Bat House Forum

[flyin-lowe]

If you have read my other thread you know I am building a large bat house for a friend. I think it is going to be 4'x4' 5 chamber. I am going to use exterior grade play wood for the baffles. Like the one I already built I will use strips of 3/4 boards along the outer edges to make the gaps the correct size. With a 4 foot span I though I might put a partial strip of 3/4" board in the middle to assure the gap stays the same all the way across. I read somewhere that sometimes the pups use a "shelf" or ledge to roost on. Would it be a good idea to put a strip horizontally across the middle of the baffles? This would help keep the gap consistent but it would also provide an internal shelf. I wouldn't make it go all the way across obviously just maybe alike an 8 inch long piece running horizontally. What do you think????

[Terry Lobdell]

You could do that but a lot of guano will accumulate on top of it.....definitely spacers are a good idea.........I have some older bat boxes with plywood baffles that I need to put some spacers in to readjust the crevice thickness..........

Maybe you could have the spacer run at a 45 degree angle so if guano does accumulate it could more easily be swept out?

[flyin-lowe]

I didn't think about the guano. Do the pups need something to help them or will the other bats keep them steady? I can't remember where I read that at I just remember reading the the pups need something to rest on when very young.

[BioColonel08]

I personally have never heard that pups need a ledge to rest on, but as long as it isn't harmful to adults I'm sure you could add a resting platform. I would absolutely make it either sloped or grated. I personally like the grated idea because it allows urine and guano to fall through but pups could cling to it. a sloping board would mostly likely still soak up urine and decay much faster than the surrounding wood.

I know this doesn't really answer your question, but I too am concerned about pups falling out of my bat boxes. I added a pup catcher to the bottom of my box. It doesn't stop them from falling out, but it greatly reduces the mortality rate of pups that do fall out. You can check out how to make one at the link below.

Hope this helps and good luck!


https://batworld.org/bat-house-pup-catcher/

[Terry Lobdell]

A pup catcher is a real good idea.........I have a site where I have a problem with big brown pups falling out each summer........Kent Borcherding says it only happens when they are overcrowded and I would have to agree with him.......

The link from batworld is a real good design.........I might make the bottom part a little bigger though........

[flyin-lowe]

Well I got started on the bat house this afternoon. It is going to be 4'x4' and 5 chambers. I am building it similar to the 2x2 I built a couple weeks ago with a few modifications. I am going to make the roof flush with the top of the chambers to help avoid wasps. I have drilled two 7/8 inch holes in each baffle to allow access between cavities. I have also used a small spacer in the middle as I found the wood was sagging a little. I used 1/2 exterior grade plywood and didn't think it would sag any but it was so a small spacer in the top and bottom will keep the gaps even. I made it pretty small so it won't collect too much guano. Again like the last house I used a cut off wheel on my air compressor and scored the surface of all the plywood to grip. I know I built it a little back wards from the way most people do but it worked out good last time. I built the baffles first. Then I ripped the side boards to make sure they were exact for a good seal and finish. I knew if I tried to start with the side boards first like many do my math would be wrong and I would end up with a cavity that was either to big or too small. This way I have 5 chambers all the exact same and I will rip a 1/8 to fit. Then put the roof and sides on and it will be done. It is going to be a very heavy house. My friend is going to use 2 telephone poles to mount the house to. I had a local saw mill give me a bunch of wood to use for the front and back. He gave me some cedar but it is pretty thin. My plan is to cover the front with that since it won't have any weight on it. He also gave me some rough cut pine that is about an inch thick. I will use it to cover the back so it will be sturdier when mounting.

[flyin-lowe]

I forgot to ask. So my friend knows what would the capacity of a 4'x4' 5 chamber bat house be? More then likely he will attract little browns.

[William Bagwell]

Over 2,000 based on Franks (very conservative) 4 cubic inches per bat. My math: 48" x 45" (allowing for side strips) X .75" X 5 chambers = 8,100 cubic inches / 4 ci per = 2,025.

On vacation all next week, hope to make a bunch of progress on my plastic houses.

William

[Markcuda]

Great job on the house
Keep them pictures coming

[flyin-lowe]

Well I got about an hour this afternoon to work but I didn't take any pics. I have all the chambers done and started putting the back boards on. That is kind of a slow process because I am using rough cut lumber straight from the saw mill. I am getting it as close to square as I can by hand. The good news is I don't have to score all of those boards because they have a really rough surface. I wish I lived further south were I didn't have to paint it. It is starting to have a nice rustic look with the rough cut boards. The board I am making my back boards out of is at least 12 inches wide, maybe wider I never did measure it. Maybe I can get some updated pics tomorrow after I get off work.

[cloudman75]

Great photos, good looking work. You might consider ripping the side boads, attaching them to the baffle spacer boards with a few screws, and then run your front and back boards all the way across the side boards. That would eliminate the vertical crack like you had last time to fill in. Also the bat house would be stronger perhaps and less leak prone.That's how most bought houses are built. When you get through, please weigh the house. I'm betting on close to 100 pounds or maybe more finished. Interesting project and like William calculated should give 2000 plus bats a good home without being over crowded.
Just a thought from a guy who can't even build a bird house right.

Frank

[flyin-lowe]

I got some more work in today. I got all the back boards on. I had some mix and match rough cut lumber straight from the saw mill. It is one inch thick stuff and thankfully it is rough enough I don't have to score those pieces. The landing plate is 4 inches from the bottom of the baffles. I also put a gap all the way across the back for ventilation and plan on doing the same across the front.
I got it flipped over (no easy task and am ready to put the side boards on. If I build another I will take your advice and run the front and back boards over the side boards. I wasn't sure what size lumber I was going to use as I got three different stacks of stuff from the saw mill. I got some cedar I might use for the front but it is pretty then. I also got a pile of poplar but it looks pretty old. It had been stored in a shed but a few pieces felt week. I am going to go through it and see what I think. The poplar is about 3/4 inch thick and the cedar is under 1/2. It is pretty flimsy. I don't think it will matter just being on the front but I am not sure yet. I also think I am going to use 2x's instead of 1x's for the two side pieces so I have more meat to hang this thing with. I am not yet sure what plans he has for attaching it to the 2 telephone poles. If anybody has any ideas please feel free to chime in. These pics aren't' very good, as I figured out after the fact one of my kids had fingerprints on the lens of my little camera.
It's hard to tell from the top view but the top baffles are each one inch shorter from the back to the front so there will be a slope on the roof.

Here is a picture from the top.


Here is a shot from the bottom.

[Terry Lobdell]

Good idea to use 2" stock on the sides.......

I would give the cedar a try in the front........half inch is thin but cedar is very weather resistant.......and the thinner stock heats up faster in the morning.......shouldn't be too hard to replace if needed in the future........

popular is good species for bats to grip onto because it is fairly soft and has a good texture when rough sawn........

My choice would be cedar in front and popular in back.......

[William Bagwell]

Terry, how well does popular hold up as an interior baffle?

Going to start a new thread with a longer version of this question...

William

[flyin-lowe]

I already used the pine on the back (and one piece of cedar if you look closely). I know pine isn't the best but the price was right, it's one inch thick, and it will get a good primer and paint. I will try the cedar but it is way out of square. I will have to see how much trouble it is to square it up. The poplar is already pretty much square, I think it is actually pieces that were taken off of an old barn or something. So far using the left over screws I have from the first house I only have about $40.00 in this beast. I am going today to buy some more screws and a couple of 2x8's for the sides.