Stuccoing the skylight curbs

While we were waiting for the shotcrete crew, we continued on some side jobs.  One of which was insulating the skylight curbs and protecting them with stucco.  Detail on our mix recipe, etc. later, but first, the video.

The Video

The Mix

Here, we used the scratch stucco recipe of

  • 5 buckets (25 gallons) of sand
  • 94 lbs (1 bag) of portland cement
  • 17 lbs (1/3rd bag) of hydrated lime

 

We mixed this all dry and then used buckets of the mix, mixed with water (about 20 cups) using a drill mixer. After applying the stucco (it naturally forms a layer about 3/8ths of an inch thick), we used a “scratch” tool to give it texture so the second layer would grip it well.  Then we left it for a few weeks to cure and watered it often to increase the strength during the cure period.

The recipe for the brown coat was very similar, except with 10% more sand and lime to weaken it a little bit.  You want the brown coat weaker so that if it tries to shrink as it cures, it will crack instead of cracking the scratch coat off the wall.

Before applying the brown coat, it is a good idea to wet down the wall.  Otherwise the moisture from the fresh stucco is sucked into the scratch coat and it is difficult to work with.

After applying the brown coat, we continued to water it for another couple weeks, again to improve the cure and the strength.

Improved mix

As I mention in the video, along with our improving stucco skills, we also experimented with the mix and found that adding a quart of thinset after mixing in the water really improved the workability of the stucco.  It also improved the stickiness (important for ceilings) and gave it some waterproof characteristics also.

The Gallery

Again, sometimes the easiest way to tell a story is as captions on pictures.

Heavy Stone Retaining Wall

When you are burying a house, one of the tricky bits is to keep the dirt from spilling where you don’t want it…  Like into the doorways.  I have a number of retaining walls planned for this build, and, just to keep things interesting, I have designed each one a different way.  This section is about the “Heavy Stone” wall by the back door/patio.  More details below, but first…  the Video

The Video

Cost

I had assumed that those concrete blocks were the cheap way to build a retaining wall and the fancy quarried sandstone was the expensive way.  Of course, I probably still would have used some real stone…  However, when I looked into it, At least for the cost of the stone, the real stone was cheaper.  Of course, that doesn’t factor in things like the cost of the mortar, which was about 5$ per level on my wall, so still not too bad.  The real cost of building a wall like this is time…  Those precast concrete block walls probably wouldn’t have taken me nearly so much time, but no regrets on choosing to do this one the hard way.

Engineering

Retaining walls often fail.  Keys to keeping this one from going down included…

  1. Wide heavy stones (heavy stone is actually what they called this size at the quarry) that are substantial and want to stay where you put them.
  2. Leaning the wall back against the earth load.  Before the earth can tip your wall over, it would first need to straighten it out.  Gravity helps you keep things as they are.
  3. Curving the wall against the earth makes it a lot harder for the earth to tip it over, just as it is harder for a mug to tip over than for a domino.  Making the wall concave helps even further because the loads against it are in compression, something that the stone handles with ease.
  4. Behind the wall, I had plenty of drainage.  Drain gravel, landscaping fabric and HDPE corrugated/perforated drain tube were working to make sure that water pressure never gets a chance to build up behind the wall.
  5. Layers of carpet were also used in the dirt behind the wall.  This “geo-textile” idea is used by highway engineers to keep dirt from shifting under ramps.  I would have liked to have used more layers, but some is better than none.

 

I watched lots of videos online about how to build a retaining wall that lasts.  I recommend anyone who is planning to build there own do the same, and don’t be tempted to take shortcuts.

The Gallery

Here is a gallery of pics with detailed captions.

Making Copper Tiles for the Ridge Cap

I have always been a big fan of Copper roofs, especially when they patina.  Copper roofs last hundreds of years and just look so much more interesting than asphalt ones.  Problem is that they are just too expensive.  But with my earth sheltered home project, I was going to have very few square ft of roof, so copper suddenly became affordable again.  Making the tiles myself would also significantly reduce the cost. For this first part, I was really just wanting to put a copper cap on the front and back ridge of the garage. This post is about how I did that.  At some other point, I may also make diamond tiles to cover a few hundred feet of regular roof…  But first, this video

The Video

Alternatives

I had put stucco on the front and back of the garage and this ridge cap was to cover the 12-inch ridge along the top of the shotcrete wall…  Looking back, I could have done it a few other ways.  For instance, I could have just wrapped the top of the wall in lath and then just put stucco right up over the ridge.  Another option would have been to put tile up along the ridge.

I had planned to use copper shingles for all the skylight caps also, but now that I am older and wiser, I plan to just cap the second skylight on the garage with copper and switch to using large format tiles (that I can get for about 1$/sqft) on the other 5 skylight curbs.

The tools

The Press Break Roll was pretty fun to use and getting it 40% off from Harbor Freight made it even better.  One of these days I’ll put more details about it under the “tools” section of this website and maybe make a more focused video.  In the meantime, I can put the original crate back on top of it to keep the dust off so it is ready to use next time I am in the mood.

Along with that, I needed a nice mallet for pounding the copper, good aviation snips for cutting it, pliers, etc.  Generally speaking, pretty standard stuff.

