so I spackled them and floated a bit more.
I’m very pleased with the resulting desk. After we got done I realized that it looks like a sigma-∑ and is on the east wall – Cool! The pink foam in the middle is a 1″ depression in the desk that is about 3″ larger than a 50-gallon aquarium base. This way if the aquarium leaks the water will go down the drain hole at the south end and out through a floor drain thus protecting the contents of the desk and floor. If an aquarium were not there it would be a perfect place for house plants. As a fall back, the spot could have a piece of wood inset. All sorts of options.
On top of the tank moat foam inset are weights, pieces of concrete block, to keep it down in the concrete. Otherwise the foam might float up a little and get air bubbles. On top of the blocks are several molds containing concrete to make tiles, bricks and a concrete butter dish that Holly requested.
Under the desk is the elephant toy, the big concrete vibrator. I hung it from strings off of the desk extension scaffolding. The vibrator helps remove air bubbles from the concrete making it denser.
Plain red is boring. So I splattered color onto the surface of the floated desk and then floated some more.
This produces smears and clouds of color. I used a wad of paper towel dipped in iron oxide pigment to add more splotches of color and floated some more.
Later, after the desk has cured some, we’ll grind and polish it. I’m not looking for a high gloss sheen but I do want a smooth rock like surface. My hope is that the colors will then look something like marble. We’ll see how it comes out now that it’s set in concrete!
Hope got a very big kick out of making her hand print in the concrete and signing her name along with everyone else. This is in the floor over under the bed in the storage area. Hope got such a big kick out of it that she begged me to let her do more hand prints. So we let her make a whole lot of hand prints over near the doorway while Will floated the floor of the bedroom. Concrete’s highly alkaline and a bit hard on the skin so we washed her hands well and often. It was worth the fun.
A view out the front. Note that these window views were Photoshopped because the outdoor light is so bright the camera just can’t handle it. See this post for more cottage views if you haven’t already.
We made a number of molds out of foam and packed them with the colored concrete. These will be tiles that we can practice polishing and grinding as well as some other things like the afore mentioned butter dish. Doing the tiles has given me ideas about making bricks. I have literally tons of 200 year old bricks in the old farm house and I have a pile of new bricks from another project. But it would be interesting to have specially shaped bricks for doing arches. I’ve figured out a simple way of making them, not like Ben and I are doing here. I may end up making my own bricks that are shaped for each of the arches and pre-aged.
After a long day of concrete work everyone deserved a big treat so I sprang for pizza and made a chocolate cake. Not! That cake, delicious as it looks, is a bit on the heavy side and you would break your teeth on the first bite. I’ll leave it to your imagination as to the ingredients… We did go down to the Waites River General Store to get a pizza and movie for dinner – my treat!
Outdoors: 28°F/17°F 1″ Snow, Overcast
Farm House: 58°F/46°F no fire
Tiny Cottage: 53°F/46°F
Walter Jeffries Tinker, Tailor… A bit eclectic & a tad eccentric, polymath, quantum mechanic & Farmer. Also lucky at cards.
I am in awe of you and your family! This project that you all are doing is awesome and I enjoy seeing the process. I wish I could be half as self-sustainable as you all are! ;)
seeing you work with cement reminds me of sending time with my grandfather. he was a profound genius. i have a newspaper article somewhere that highlights his lifetime achievements. his cement creations were amazing–organic to the point you’d swear they were created by nature. i looked for the article the other day without result. when i find it i’ll put it up on the web. you’ll appreciate the fountains, brooks, ponds, flora and fauna all made from concrete. my parents still have a deer fawn that he and i made when i was six or seven.
Hey Walter! We pour a lot of concrete and color some of it and I was astounded at how expensive those store bought pigments for that are. I started using colorants from a clay (potters) supply, since I had them around anyway and they are MUCH more affordable. It’s probably the same stuff anyway. You can get 50 lb. bags of red or black iron oxide for about $35. If you are going to use it a lot it might be a better deal. You may have some good deal already but most people don’t think about that source. They have many other colors too. We also use a beeswax finish on the concrete countertops and it looks and wears real nice.
Rex, for the small colored batches we’ve done so far I’ve just used the pigment that comes in 8 oz tubes. I have found several sources for 50 lb bags to use when we do floors. If you have any web links for sources of pigments I would be most interested in knowing them. Thanks! -Walter