How to build a wall-mounted cat tree

We got a kitten for Christmas. His name is Hank. We wanted a place for him to get away from the dog (if he wants) and a place where the dog couldn't get his food. This is what I came up with.
By the way, the math I used to calculate the forces within the shelf is called engineering statics, because it involves calculating the forces within static structures or structures which are not moving. I’m a civil engineer for my day job, so I’m trying to bridge that into my hobbies and videos. If you’re interested in seeing more engineering concepts in my videos, please let me know in the comments. And if you think it’s a boring interruption to the project, let me know that too!
Music with permission by Jason Eddens (teddyandwendy.b...)

[@MakeSomething]

There should have been a "Math Warning" at the beginning of the video. :) Great project!

[@soleman62]

***** I'm a cat man, but I think that is an Awesome dog.

[@eileenschuller5309]

Not an Engineer OR a mathematician but your logic and process is a good reminder of all that needs to be considered. Very clever and cat-practical design.

[@tekobari]

You've given me the confidence to proceed with my project. My husband was astonished one day to come home to find I'd changed my entire curtain system throughout a rented house -- 24 windows. He'd bought a drill, and the hardware store wasn't far away . . . I was amazed at myself. But this catification project is 1,000 more difficult. Still, I'll start with three or four shelves and take it from there. BTW, I'm a cat behaviorist. That means I know more about cats than shelves. You need a cat scratching post at least 1.5 times the length of a fully-stretched cat to maximize her health. You're going to have to use more rope or carpet (I advise sisal rope) to cover the rest of your post. Scratching does several things: marks the area with the oils from her foot pads, which soothes her nerves; tears off shedding cuticle on her nails, thus sharpening them; and most important, stretches and strengthens their shoulder muscles. You'll notice that they stretch to within 3" to 6" of the top of the post, then pull their bodies using their body weight to add force and stress. It also loosens their ligaments, keeping them flexible. A cat's clavicles, unlike ours, are free-floating. Keeping that area "loose" is what allows them to sneak through the super-narrow openings that surprise us so much. "How the hell did she get out?" "How'd she get in the closet/suitcase?" They estimate the width of an opening by whisker length/width. They can always get through anything narrower than their whiskers, and usually less, depending on their build. Wily little devils.

[@gracelewis6071]

This is great information!

[@jackiek710]

As a mutual friend of the feline kind, thank you for sharing that to everyone. Anyone who brings a cat into their lives should aim to know as much about cats as possible. The sad truth is, most cats aren't provided with adequate care in general but especially when it comes to the attention and environments they require in order to maintain health and happiness.

[@theDudeOfDudes]

My statics teacher could take a few notes from you on how not to put an entire clasroom to sleep when calculating moments.

[@margasa7]

+TheDudeofDudes My point exactly. Ever think of being a math teacher in high school?

[@schneir5]

The dog at the end looks like he's pouting, like "He never makes anything for me"

[@matt_williams1015]

As a fellow civil engineer, I thoroughly enjoyed the statics explanation. Great project too!

[@soleman62]

Matt Williams As a fellow with not much more than good common sense, I appreciated that also. It is always good when someone thinks before they do. Great project indeed.

[@simondibbern5564]

I said this before and I say it again: I like your methodological approach to your problems. Your surprise math-attack certainly did add something new to the host of uniform build videos out here.

[@necroodin]

+Simon Dibbern lol i was laughing at t he comment, but was totally ambushed by the math ambush as well. Proceed into the Equational Jungle at your own risk! Great video

[@sharonhunter337]

The math attack, as you most hilariously put it, made me feel right at home. I grew up with a house full of engineers.

[@radicaicares]

Non-engineer here. Wood you get more strength out of the shelf if you made the side boards (boards running perpendicular to the wall) flush with the back board. So you are changing the load on the screws from pull out to shear. Just a thought, I really enjoy your videos. Keep up the great work! Chase

[@volalla1]

Chase Cares I thought that sneaking a pun in there and nobody wood notice?

[@beliasphyre3497]

(To the tune of I wish I were an Oscar Mayer Wiener) Oh I wish I were a three legged doggy, That is what I truly want to be, 'Cause if I were a three legged doggy, I wouldn't have to lift my leg to pee.

[@shelleytraz]

Step one: get a workshop with several woodworking tools and a knot tying resource.

