easily detatchable wood joints

just use 2x2 pieces across the width on the underside of the board, to fit on either side of a beam

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>>1089196
Like this? Seems good.

Though my concern would be torque flipping the board if the cat was on the edge of it.

Maybe I could drill some holes in the 4 corners and tie a loop of string around the beams.

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>>1089199

>>1089200
Any reason to put it both sides? Just doing the insides would have the same effect?

The reason i ask, is because the planks I have are pretty much the exact distance of the rafters (no overhang).

>>1089196
>>1089199
>>1089200
Also, another concern with this design is that the planks could still slide on the rafters.

I'm thinking of sticking some rubbery material on the underside of ends for friction.

>>1089202
Then butt a board on each end and put the cleats inside that.

>>1089202
you could probably do it that way

I'd probably want something else going down/under the bottom of the beam to keep it tight....

another idea would be to use metal angle brackets on the inside, underside and then use C or vise clamps to hold the bracket tight to the beam

that wouldn't go anywhere

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>>1089209

>>1089211
A little too complex for my liking, and would look a bit messy.

Thanks for all the help though. Will just try keeping it simple at first, and improve as needed.

>>1089212
not really

the metal brackets would be attached just as the wood would be, and clamps would be much more secure

>>1089199
>flipping the board
Use heavier wood, and make sure that you extend past the edges as little as possible to prevent lever action.

It is also possible to make your slots deeper (as in, the height of the beams), so that it's impossible to insert or remove the device without placing it 100% perpendicular to the beams.

If you want a BIG, square-ish platform, then you can create the platform out of multiple long segments, hinged together like a garage door.

Because this is a bigger platform, if you add rubber to the slots, this increases static friction as there is more area and weight, which will make it less likely to slide along the rafters.

Make sure you keep weight in mind.

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>>1089189
How are these cats going to get up to these beam platforms anyways? It looks a little too high just to jump.

I also fear for the cats getting down . Firstly because the cat could hurt itself if it just wanted to jump down. Second because they could land on furniture beneath it and damage that as well.

I have a window shelf for the cats I take off every year for the AC. 6" wide and about 5' long
Hold it in place with 2 small nails(long but skinny). The weight is always pressing down so all the nails have to do is keep it from sliding.
Pops off easy and just hit the old nail holes to put it back. Been about 10 years and I think I need new holes next winter for the first time.

The plank would have to go on top and not overhang the beams though.

>>1089189
Your original idea could work, except cats have a way of fucking things up. Somehow, someway, someday your cat will jump off the board at a funny angle and end up kickflipping the thing through your window. Cats are crazy like that.

I say, just get the planks you want, cut to length, paint white to blend in, then get up there and screw them down into the beams from the top. You'll be able to unscrew them and remove them before the inspection, and no way will the inspector bring out a ladder to look for extra screw holes on the top side of the beams, where they're not visible from the ground.

Easy, 2 minutes with a decent drill and screwdriver bit, strong and secure, no need for extra cleats or rubber to hold them in place. Also, you can put them back up when the inspector leaves.

I liked the 1x1 idea. Just overshoot the width of the board by an inch then tie a rope around it and the beam. Not a permitted change so you wouldn't even need to take it down for inspection.

I have a cat who can walk forward and backward down a 1" wide railing, never fell.

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>>1089189
no need to dick around with screws wood

just drill some holes and tie it

the holes can be small, you dont even need a big rope, just some paracord should be fine

>>1089189
OP just ask your landlord if you can install a hanging ceiling.

it will make it more fun for the cats, sure they are sure footed and could walk on the support strips, but if they step on the panels its hello terrified kitty and pray to god that the cat doesn't land on you.

>>1089199
this but add a few slim nails.
i doubt you landlord will be inspecting the top of the beams. if he does, hes a real piece of work