The Gallery

Pictures help tell the story, so I put a bunch in the description of each image…  Enjoy.

Installing the Rear Garage Door

We had not left quite enough room for a standard garage install and had to get creative with our rear garage door. Here is the video…

The Video

Bells and Whistles

The door was from Lowes and came with the S3 winder so I wasn’t too worried about the torsion spring.  I got a side mount garage door opener, specifically a Liftmaster 8500, and was really happy with it.

One interesting side thing: The Liftmaster 8500 had a bunch of extra special features, such as a wireless light, programmable control, etc. but the most interesting thing (to me anyway) was the way the sensors worked.  Every other garage door I have owned had a sensor so that if you walked past as it was going down, it would stop and open up.  This is the sensor that you always “hop over” if you want to sneak out of the garage as the door is going down. How do you improve on such a basic sensor function? When I first installed it, it didn’t seem to be working, but then I realized that the improvement is simply to wait and see if the obstacle is there for more than a moment.  If you just walk past, it doesn’t trip it, no special hop-while-ducking required.  You need to interrupt the beam for at least half a second to stop the door from coming down.  Pretty minor, but it makes a nice difference 😉

Lath and Stucco

 

The style of the home is something my wife and I are calling “Modern Tuscan“.  To us, this means a stucco and stone exterior.  While the majority of the Quonset hut will be buried, the Fox Block ICF endwalls would be visible (and prominent) and need to be stuccoed. But first, we would need to attach lath to hold the stucco.  Since the work was pretty standard, I decided to hire a professional to take care of the actual stucco work.  This is the story of how that all came together, but first, the video.

The Video

Lath overlap

As always, this is a journal of my progress, not a “how to”.  I don’t always do things the right way at the start, although I do usually learn from my initial mistakes.  For the lath, I read about attachment details like how often to put screws in each direction (and then I exceeded it), but I didn’t pay too much attention to the part about overlapping the lath and just butt jointed everything so the surface would be flatter for the stucco. Probably I was also thinking about saving on lath.  At a later point, I changed my mind, so the later pieces are properly overlapped…  Either way, the professional stucco guys said we did a good job and only needed to add some J-pieces to form the bottom edge.

The window

With such a large and prominent wall, I knew I needed a window to break up the space.  Personally, I think a square window would have looked stupid, so I bit the bullet and budgeted for a nice round window.  At least I went with a standard diameter window so it wouldn’t need to be custom.

However, when I finally got to this stucco stage, I wasn’t ready to order the windows. I want to order them all at once to get the bulk discount, and I wanted to build all (or most) of the bucks before I order, so…  In the meantime, I decided to go with polycarbonate Lexan.  This is pretty basic stuff that you can buy from Home Depot less than 1/10th the price of a window.  The R-value is also pretty similar to a double pane window.  I figured it would at least give us a temporary solution that would keep the inside dry over the winter.

It ended up looking so good, I might just decide to keep it this way.  We will see how well it holds up to UV.  Obviously, if it yellows or cracks over time, I will switch to glass.  But it did claim to be “UV stable” and has looked fine so far, so I am optimistic.

 

 

Still, I wanted to make sure that the window opening was ready for proper glass so that the stucco edge would all be done correctly.  We used wood strips to form a curb, and then put two layers of the tar paper to protect the wood and then a strip of lath to hold the stucco.  Lots of screws…

 

Getting a Contractor

I have had many struggles with getting contractors to work on the more unusual parts of my build, but I was surprised to even have trouble getting something as basic as “stucco over ICF”.   Very few of these companies advertise properly, probably because most are kept busy by professional builders and are not actually looking for work. Eventually, I went to the stucco supplier and asked for a list of names and recommendations.  One of those paid off, but even then I had to wait quite a while to fit into the schedule.

Of course, the contractor, Hoffman Plastering, did a great job in terms of how nice and flat the wall was (they certainly had to compensate for my less than professional ICF job).  Their classic worm finish was also excellent.

Cracking

 

 

However, in the months after the stucco was applied, we did get a bunch of fairly obvious cracks in various places and we have not been able to get them to come out and take a look.  On the phone, they said that it was probably my fault. Essentially, they blamed the copper cap and said that water probably got behind the stucco and froze, but I was able to find pics showing the start of the cracks before the first freeze, also the cracks look more like ones that are caused by expansion and contraction of the stucco its self.  Basically, I imagine that if the south wall expanded in the sunshine, this narrow region would be the highest stress concentration and the most likely to crack. The inspector thought it may have been that the top layer was applied too soon after the brown coat. The contractor may have rushed that step because the work was done in October. The cracks are not wide enough to get the edge of a coin or screwdriver in there, but are still concerning. The conclusion of this story is still on hold, but I should probably do something before winter when water might actually get in thru those cracks and cause further problems when it freezes.

Future Stucco?

I wish I could hire a contractor to stucco the rest of it.  Their work was excellent (other than the cracking) and the quote to handle the rest of it was probably fair per square ft.  The problem is just the large number of square ft required. The majority of the cost is the professional labor, the actual materials are a very small fraction of the cost.  Therefore, I am guessing I will need to do it myself. With any luck, my skills will grow quickly.

Gallery

As per usual… A collection of pics related to the lath and stucco.