[@caramonmajere447]

I'm impressed to see an engineer that can actually build something. It's a running joke in the construction industry that architects and engineers can draw, but not build a doghouse. I'm glad you're more than a "Clicker".

[@dizzeydaisy]

Caramon Majere and he didn’t have 5 guys standing around him supervising while he did all the work... another little construction joke.

[@GregdeJong]

Cats, shelving, engineering, carpentry, knots... I think we're long lost brothers.

[@heathermcgrath22]

I loved the engineering. Wish I would've known how cool that could be back in highschool. I really like the shelves too. Simple and functional.

[@sarahtlovesb]

I'm not an engineer and I really liked the math. It's great you included it. Can I ask you to elaborate how you got the pull-out force to be >60lbs? I'm familiar with Fsmax = UsN where Fsmax=Maximum force of static friction where if this is overcome the object will move Us is the coefficient of static friction and N is the normal force (mass x gravity). Is this on the right track and then you are somehow accounting for the force applied over the dimensions of the shelf?

[@2testtest2]

I realize I'm about 7 months late, but in case any one still wants to know, here is how this is calculated. The weight of the cat times it's distance from the wall gives a torque of 144"lb. For the shelf not to start rotating, the screws have to create an equal and opposite torque. Since the shelf can not move through the wall, and since the screws are trying to hold it in, the shelf will want to rotate about the bottom of the contact surface against the wall. The fulcrum of the screw upper most screw is much bigger than that of the lower screw, and so most of the strength comes from this one screw. So this screw has a fulcrum of 3". This gives the Equation at 1:35. Plugging in the numbers though, I only get a force of 48lb, which is a bit odd. It seems he has chosen a point slightly above the bottom corner, looking at the drawing, which probably gives a better, or at least more safe estimate, given that wood can compress a little. Anyway, that's the logic behind this calculation.

[@rachely.1222]

the carpet is hideous..

[@sharonhunter337]

The carpet is nice. He said his wife liked the carpet and this is her house, so perhaps you are not seeing that it perhaps matches some piece of furniture.

[@jjhernandez7728]

@@sharonhunter337 I doubt the cat mind's either , Bet the kitty loves it 🐱

[@sharonhunter337]

@@jjhernandez7728 looks very thick. The kitty can sharpen their claws. Agreed. Kitty probably loves it.

[@fireball5540]

thats an great idea but i think you could add a cat cave a little hideout for your cat to play hide and sleep

[@Ce2009ce]

Just found ur vid..love it..What a great kitty dad r u😊making those great looking shelves for your cute kitty..I wish I was as handy as u..but..I'm on a mission to get shelves up on the wall for my cute Coconut😊2..they love to b up high..

[@ReevansElectro]

I was hopeful that this was going to be: "Wall mounted cats."

[@Selyasa]

Hi, I like the technical info because I want to know how h why things work.

[@MsMelissaAnn]

12lb? My male is 18.9lbs 😂😂😂😂

[@MsMelissaAnn]

Oh, out houses are built out of cement and steel (Taiwan) We had two cats, but one recently passed, the male is lonely and losing weight (he was 21 lbs) so we are kitten-fying the house to find a new friend for the male (he adapts easily to new cats) Do you have screw recommendations?

[@megaibfernape3612]

God imagine being married to an engineer. I'm in the wrong degree!

[@nikolistreeter796]

LOVE THIS!! long time fan of the channel and was searching the tube for cat tree vids and found you had made one. Mind=Blown.

[@lukehanson5320]

Been a fan of the channel for 5-6 years and just saw this old video. Even 'Young Grady' was fun to watch/learn from. Gonna' have to catch up on all your pre-fame content now ;)

[@laineywright2696]

I gave you a thumbs up and was about to leave, but I decided to add a comment. I was very impressed with your engineering statistics added to the video. Most people don't care about such, as long as the video looks slick. I'm adding your video to my favorites because it is worth saving.

[@fryefoto]

I’ve been watching a lot of catification videos lately and yours is the only only to bring up the increased forces of the cat jumping onto the shelves. Thank you!

[@Eleahchris]

I love it and the cat looks like he loves it too.

[@shastakennmpx17]

Splendidly to see Woodprix have new plans which helped me save some money and energy for this construction.

