We are ready to add tiny house siding after the house has been sheathed, covered in a vapor barrier and in my case covered in a layer of external insulation.
I chose to add 30 gauge corrugated metal sheets to the outside of my tiny house. This metal sheeting made up the roof and the siding. These sheets came in three lengths 8’, 10’ and 12’ and were all 26” wide. I chose this because corrugated metal is durable, light, easy to install, affordable and I think it look pretty good. I then finished off the metal siding with wood trim painted accordingly.
The process for adding tiny house siding will depend on how you designed the house. There are two options, installing siding on a house with internal insulation or external insulation.
How do I install tiny house siding with internal insulation?
If you installed the insulation internally between the stud bays, the process for installing insulation will be rather easy. The siding can be installed directly to the sheathing by identifying where the studs are located. Make sure to mark on the sheathing where the studs are located. It should be apparent by the previous nail holes where the studs are located.
How do I install tiny house siding with external insulation?
Personally I went with external insulation to increase insulation performance and eliminate the need for drywalling to cover up internal insulation. When installing the external insulation I installed vertical wooden battens to hold mineral wool batts to the side of the house. These battens were 6” wooden strips that were screwed directly into the studs of the house to securely attach them.
The framing of the house has the studs spaced 24” on center so naturally these battens are also spaced 24” on center. The corrugated metal sheets will be screwed into these wooden battens to create the siding and roofing of the house.
The external insulation sticks out from the house so it was necessary to install L shaped metal flashing around the windows and doors. The external insulation butts up against this flashing. This flashing covers the reveal of the external insulation. During installation of the siding the metal sheets will be installed right up against this metal flashing and will be covered with trim after.
How many pieces of corrugated metal do I need for tiny house siding and roofing?
| Square footage | 150 SqFt | 200 SqFt | 250 SqFt | 300 SqFt |
| Sheets of Corrugated Metal | 42 | 48 | 54 | 60 |
How do I install corrugated metal siding on a tiny house?
If you are installing corrugated metal sheets the process is rather easy. The sheets are 26” wide so the idea is when they are installed the width is 24” wide but with an inch of metal overlap on either side. This is perfect because my wooden battens are spaced 24” on center so the 26” sheets fit perfectly.
The corrugated metal is wavy and the ends of the sheets easily lay on top of each other. You want to install the sheets where the ends of the metal sheet lay over or under the next sheet. When you install the sheets you will also lay a bead of roofing sealant on the 1” overlap and then lay the next sheet over this bead of sealant. This will ensure a water tight installation and will glue the sheets together.
Fascia
For my house I had an open fascia where the studs of the roof stuck out. This means it was necessary for me to cut notches in the metal sheets so the siding went all the way to the roof. I did this by placing the metal sheet up agains the house and seeing where the notches needed to be cut. I marked the notches with a marker and cut the notch with tin snips. The studs of the roof were 2x6s so the notch had to be 1.5 inches wide and 5.5 inches deep.
How do I get started installing corrugated metal sheets?
I started on one end of the house and worked my way down laying the overlapping ends of each sheet on top of the other. It doest matter which wall you start on. Since the house was 24’x8’ there were 12 sheets needed on the long part of the house and 4 sheets on the wide part for the tiny house siding.
Lay each sheet up against the house one by one to see what cuts needed to be made. Use the tin snips to make the cuts then lay the piece in place against the house and screw it into the wood batten underneath. Hold the piece in place against the house with your knee as you drive metal roofing screws through the metal sheet. Install screws every 2 feet up the metal sheet from the bottom to the roof to secure it in place. Use a high powered drill.
How do I water seal corrugated metal siding?
Every sheet must have roofing caulk applied to overlapping parts. The screws should also be covered by roofing caulk as well. I chose to cover the screws with caulk only on the roof part because that is where there is the most risk for water intrusion. The caulk was messy looking so I didn’t apply it to the screws on the visible walls.
How do I make cuts for windows and doors?
Eventually you will run into a window or door. The process for cutting a window or door notch is the same as cutting the notches for the stud. Lay the sheet up against the house and you can see where the L shaped flashing that surrounds the window and doors is touching the sheet.
Mark with a marker where the window or door touches the metal sheet and then cut the notch with tin snips. This may take multiple attempts to get the hole cut right. Don’t worry if you over cut the metal sheet as any gap will be covered with trim later.
Place the sheet with the notch cut around the door or window and screw the sheet down to the wood batten.
How do I make cuts for slanting walls?
On the width sides of the house the wall slants up with the roof. To cover these sides you will need to cut the top of the sheet at an angle that will fit with the sloping roof. The way to do this is to measure how much rise happens over each 26” peice. For me there was a 7 inches of rise over a 26 inch peice.
To create the slanted piece I measured 7 inches down from the top on one side of the piece. The side that is measured 7 inches lower should be relative to the wall. Then use a marker to draw a slant from this marking to the top opposite corner of the sheet. This marking will be where you will cut to create the slant. Make the cut with tin snips.
Place the sheet up against the wall to check your work. If you need to adjust the angle make sure you use this adjustment for all future peices. Don’t worry if there is a small gap as this will be covered by trim later.
How do I install corrugated metal roofing?
I decided to use corrugated metal sheets for the tiny house siding and the roofing of the house. The process for adding roofing sheets is the same as adding siding except even easier. There are no cuts that need to be made for notching around windows, doors or studs. My roof was set up the same way as the sides of my house.
I had mineral wool batts laid on the sheathing of the house with wood battens holding the batts in place. The battens were screwed into the studs of the house and the metal sheets were screwed into the wood battens.
I started from one end of the roof and worked my way down laying the overlapping lip over the previous sheet. As before I added a bead of roofing caulk onto the overlapping part before I laid the sheet down and screwed it in.
My roof was 10 feet wide so I used 12 foot long sheets of corrugated metal. Its important to leave a bit of a lip of metal roofing extending out from the roof on the bottom side of the roof. This will ensure that rain will drip off and away from the house. However you don’t want the lip to be more than 2 inches as wind can get under it and cause stress on the roof.
How do I add flashing to the roof?
My roof was a very simple shed style roof so it didn’t need any valleys or ridge pieces. I did add 4”x6” L flashing to the sides of the roof and to the front of the roof. The sides of the roof are the part of he house that is 8 foot wide. The front of the roof is the part that is front facing and the highest point of the roof. I added flashing in these areas to stop from water intruding in. It also made the roofing job look more aesthetically pleasing.
The back part of the house doesn’t get flashing as it is where the drip edge of the roof will be. This is also where the bug screen from the external insulation will be so this area will remain open.
How do I install trim on tiny house siding?
After all the corrugated sheets and flashing is installed the last step is to cover the gaps with wood trim. The trim I chose was 1x6s for around the windows and doors and 2x1s around the roof line. I started by painting the boards accordingly to the color layout. Next cut to size the wood and started screwing them into the metal siding. I used 2” long construction screws to connect the wood to the metal siding.
Conclusion: How to install tiny house siding
The exterior of the house should be now complete other than the porch area. The siding on the tiny house should provide a waterproof and sun reflecting layer to the outside world. Next step is to start starting off the interior.
Next step: How to Interior Design a Tiny House
More resources: https://www.homedit.com/corrugated-metal-panels/