I don't have a place for a punching bag in my home. I wrap my hand in a cloth or a bandage and practice my kick boxing punches on the wall, along with knuckle push ups. My master told it isn't good for bones.
I concur with the previous answers - punching an immoveable surface is bad unless your knuckles and wrists are already conditioned. For example I frequently do single-knuckle strikes on doorway framings - while I do it considerably harder than the normal person I still don't do it with anything near the power I would use on a soft target.
I would strongly suggest you find a martial arts shop (even if it is online, or even eBay) and purchase yourself a sprung makiwara that can be mounted on a wall, like this one:
Be aware that while these are good for conditioning (I used one for a number of years), they are reasonably noisy so may bother the neighbours if you live in an apartment.
My master told its not good for bones.
and he is right. Practicing "non-sport" karate (bushido dzen) I am following a simple rule: hit soft with hard (like a punch to stomach or strike to throat) and hard with soft (palm-strike to the head can cause lots of damage if done right). Of course, if/when you wear gloves, everything will be different.
It's not good for your body. It's also not good in general for your mental development. Walls and people don't move the same way. People yield* when they get hit. Walls do not.
Attach heavy pillows to the wall with velcro or glue or nails or something. Then punch those instead. It's a start, until you find something better to punch.
YIELDING - the mechanics and distance of punch are different on a target that yields. Punch a bag/body and the energy goes into the target, punch a wall and the energy stays in your fist. (taken entirely from a comment by user 'craig').
It is not good to practice on walls especially if you are just starting out, this could hurt your wrist. Knuckle push ups are not bad since there is no kinetic energy transfer between you and the floor. There are pads that you can purchase which can be attached to the wall, and provide some level of cushioning for your punches outside of the cloth or bandage that you currently use.
from: wall punching pads
In general, one can do that, but as always, it depends. Also, with something as immobile as a wall, one needs to act with even more control, care, and moderation than usual.
It also greatly depends on what martial art you perform and what your training goal is. For replacing a punching bag in kickboxing, I'm inclined to say "no, don't do it".
In Wing Tsun, the "normal" punching bag is a 6-7cm thick jute sack filled with dried peas (or something similar) fixed on a wall. I've been training on this for years without adverse effects, and I know dozens of people who have done likewise.
The "wall bag" works perfectly well for making the typical constant flurry of punches faster, and harder, and at the same time training your wrists.
However, you have to account for the fact that the way you punch in WT is totally different from the way you do in kickboxing. I would doubt that a "wall bag" works comparatively well (and comparatively safely) here.
You're applying an order of magnitude more force into each punch, and that same force acts, according to Newton's 3rd law, on any involved joints (including your spine). A "normal" punching bag that swings back takes away some of this abuse, the wall does not.
Hang a sheet of paper from the ceiling (wedge the string that it hangs on into a light fitting). Practice hitting the paper flat on, with a snap and speed (after warmups and stretching).
This will improve your speed, balance and accuracy without the need for equipment.
After you've done that well enough (500+ punches) do some strengthening stuff (pushups etc) for a few weeks. Then try the paper hitting again.
You can also use it for kicks.
There's a lot involved in hand conditioning. You can punch a wall, if you do it right (much better after some conditioning time). As your knuckles make contact with the wall, press your knuckles into the surface as hard as you can. This will help with deep-conditioning, not just the surface where you would see a callous.
I punch trees of many different sizes; I like ones that will move as I hit it. It is always better for you if the object you are hitting gives and not you. You can use an old phone book to strike, or a stack of newspapers tied with twine together.
If you know a fireman, try to get a few pieces of old firehose (looks like canvas) and wrap around a tree or mount to a wall or board. Lastly, a rubber mallet works very well, is quiet and portable! Just strike your knuckles with it throughout the day. Only do 40 strikes at a time to avoid breaking of the skin from over doing it. I am 63 years old, in the Arts since I was 10. I use 2 inch boards for my breaks while most everyone else uses 1 inch. I do 3 NOT spaced for a punch! I hope this helps.
You simply could use an old car tire, cut it in half and would have a nice punching bag you can put on the wall. And you would not hurt your hands that much. Please see the following:http://homemadegymstuff.blogspot.de/2009/11/car-tyre-tire-punchbag.html