[@fusspuss16]

cat's ownning it

[@phil8249]

You were concerned about pocket screws, then proceeded to use drywall anchors instead of going into the stud??

[@isaaco5679]

Where i actively encourage my terrier to chase and play with our cats. I also made a cat tree out of a large limb from my yard.

[@RiffRaffMama.]

Good video, but I was itching to take it off you and fix it when you folded the trimmed side of the carpet *over* the front! Tuck it under the front flap so it can't be seen, especially since your carpet has a one way pattern.

[@Гурд_Йовт]

Eba, что там за расчеты были, чтобы коробку к стене прикрутить🤨

[@jennifermedina6588]

Very talented and creative! Its perfect! Thank you.

[@rafekaren]

How did you attach the rope with the monkeys first to the ledge?

[@pen25]

one thing left out was proper use of glue. screws are only meant to hold the 2 together long enough for the glue to cure.

[@beliajkrouinc21]

If you want you can learn from woodprix scripts how to make it yourself.

[@trueleyes]

Way to go Doc. those were my exact calculations too, with a few short cuts on my part. It's about time we have a man of intellect on hand here on social medias' KZbin. BRAVO Professor.

[@Shadetreewoodworkerposts]

Nice idea. I have 2 cats that would love to get away from our lab/retriever.

[@user-pt1cz4ot1e]

Thank you so much for this. We are converting a bus to live in full time, and have 4 cats. I appreciate the math to make sure I don’t do something stupid and hurt my senior guys coming along for the ride. 💜

[@sharonhunter337]

Nice people. Doggie manners and unassailable kitty food. Well, very thoughtful people. These are things I wouldn't have thought of ....

[@greenearthblueskies8556]

Dayuuuuuuum...I just had a brain freeze...too much statistics 😂

[@H_A_L_7]

I subscribed after watching this video, my first time telling that I subscribed, I blame Mr JonesyBones below :) I want to do this for my two cats, fingers cross. Thanks for the inspiration, was looking at catriss (environmentally friendly cat furniture ...expensive) somehow ended here.

[@margasa7]

It´s true... dogs eat cats. But they only do it in the wild, when they are in packs. .... I loved your shelves! thankyou.

[@margasa7]

+margasa Forgive Nicola Gregson, she , like me, takes pride in being totally math challenged. But now, after your video, I wish I had payed more attention in math, or I wish I´d had a teacher that teaches me how to apply math in life. I´ve been depriiiiived :)

[@brassfieldzendejas806]

I know you can get solutions for that on woodprix website.

[@pomeranianchannel]

I can tell this man is a great person. There dogs has 3 legs. I have been there. I miss my 3 legged dog so much. They are so special!

[@sharonhunter337]

You read my mind about pull out and force, but I did not have the vocabulary, so thank you for explaining the engineering.

[@SwabLevy]

Awesome Video! Love the math and physics involved. Looks great. I couldn't tell for sure, did you design the top level as the food station as well? Very interesting idea. I would however separate the water from the food. In my experience cats prefer their water and food in different places. Also if the water is on the top level the potential mess would not be easy to clean up. Just my thoughts. Great project.

[@Cellottia]

Brilliant! This will surely keep your cat happy as it gives him a place of his own from which to watch all the comings and goings. He won't be stressed as he can get out of the way, and he knows he owns that bit of the house. Lucky cat: loved cat :-)

[@davidroeder5548]

I know this is an old video but if strength of the joint was so critical, why not use a more advanced technique of joinery; such as a dovetail?

[@axhed]

lol not surprised to find something like this on your channel.

[@youforgot2flush620]

No one wants math problems in a diy cat shelve video!!!!!

[@bibimarulanda991]

😢😢😢😢yo sólo quería hacerle una estación a mi gato, no pienso tirar cohetes a la luna

[@48cloudpierre48]

the rope is plenty long if you flip the wood and have it on the top half! cats like to stretch vertically when they scratch so having the rope on the top half would be plenty

[@dhanyoktaviany7029]

come for diy cat tutorial and get the math problems,

[@fredflintstone1547]

inspired! you've got skills. thanks for the video. I will use this when I rescue in the future

[@barretthageman3350]

Nice idea, I miss my furry pets, but I have learned to really love having fish for pets.

[@thehistoryoftheworld]

so what kind of screws should we use? also, no math necessary for the pullout resistance from the wall?

