Bat House Assembly Parts and Dimensions
Bat House Parts - Quantity - Dimensions - Material Type
- Roof Panel: (1) 16" x 5" x 3/4" - Cut at a 30-degree angle along its longest side - Exterior or Marine Grade Plywood (Not Pressure Treated)
- Back Panel: (1) 28" x 16" x 3/4" - Exterior or Marine Grade Plywood (Not Pressure Treated)
- Sides Parts: (2) 19" x 2" x 3/4" - Cut at a 30-degree angle at the top of each piece - Pine
- Front Top Panel: (1) 16" x 113/4" x 3/4" - Cut aa t 30-degree angle along its longest side - Exterior or Marine Grade Plywood (Not Pressure Treated)
- Front Bottom Panel: (1) 16" x 51/2" x 3/4" - Ceder (See lessons learned as this material choice is critical)
- (Not Pictured) Front Bottom Lip Panel: (1) 141/2" x 11/2" x 3/4" - Pine
- (Not Pictured) Mesh: Cut to size as needed
Tools
- Table Saw
- Miter Saw
- Drill
- Commercial Stapler
- Caulking Gun
- Paint Brush
- Tape Measure
- Safety Glasses
Caution: Some of these power tools are very dangerous and should only be used by an experienced adult. Please ask an adult for help with cutting the parts for your bat house.
Supplies
- Wood Glue: Titebond II Premium Wood Glue - Interior/ Exterior Use. Used for assembly and sealing of wood end grain.
- Caulk: DAP Dynaflex 230 Exterior Paintable Caulk. Used for caulking seams and front panel assembly
- Exterior Grade Screws: Deckmate 1 5/8". Used for the assembly of all wood parts.
- Staples: Arrow #T50 17/32" Staples. Used to staple mesh to bat house parts
- Mesh: Everbilt Hardware Cloth Black Plastic 1/2" Square Mesh Opening. Used to line the interior back panel and top front panel.
- Paint: Sherwin Williams Duration Exterior Latex Paint. Used to paint the exterior and interior of the bat house. (You can use any other high-quality, exterior-grade latex paint.)
- Countersink Drill Bit: DeWalt #6 9/64". Used to predrill and countersink all the screw assembly holes.
Assembly Methods and Considerations
Precut All of Your Parts First
If you are making more than one bat house, it is best to cut each part you need one after the other. For example, cut all the back panels for each bat house, then move on to the next part; this will minimize resetting of the power tool settings. This will improve the consistency of the parts from a dimensional perspective.
The power tools used to cut these parts are very dangerous and should only be used by an experienced adult. Please ask an adult to help cut the parts for your bat house, and always use safety glasses around power tools.
Predrill All of Your Assembly Screw Holes
To make the assembly process go smoothly, I recommend predrilling and countersinking all of your screw holes. I used a DeWalt #6 9/64" countersink drill bit. It drills the hole and countersinks it all in one step. Note the line drawn on the picture to the right. It is drawn 3/8" from the edge of the bottom front plate shown. This will ensure that the screw goes through the center of the side part of the bat house, which is 3/4" thick.
Sealing All Exposed Wood End Grain
Based on the lessons learned from the bat houses I built five years ago for my Silver Award Project, I highly recommend sealing all the exposed end grain of your wood parts. The end grain of wood is more porous and prone to moisture absorption, leading to potential swelling, warping, and deterioration over time as seen in my lessons learned picture. This can impact the life of the bat house and make it unsuitable for bats. This is what happened with my backyard bat house.
To protect the end grain, you can use a high-quality wood sealant or wood glue that is water-based, non-toxic, and safe for bats. I recommend and used Titebond II Premium Wood Glue, which is water-resistant and non-toxic. I applied the glue thoroughly on the end grain surfaces with a sponge paint brush, ensuring that it penetrated the wood's pores. Two application coats may be needed as the wood grain really soaks up the glue. This will create a moisture barrier, protecting the wood from the elements and extending the life and sustainability of your bat house.
Back Panel Layout for Assembly
The back panel for each bat house was made from a 28" x 16" piece of exterior grade plywood that is about 3/4" thick.
