I don't think I would use a UTH with a wooden viv. A UTH would not conduct enough heat through the wood and placing it inside the cage could prove to be dangerous.
ok thanks what if i stuck it under some glass insidethe viv then it wouldn't cause burns
Putting it under glass won't prevent burns...you can only do that with some sort of device that controls how much heat it puts out, such as a thermostat or rheostat. The problem with putting them INside a cage is fire and electrical risks. Just putting a piece of glass over the top of it would not solve either of those...and it could still cause burns if not controlled.
would a ceremic heating bulb (with guard ) be appropriate
I know you don't want to hear this....but honestly, I wouldn't. Although, if you could get it set up correctly, you might be able to pull that off. The critical thing is to make sure that the snake can't touch the heating element AND to make sure that the "guard" doesn't get too hot, either. So...if you can have enough space around the bulb that it won't heat the "guard" too hot.....and, if you can be absolutely sure the snake can't get through the guard....it might work.
your best bet for a homemade wooden cage is a radiant heat panel. they are pretty expensive, but you have to factor that into the cost of building it. using a CHE with a guard would work, but it's not gonna keep the cage at ideal temps. you could use some flexwatt and seal some plexiglas above it, but that would be a lot more work.