[@FerrariTeddy]

I actually like these more than the cat trees, because they are much cheaper to make, requiring less materials.

[@JMBBrasil]

Best thing you could ever have with you.

[@wendys390]

God bless you! It is heartwarming to see your pretty pets, and how happy they are, and how you did this out of thoughtfulness for them. Wonderful stuff, thank you.

[@jimmy5003]

Hi, can you please tell me what kind of pen you were using in the video.

[@RC_Engineering]

I absolutely love your videos, so I hope you dont take offense to my questions. Wouldn't it be more sturdy to just use a few corner plates for connecting the side that is going to be next to the wall? Also, why didnt you use glue to make the carpet adhere better to the wood? Lastly, I think it would be a little more asthetically pleasing to cut the carpet so you cant see any fold-over. Awesome concept though, and I think your cat is really cute.

[@JMBBrasil]

3:50 love the not! Would love to learn how to do it.

[@Leo9ine]

I love that this is in the Civil Engineering playlist. It's so wholesome

[@jetsonjoe]

First rate and love the math to explain why it needs to be properly engineered.1

[@nicolagregson6054]

Ya could have just said whack a big screw in for strength , ya didn't need to geek out on us . But nice job . And I want that kitty cat .

[@DoctorX149]

Kind of the point of the channel

[@checkitout2468]

So awesome 👏 👍😎

[@vijayvarghese1652]

love the math explanation. only thing i didnt like was the carpet pattern

[@DustinPrat]

Wow!!, I would love to do this for my cat but she's in excess of 20 lbs and the dog can jump 3 ft no problem, but the cat can only jump 0.5 ft

[@sharonhunter337]

Make stair steps. My previous neighbors, 30 pound, 15 yo cat lived on her dining room table. Rag doll, kinda ran the household. She made like a spiral stair case out of everything around, little box, bigger box, stool, something, then chair, then hamper, then something else. Kitty worked her way up there. She wasn't jumping for anything.

[@garybillington2239]

French cleats would work better.

[@johnconklin9039]

Nice project, pets, sketches and calculations! Man after my own heart, lol.

[@laineywright2696]

I loved your video because I have two of those, LOL!

[@niky7197]

I had 32 cats in my home... :D

[@sharonhunter337]

LoL

[@theyxaj]

How is your little Hanko doing now?

[@KrankyPandas]

Your channel is amazing. Thank you

[@jacklynchristani960]

We thank you, purrfect idea beautifully engineered.

[@GooseCrack]

Engineering and cats? Heck yea!!

[@jaspermartin7444]

awww you got a ball for christmas! Anyway. How much resistance force would you assume for two cats thudding on the shelves at the same time? Wish you had shown us exactly what kind of screw you used, and exactly what kind of hole in the wall, and how you attached screws to wall. I'm a newb and still not clear...

[@roccoVAL]

ohhh the subliminal messages in this one are endless

[@jaspermartin7444]

glad to entertain! (no idea what you're talking about tho, I really am ignorant when it comes to carpentry) I have two cats and for sure they would chase each other up and down any wall shelves they had access to.

[@maymaysama]

Your cat is sooo cute

[@thegirlcriedfashion]

Wish I had the tools for this!

[@Driving4bangers]

Good cat

[@ariefabdurrahman8898]

what is the size of the box?

[@allandocater6296]

Enjoy woodprix woodworking instructions.

[@stargarden2577]

Wholesome and mathematical

[@lookylooky100]

English please....only kidding...good job

[@sharonhunter337]

Cats can run 28 mph.

[@CatsOnTV]

Super cute kittens.

[@1tothe9thpowerreborn20]

I love cats and dogs

[@BrittKvan]

Really liked the engineering explanation!

[@Kqto]

Very cool idea and cute animals!

[@TonyBombardo]

Combining my two favorite things; cats and engineering! Great video

[@naeemakhtar5749]

واو

[@vicstee482]

Gorgeous kitten! And great idea.

[@barbaracole4314]

Lucky little kitty !

[@JMBBrasil]

Uau!

[@larrymccammon9687]

Great vid! Thank you!

[@BlairBryngelson]

1:37 giggity

[@silverseedcat]

❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️ love it, thank you

[@anoniem012]

I love you man

[@KindCreature1]

Very nice, thank you!

[@TinaPastore]

Cute video