I built a simple single plane shed style roof at a low pitch. Simple to construct and still effective for the needs of the tiny house roof. The roof would include 2 foot overhangs on the ends and 1 foot overhangs on the front and back. To create the pitch of the roof I built an extension wall on the front side of the house. Building the tiny house roof comes after finishing framing the walls.
How did I frame the extension wall?
My next goal is to build the extension on the front wall to create a pitched tiny house roof. Currently all four walls are 8 feet tall but the extension will add 1.7 feet of height onto the front facing wall including the bottom and top plates. This will make the front side of the house 10 feet tall. When roof joists are laid from the front to the back this will create a pitch that will be the roof.
Framing the extension will be similar to framing the regular wall. I did it in two 12 foot sections to make it easier. The extensions have a 12 foot bottom plate, 12 foot top plate and studs placed 24” on center. Each 12 foot section has framing for two small pop vent windows that are 7.75 inches tall by 23.25 inches wide. Small but cute and effective. I evenly spaced the pop vent windows so they were symmetrical.
Framing for pop vent windows
The framing of the pop vent windows is the same as the framing for the regular windows. Two jack studs holding up a 4×6 window header that is directly supporting the top plate of of the extension. Since the window is 23.75 inches wide I framed the jack studs 25.25 inches apart to include a 1.5 inch gap.
I framed the first section of the extension and got some help lifting it on to the front wall. The 12 foot extension lined up with the 12 foot section below it and then I nailed it in. I then framed the second section the same as the first. We then lifted the second 12 foot section onto the wall and I nailed it in. I then nailed the two 12 foot extensions together for extra strength. Now the extension is complete and we are ready to move onto roof joist framing!
How do you frame roof joists?
My tiny house roof was very simple to frame as it was one flat surface at a relatively low pitch. I laid 10 ft pieces of 2×6 lumber across the front extension wall and the 8 foot back wall. The roof would have 15 2x6s. To attach the joists to the walls of the house I cut notches in each roof joist. I was able to mark where to cut the notches by laying the 10 foot pIeces into place.
I would then mark where the notch would be relative to the walls. The roof joists were to be laid 24” on center and inline with the framing in the walls.
How many roof joists do I need for a shed style roof?
| House length | 10 Feet | 15 feet | 20 feet | 25 feet |
| 16″ on center | 12 | 16 | 19 | 23 |
| 24″ on center | 9 | 12 | 14 | 17 |
The tiny house roof I designed has 2 foot overhangs on the 8 foot sides and 1 foot overhangs on the 24 ft sides.
It is important to have overhangs as it will keep rain from damaging the siding of the house. For me it was less relevant because I was choose metal siding. However if you are using wood siding you will want to have larger overhangs than 1 foot.
Start laying the roof joists
Before you start measure each one of your 2×6 roof joists and make sure they are all 10 feet long . I started by laying the 2×6 joists between the extension and back wall. After laying out the 2x6s make measurements on each piece where to cut. Make sure your measurements are correct for 1 foot overhang on the front and back side of the house.
I then made notch cuts in each roof joist that was 4 inches wide as the top plate it will be resting on is 4 inches wide and 3 inches deep. I made these notch cuts in 13 of the roof joists as 13 of the joists will rest on the walls and the other 2 wont have notches as they will be overhangs. If you make the cuts correctly the roof joist should slide into place over the top plate of the extension and back wall.
Nail in the roof joists
After sliding each roof joist into place and making sure they were 24” on center I nailed the roof joist into place. I nailed the joists into the extension wall and back wall. I added hurricane brackets to the front and back of each joist to further reinforce the strength of the roof from high speed winds. If everything was done correctly the roof joists should all line up with the ends even with each other on both the front and back sides.
To create the 2 foot overhang on both sides you want to nail two 14 ft 2x6s to the end of the roof joists. These act as rim joists similar to the framing of the floor joists. This will create 2 feet of rim joist that hangs past the last roof joist. You want to nail these rim joists in to connect the roof joists on the front side and backside of the house. From the end of these overhanging rim joists you can nail in the two last roof joists.
Ready to lay sheathing
After nailing in the end roof joists you should have 15 roof joists total. These joists will create a flat surface from one end of the house to the other end of the house. They are spaced 24” on center and have two 2 foot overhangs on either side. You can now prepare to lay the roof sheathing over the roof joists to create the roof!
How do you sheathe a tiny house roof?
Sheathing the roof is the same process as sheathing the walls. You want the edge of the 4×8 sheathing board to line up on a roof joist. Remember to nail every 4 inches through the sheathing into the stud of the roof joist. What I decided to do was to install the sheathing running lengthwise with the house. I also staggered the seams to take an extra precaution against water intrusion.
This meant for the 10 foot widthwise there would be three rows of sheathing. The first row would start with a whole sheet of 4×8 sheathing. The second row would start with a piece that is cut in half so that would be 4×4. This will ensure the edges of the sheathing are continually staggered down the row with the first row. The third row is the remaining 2 feet of width as 2 rows are 8 feet wide. This third row will start with a piece that is 2 foot wide and 8 foot long. This will ensure the third row will have staggered seams with the second row.
Working down row
Once you set up the beginning of the rows everything lines up down the row perfectly staggered.
Work down the row installing full 4×8 sheathing pieces on the first two rows and 2×8 sheets for the third row. At the end of the three rows you will install a 4×8 sheet, 4×4 sheet and 2×8 sheet to complete the sheathing. I was now done with the sheathing of the tiny house roof.
How do I water seal sheathing?
I used huber zip system sheathing so the vapor and water barrier is already built into the siding. You must tape the seams between the sheathing sheathing sheets and cover any nail penetrations. This will ensure the entire surface is water and air tight.
How do I water seal huber zip system?
To water seal and vapor seal a huber zip wall you must use huber zip tape to cover the seams. The tape must be applied with a special roller that makes indents. Making these indents in the tape starts a chemical reaction that creates a bond with the sheathing.
How do I cut the openings for windows and doors?
After standing up the walls with sheathing on them you will need to cut holes for windows and doors. The holes will be cut where the sheathing covers the window or door framing. For each opening I started the cut with a circular saw and then finished cutting with a jigsaw. Cut the sheathing all the way to the edge of the framing.
After cutting all of the window and door holes you will be ready to move onto the next phase.
Conclusion: How do I build a tiny house roof?
The end product should be a house that is completely sheathed and covered in a vapor barrier. The next step will to be install windows and doors in the tiny house.
Next Step: Add Windows and Doors to the Tiny House
More resources: https://www.tumbleweedhouses.com/roof-shapes/