Note the pencil lines drawn at the bottom and top of the back panel. This is where the body of the bat house will be assembled. The bottom line is drawn 5" up from the bottom of the rear panel. This will be the bottom of where the side pieces will sit. The 5" area creates the landing area of the bat house on the back panel. The top pencil line is drawn 25" from the bottom of the back panel and is where the roof of the bat house connects to the back panel.
Predrill two countersunk holes on the left and right side of the panel 3/8" from the edge from the rear side of the back panel (two holes on each side). These holes will be used to drill into and secure the two side pieces of the bat house with assembly deck screws and glue.
Side and Roof Panel Assembly (View 1)
Side and Roof Panel Assembly (View 2)
Side and Roof Panel Assembly (View 2)
As noted in the parts list above, the roof panel and side pieces are cut at a 30-degree angle. This slope is essential to provide and help water runoff from the top of your bat house. I do not recommend making your bat house with a flat roof as water and snow may pool on top of the bat house and more quickly degrade its life and sustainability. Make sure to seal the roof panel's exposed end grain and the side pieces' exposed bottom end before painting.
Side and Roof Panel Assembly (View 2)
Side and Roof Panel Assembly (View 2)
Side and Roof Panel Assembly (View 2)
The left and right side pieces were attached to the back panel with two screws on each side, as noted above. The roof panel was attached to the two side pieces with one screw each. All the parts were also assembled with the wood glue recommended in the supplies list. Note the caulking used where the top of the roof panel meets the back panel. This is critical to help provide a durable, water-sealed joint at the top of your bat house.
Caulking the Interior Assembly
To help further seal the interior of your bat house from moisture and water, I recommend sealing all the interior joints with caulk. I recommend using an exterior-grade water clean-up paintable caulk like DAP's Dynaflex 230. Allow your caulk to dry completely before painting your bat house.
Painting the Back Panel and Interior Assembly
Once your glue and caulk have dried overnight, you are now ready to paint your bat house. I recommend painting both the inside and outside of your bat house. Bats living in your bat house can generate a lot of moisture that could quickly degrade your wood if it is not protected with high-quality exterior-grade paint. I recommend using Sherwin William's Duration Exterior Latex Paint. An excellent exterior grade water-based paint should last at least 8 to 10 years, depending on location and conditions.
Note that I painted the bat house without the front panels installed. At this point, you should also paint the interior side of the front top and bottom panels, as they will be assembled to bat house later in the assembly process.
Adding Mesh to Your Interior Assembly
Mesh is incorporated in a bat house's design so that bats can cling to it when they land on the bat house and can cling to it once inside. If wire mesh is used, it's crucial to choose a safe type that will not pose a risk of entangling the bats. If wire mesh is used, please be sure to cut off and file down all the sharp edges. I recommend painting over the mesh to add an additional protective coating to prevent rust. Remember that sharp metal edges should be avoided so your bat house does not harm its inhabitants.
As an alternative, I have found that plastic mesh is easier and safer than metal chicken wire mesh for both bats and the people assembling the bat houses. You still have to ensure there are no sharp edges, even when using the plastic mesh I recommend. As noted in the picture, I made sure all the sharp edges were cut off the mesh. See my supply list for the type of mesh I used and the staples I used to attach the mesh to the back panel and the top front panel.
Final Assembly and Paint (View 1)
Final Assembly and Paint (View 2)
Final Assembly and Paint (View 2)
Now, at this stage, you are ready for the final assembly of your bat house. At this point, all of your bat house parts should have been painted on all sides to ensure that they are well protected from moisture and water to help prolong the life of your bat house.
At this stage, you will assemble the top front, bottom front, and bottom front lip of the bat house. Given that the surfaces are already painted, you should use caulk instead of glue on the joining surfaces when screwing these parts to the bat house side pieces. Note that the bottom front lip is connected to the bottom front panel by two screws.
Final Assembly and Paint (View 2)
Final Assembly and Paint (View 2)
Final Assembly and Paint (View 2)
You're almost done! Once all the pieces have been assembled, it's time to check all the joints to ensure they are well sealed. Caulk any open seams to ensure your bat house is well protected from the elements. Once the caulk is dry, you can touch up the paint where needed.
Congratulations, you are done! Did you remember to build more than one bat house to donate to a local school?