How to Install Siding & Trim on a Shed

This is the part where the shed starts coming together. If you happened to miss another part of the shed build, be sure to scroll down to the bottom of this post to find that info. But let’s get back to how to install siding and trim on a shed.

HOW TO INSTALL SIDING AND TRIM ON A SHED

Before I list all the materials we used, I wanted to talk about the type of siding. We decided to use LP Smartsiding because of how easy it is to install and cut. Please note that this is not a sponsored post. The other siding we were thinking about using was a cement siding. But it was heavy and required a certain saw blade. This would make it difficult to install. So we picked the LP Smartsiding.

Disclosure: This post contains some affiliate links for your convenience, click here to read my full disclosure policy.

MATERIALS:

LP Smart siding (comes in 4’x8′)
4″ composite trim
2″ composite trim (optional)
2-3/8″x.113″ exterior galvanized ring shank nails
house wrap (if using sheathing)
1″ plastic cap nails for house wrap
window flashing tape (optional)
caulk
paint and primer
sill nosing weather strip
#8 3/4″ lath sharp screws
vent

TOOLS:

circular saw
Rip cut (optional)
framing nail gun
Jigsaw (optional)
air compressor
chalk-line
tape measure
pencil
miter saw
razor blade

You can print the material list and instructions below.

Something to Note: I would recommend that you read the install instructions on whatever siding you are using.

INSTALLING THE SIDING

If you used sheathing on the shed walls, the first thing you should do is add house wrap. This is a plastic that helps to keep water out. Use a razor blade to cut the wrap and nail into place with a hammer using the 1″ plastic cap nails. Here is what ours looks like.

SIDE NOTE: We did wrap the openings with the house wrap by a couple of inches.

Something we decided to use was window flashing tape for the doors and windows. Because this is a shed you do not need this but again it is to help keep water out.

If you are installing any vinyl windows you will want to install them now. The wooden windows we used were installed after the siding. SIDE NOTE: There is a metal piece, called z bar flashing, that can be added around doors and windows. This will help with water. We used one piece on the bottom of each window and it will hangover the siding! Here is an example of how we installed our wooden windows. We put 1×2’s around the window, nailing the 1×2 to the framing, then nailing the window to the 1×2 (we used finishing nails for this).

Now it’s time to add the siding. The LP Smartsiding has tung and grooves to help with the install. But before adding them to the wall let’s talk about cutting the siding.

You may need to cut the length of the siding and you will want the siding to overhang the floor framing by at least 2″ but not more than 4″. We again used the circular saw attached to the rip-cut to make this cut.

TIP: Any cut you make on LP Siding needs to be primed before painting.

Once the length is cut, the siding can be added to the wall. Starting on one corner of the wall (place the first piece). This corner will have the groove side of the panel. Then attach the panel just like the siding company recommended.

THINGS TO REMEMBER OR TIPS:

attach using the correct type of nail and attach to a stud (2×4)
be mindful of the tung and groove. Too close to the groove could create you a problem
use a chalk-line to help you know where a stud is. We actually marked each siding panel before installing. This way we knew exactly where the studs were.
Use a hammer to hammer in any nails that are not flush with the siding or slightly indented.
Remember every nail and seam will have to be caulked before painting. So use enough nails but don’t go crazy.
We precut all window and door opening with a jig saw before installing but this can be done after.

Something that needs to be added is soffit to the roof overhang. We decided to use all the scrap siding pieces for this but you can purchase LP Smartside Soffit from the store. We install ours the same way as the siding but on the roof overhang!

LET’S TALK ABOUT THE DOOR

Now that the siding is added we need to talk about the door before adding the trim. If you will be using a regular exterior house door, you will not need to worry about this. But if you are building the door, like us, this is something you need to do.

1) Add a sill nosing weatherstrip to the door opening. This will help protect the floor and edge of the siding when moving things in and out of the shed.

We had to cut ours down to the right length and overhang to fit our shed (we added it after installing the trim and this made us cut the overhang part). We did this with tin snips but I would recommend not cutting the overhang if you do not need to.

To attach the sill, we pre-drilled 1/8″ holes into the metal. Then using the 3/4″ lath sharp screws attached to the floor. Here is ours after the install and months of use!

2) Next, you need to mark at least 1″ away from the door opening (the bottom could be different because of the metal sill).

TIP: Mark the top and bottom of one side then use the chalk-line.

This line is where the edge of the trim will sit because the door will sit on the siding here.

INSTALLING THE TRIM

Now that the door is prepped, the trim can be added. The trim we used was the same type of material as our siding. So we used the miter saw to cut them and the same type of nails to install them. Things to note when adding trim:

Trim needs to be installed so water can drain correctly. Here is an example of the cuts around a window.
On wall corners, one trim piece will overlap the other (makes an “L” shape).
Remember the nail holes will have to be filled in. So make sure they are slightly indented or flush with the trim.

FINISHING TOUCHES

Once the trim (and windows) are added, its time to fill in the nail holes and seams with paintable exterior caulk. Want a tip on applying caulk, see this post.

When the caulk is dry, prime any exposed cuts on the siding and trim with primer. Then start painting the shed. I started with the trim!

Also, we used Behr Premium Plus Ultra Exterior in White for the trim and French Silver for the panels. I used 2 coats for each! When the paint was dry, we installed the fascia (we talked about this in the roof post) to the side of the roof that is not covered. This is a metal piece that covers the 2×4’s and is installed by pushing under the drip edge then attached using screws (we used the 3/4″ lath sharp screws).

We also decided to add a vent to the shed to help with air circulation. We used the jigsaw to cut the opening (smaller on all sides than the vent). Then we attached with screws and caulked around using clear caulk.