Polishing Concrete Floors and Starting Interior Walls

 

It may be winter but that hasn't stopped our progress this year. We had many things that we wanted to get done that didn't happen because of conditions but there is no shortage of work that could be done.

Our original plan had been to insulate the window and door walls with spray foam as the next project. This ended up not working out. We discovered (thankfully though research and not trying to do it) that the foam is sensitive to both temperature and moisture. These are two things that we cannot completely control right now in the middle of the winter. We have no problem heating the interior BUT since it is cold outside and warm inside we get condensation. This condensation collects on the uninsulated surfaces....also known as the areas we need to insulate. We briefly tried the idea of heat drying the surfaces before spraying but decided our time and energy was better spent on other projects. It was a bit like trying to swim against the tide.

We immediately went on to our next big project...polishing the floors. We scheduled our machine rentals for the end of January. We discovered that it would be cheaper to buy all the grinding bits and pads than to rent them. It is only cost effective to rent if you only need them for a day. This delayed us for almost 3 weeks waiting for all the supplies we ordered. What do we do with three weeks.... build the first interior wall of course! We didn't want to do too much interior stuff but one wall would be ok. Building interior walls means more hand edging where the big machine can't reach. It would clearly be much easier to not have a lot of walls to go around. This one wall does allow us to get rid of the temporary support structure (that is in the way) holding up all the radiant floor manifolds. 

Of course this wall isn't an easy one. It is one of several curved walls in the plans. After much research on YouTube watching how other people tackled the task, we set out to do our own version. 

Watch our curved wall YouTube videos  Part 1  and Part 2

We built this wall with plywood sheathing instead of sheet rock for several reasons.

1. It is super easy to bend two layers of 1/4" plywood around a curve. (We became well practiced building our curved foundation forms) To get sheetrock to do the same, you have to wet it and/or score it. We watched several YouTube videos of people using this method with various rates of mild success. All of them had issues.
2. The utility room is going to be the nerve center of the house and it is going to be jam packed with wires, conduit and tubing. Much of this gets attached to the walls. It is infinitely easier to attach these to plywood than sheetrock.
3. The side of these curved walls that face the great room are wood feature walls. They will be thin horizontal wood paneling. This is again much easier to attach to plywood. See the inspiration photo below for the paneling on these curved walls.

Curved horizontal slat wall inspiration for our curved great room walls

Building our curved wall took up the entire two weeks of time until our scheduled rental of the floor grinder. We joke that everything in this house is an art project. It is amazingly slow to build against the irregular curves of the shell. 

We are now 3 weeks in to polishing the concrete floor. We thought we could complete the floor in one week. This ended up being way too optimistic. After our one week was up, we had only barely finished with the first pass of the very rough 30 grit diamond bits. We realized too late in that first rental week that we had what was considered "very hard" concrete. We purchased bits for medium (or average) concrete. Because the rental place is not open on weekends, we had to waste two days using bits that were not effective in stripping down the surface. First thing Monday morning (we were renting Wed-Wed) we rented soft bond for hard concrete bits. They were very amusingly called "shark bite" bits.

This made all the difference! We were able to strip the rest of the floor in two days. Unfortunately this setback resulted in a second week of rental to finish the rest of the series of bits and polishing pads. We did 30, 60 and 120 grit diamond bits then 200 and 400 grit resin pads. 

First day of grinding with the 30 grit diamond bits. We found that adding a bucket of chain as extra weight on the head of the grinder was helpful. The clamps are there to give a gap between the grinder head and the bucket for airflow.

First day of grinding and blissfully unaware that we would spend 13 hours a day for two weeks straight using the machine. Most of the time going slower than a snail can crawl. Pro tip: Don't walk in straight lines as shown here. Instead swish it very slowly back and forth in a random pattern. We figured this out later and other areas came out much nicer.

The end result is a very smooth honed but not super shiny surface. We had originally planned to grind down to expose more aggregate but the very hard concrete means we would have needed a much larger machine to achieve it. The majority of the floor is a blueish grey dappled look with salt and pepper aggregate. There are some areas that do show 1/2" aggregate but they are only in the transition areas where the windows and tie beams are. 

This photo shows the finished floor in the process of being cleaned but not yet sealed.

Watch our first video about our experience polishing a concrete floor with the big grinder HERE.

For the edges we bought angle grinder polishing pads. 

We did not have a variable speed angle grinder so we bought a cheap variable speed buffer for $20. This works well enough and if we kill it we will just buy another. The pads attach with Velcro and if you attach them to an angle grinder that doesn't let you slow the speed they become frisbees!

We are currently still polishing the edges and cleaning up all the dust. The super fine dust is incredibly hard to pick up. So far we vacuumed with the specialized HEPA vac system we rented, dry mopped with two types of microfiber mops and tried regular wet mopping. We have finally come up with a better solution with the use of an old upright wet vac. We slop on as much water as we dare and use the microfiber mop to scrub then vacuum the whole mess up. This seems to be the only thing that works. 

Last but not least to include in our update is the progress with our windows and doors. Our inswing round top windows are having production problems. They were supposed to be delivered the week of February 8th. The company is working on fixing the issues with them and fingers crossed they will figure it out. In some ways a delay is actually helpful at this point. We can't install them until we get better weather to do the spray insulation first. The floor is also taking much longer than expected and we need it finished so we can store the windows inside. We got our quote back for the curved windows above the large door and it came back reasonable so we are going forward with them. This is super unexpected. We feared that large custom curved windows were beyond what we could do but this company has been great. Last but not least, our custom iron doors are scheduled to be delivered Monday March 8th! This is both exciting and great timing. We still need to finish polishing the edges of the floor, clean more and finally seal the floor. This will all definitely be done before they arrive! The doors absolutely have to be stored inside so we are relieved that they aren't coming before we will be done.