Tiny House Episode 7: Installing the Roof

As I mentioned in a couple of my previous posts and videos, the roof couldn't be completed on the tiny house until the siding and trim was done because we have no overhangs. With the siding and trim complete, the time had come to finish the roof but what to cover it with?

We considered several different roofing options but ended up choosing asphalt shingles. This might seem like a weird choice for a tiny house, as most of the tiny houses we looked at online had cedar shingles/shakes or metal roofs. We decided to analyze how these three roofing materials compared with each other and can let you in on why we finally settled on asphalt shingles.

Roofing Material Comparison

Cedar shingles are probably my favorite choice in terms of aesthetic value. I just really enjoy the natural look of cedar. Unfortunately, this material comes with a high price tag. Cedar is almost three times as expensive as asphalt shingles. This alone probably wouldn't have been a deterrent, however, there was another issue to consider. To maximize the head space in our lofts we chose a shed roof with a low pitch. Cedar is not recommended on low pitches - below 4/12 - because it has a tendency to leak. This could have been remedied with an added waterproof membrane underneath the shakes but this remedy would add to the cost and weight of an already expensive roof. While cedar is a bit lighter than asphalt shingles they lose most of this advantage once wet because they have a tendency to absorb moisture. According to the calculations I made during the decision process, at best we may have saved 200 lbs of weight if we had chosen cedar but we saved over 1000 lbs by using the Smartsiding. We finally decided not to use cedar when we recognized that the combination of the low pitch and shed roof meant that we wouldn't see much of the roof anyway.

Aimee was taking pictures while I was filming....

The next consideration was a metal roof. These are popular for a few reasons; they are durable and tend to last longer than cedar or asphalt. Sometimes, after many years, they may start to leak at the gaskets of the screws holding it in place but the screws can be easily replaced with new ones which extends the life for many more years. Metal roofs are often used for water collection. On a larger building this would be a huge plus but our roof is only about 200 sq. ft. so the amount of water we would be able to collect would be minimal. Additionally, width restrictions during transport meant that if we installed gutters we would probably need to remove them for travel. Metal roofs are also known to be noisy in heavy rain or hail and while this would have been acceptable to us there was one other big drawback; with metal you have to put strapping on the roof and then the metal is corrugated and between these two things we would have lost about 3" of head space in the lofts. The maximum legal height for a trailer in our province is 13'7". We had to consider that any extra thickness in the building materials would have to be subtracted from usable interior space.

The drawbacks of both the metal and cedar roofs are the strengths of asphalt shingles; they are inexpensive, easy to install and they work well on low pitches, especially with the rubberized membrane we used for additional leak protection. Most importantly, for us, they were by far the thinnest option. We were much more concerned with having an extra 2-3" of head space than we were with the small bit of extra weight we would gain by using asphalt shingles. So while they aren't trendy, asphalt shingles were the best option for our needs.

The Installation Process

The first steps to shingling the roof were to lay down the waterproof membrane which is commonly called ice and water shield, however, in my industry it can be called by various brand names. The product is a rubbery, sticky membrane with a peel off backing and it is recommended as added protection on low slope roofs like ours. The next step was to install the starter shingles on the bottom and sides of the roof. The starter is needed at the bottom so that the first row of shingles has something to overlap and will prevent leaks at the seams.

Left: The first material I put down was the ice and water shield. Right: Starter shingles on a bottom corner of the roof.

Here you can see how I lapped the ice and water shield over the trim. I did this on all sides of the roof so water would have no chance of getting behind our siding.

The chimney and roof flashing for our small wood stove. I later redid this section of the inner and outer roof to increase its fire resistance.

Carrying shingles up a ladder isn't as easy as it might look. That bundle of shingles is 80 lbs!

When installing the shingles, I used a stair stepping pattern. This is important so the seams between shingles aren't too close to each other. I find that the easiest way to do this is to precut the shingles into sixths and stack them into piles in order of the longest to the shortest. Use full length shingles until you reach the top, then use the shorter pieces and repeat the process.

Note the stair steps and pile of shingles of decreasing length at the top corner of the roof

The shingles were each secured with six, 1¼" roofing nails. I used a nail gun, but for a job this size nailing by hand wouldn't have been too bad.

Left: The top edge of the roof was finished with a metal flashing called termination cap. Right: Notice the detail on the chimney flashing. I put an extra piece of metal on top of the flashing so I could get away with cutting the shingles back farther than normal. Inside the roof, I built a box of cement board between the trusses for the chimney. It's nice to know that even if a chimney fire were to happen our house won't catch on fire!

The finished product! You might notice that the house is in new surroundings but that is for another post.

Roofing Video

In this video, I go into a bit more detail of how I installed the shingles on our tiny house.

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