Kray Guest Post Part 3: Make Your Own Shake Siding from James Hardie Product – Estimating and Making Them

Now that I had my pattern and my area to shingle drawn out on graph paper, I could start estimating how many shingles I was going to need. One thing to note is that I have not accounted for spaces between the shingles. I recommend eyeing a quarter inch when you install. I had some that were closer and it doesn’t look as good. But there is really no need to go to the effort to add the spaces on graph paper. Using nominal 12, 8, 6 and 4 widths gets you close enough. So based on my drawing, I was going to need approximately 21 12-inch, 66 8-inch, 45 6-inch, and 43 4-inch widths. This estimate was a little high. I didn’t subtract out for the arches and I didn’t realize until installation that at the top I could cut each one in half. But I’d much rather have a few extra shingles than run short. Based on information in the installation instructions for Hardie shingles, I went with 15.25 inches in height for each shingle. Given the lap siding is 12 feet in length, this meant I was going to get 9 shingles per piece or 18 shingles per piece that I would rip in half.

I suggest you buy a couple of 2x4x12s to support the siding while you haul it through the store and in your truck. Plus, you can use a bag of concrete mix to weigh down the material on one end so it doesn’t fall out of the truck. This stuff will snap pretty easily being only 0.25 inches thick. You also need the wood to support the pieces later while ripping them. So for my project, I was going to need 6 pieces of 12-inch wide siding and 11 pieces of 8-inch wide siding. This amounted to approximately $150 for the siding. Since I knew I was overestimating, I didn’t cut everything up. I saved four pieces and, as it turned out, I just had enough for my project. I can take these back and get about $40. That means the end cost for the shingles themselves is about $110, a significant savings from the $1,000 minimum order. I did have to buy a $20 saw blade for my circular saw that is made especially for this stuff.

WARNING! WARNING! WARNING! Before you start cutting, it is best to read the installation instructions tips regarding cutting. This product contains respirable crystalline silica which is known to cause cancer and lung disease. After reading the instructions, you will see that I did not using the preferred method for cutting. The specialized saw blade I used does help keep dust to a minimum but I did not have any dust collection on my saw. So I wore a good respirator (one used for professional paint spraying with cartridges and not one of the cheap two dollar masks) and did all of my cutting out in the yard as far from the house as I could get. I also made sure nobody was around while I was cutting.

You can score and break this stuff, but this method will not leave you a nice finished edge that is easily paintable. It took me maybe 4 hours to cut all of my shingles. The cut edge was a little rough on the edge especially toward the end when the saw blade was getting dull. So I took an orbital sander and smoothed the edges (front and back) of each shingle. It doesn’t take much effort to knock the edge off. Again I wore my respirator due to dust concerns. I thought I would never get done sanding the edges…one shingle at a time. Once I had this done, it was time for paint. The shingles were all primed on one side to begin with, but I needed to prime the newly cut edges. To save time, I used a paint that had primer mixed in with it. I also used a small cheap foam roller. I rolled the edges first and then came back and rolled the front side. Then I let them dry out overnight.

(Caution: always follow the manufacturer’s instructions and best safety practices.)

Next time: installation