Bat House Forum

[Terry Lobdell]

Here is an experimental box where I covered the front with tread from some old steel belted tires.

[Terry Lobdell]

It was hard to judge the length of tread needed as you can see by how uneven the bottoms are, but each piece flattened out nicely with drywall screws every 2" down the middle....
The front boards I attached vertically and gapped them for ventilation on the lower part........

[Terry Lobdell]

I mounted this box by partially constructing it in 8 basic componants and then attached them one at a time onto the pole using french cleats to hang the larger sections.

Shown here is the back section. It is gapped between each board in the lower half for ventilation and exit point purposes.

The horizontal strip near the top is a 22 degree french cleat to hang the next baffle section onto.......however, I made a mistake because I wanted the back open all the way across for maximum ventilation which big browns love.........I ended up cutting a 3 inch notch in the middle to allow heat to escape out the top and also another entry/exit point for the bats....

[Terry Lobdell]

Here is the back before I had it mounted on the pole. You can see the gray french cleat strip from which the next baffle section will hang from.

You can also see the 45 degree french cleat used to hang this section onto the pole.

[Terry Lobdell]

Here is another view of the back mounted on the pole. You can see the gaps in the lower boards. Big brown bats love back crevices with lots of ventilation during hot humid weather.......

You can also see how the 45 degree french cleat locks the section onto the pole.

[Terry Lobdell]

Here is a view of the bottom half with the lower french cleat visible. The matching french cleat half will attach below for more support when finished. It will also act to extend the landing pad.

[Terry Lobdell]

Here is a view of the back of the next baffle section with the gray 22 degree french cleat strip attached.

Each baffle section has at least one gap in the boards to allow internal movement between crevices by the bats.

[Terry Lobdell]

A view of the next baffle section mounted. It was real easy to carry it up and just hang it onto the french cleat. 2 & 1/2 " drywall screws secured it tight to the back section.

The next baffle section would be mounted the exact same way.

The internal baffles boards are quaking aspen and the outside boards exposed to the weather are red pine.

[Terry Lobdell]

Here is a view from the back with the next baffle section mounted. This box ended up with 4 crevices. All internal baffles surfaces are just rough sawn wood with no scoring or saw kerfing. The only prep I did to them was to take a surform and knock of any burrs or strands of wood fiber sticking out too far.

[Terry Lobdell]

Here is a view from the other side. The pole is hollow made from 2 - 1x6 larch sandwiched around 2 - 2x6 larch for a 6"x8" finished dimension. It is very rigid. I angled the top 10 degrees so water can run off and covered it with some scrap alumunum.

This also shows a nice view of the french cleats......

[Terry Lobdell]

Here is a view with the side piece on. I stained it before I put it up. It is a 1"x8" larch board.

[Terry Lobdell]

Here is a view of the roof.......it is open in the back for ventilation and for an extra exit for the bats.

These pictures aren't the best, but the next one I do I plan on getting much better pictures showing the whole process of building a bat box like this.

[cloudman75]

Great photos Terry of the project bat house and the french cleats. Thanks for sharing them. The old tire material should
be a good solar collector and have a long life in the weather.

Frank

[Terry Lobdell]

Thanks Frank, the tire material actually worked better than I expected..........I plan on using it more for bat box exteriors.....

[Dave M]

Terry,
Great pictures and ideas. I'm looking for some advice from you though, because I'm very close to beginning construction on my own bat house. I'm hopeful of having a maternity colony of both little browns and big browns. My house will be built around the top of a spruce stump that I left over 20 feet tall in full sunlight, and the box will be in the neighborhood of a 40 inch cube. Each of the four sides will have 3 or 4 crevices, so it will have at least a dozen crevices in total. I plan to use kerfed boards, rough cut if I can get them, I may also have access to some weathered barn boards that are very coarse on one side. I'm considering a 5" landing pad, and crevices 37" tall and 36" wide, although the north side will be more like 24" wide. The crevices will have varying widths (3/4", 7/8", and 1"). I'm thinking of making the north and east sides more ventilated with the wider crevices, and the south and west sides narrower with less ventilation, hopefully providing good places for both species. The center of the box surrounding the trunk and the attic above the crevices will be a single sealed air space which I expect to get hot during summer days. This hot space will provide heat through the wood to the inner crevices, while the outer crevices will be cooler. I plan to have black shingles and paint the box black. I think the interior hot air space should not go all the way down to the bottom of the crevice, but rather stay 1/3 to 1/2 way up from the bottom, so that it only heats the top portion. I'm also thinking of painting the top half of the sides black and the lower half of the sides lighter for more heat variation. I will build a frame using 2x6's and 2x4's surrounding the top of the stump, then I will use french cleats to attach each side, and finally add the roof.

I want the roof to be low with a shallow slope to minimize size and weight, how much slope do you recommend if I use tar paper and shingles?

Do you think the interior heat chamber will get too hot and that it should have some kind of vent?

How wide should the gaps between the boards be to allow big brown bats to move between crevices within the house?
By the way I'm also going to have vertical gaps about 6 inches high in some of the corners to allow bats to move around the house, from the east side to the north side for example.

Given a 3 foot crevice height, how high should I place the horizontal vent on the outermost crevice, and how wide should the vent be? I'm thinking about a foot high and 1 inch wide.

I'll have vertical vents on the ends of each crevice too, I'm thinking about 6 inches tall and as wide as the crevice, any idea on how high I should put them, or if they are about the right size?

Once this main house is up I want to attach a smaller house beneath it on the north side. This smaller one will be for use in hot weather, it will be painted a light color, have tremendous ventilation, and 7/8" or 1" crevices. How wide and tall do you think this should be? I vaguely recall that I believe you had a bat house mounted on a chimney where big browns occupied the cooler space between the box and the chimney.

I hope I didn't bog you down with too much detail, and any advice will be appreciated. Of course anyone else please chime in too, I just picked on Terry because I've found his posts about big brown bats very interesting.

Thank you,
Dave