Spray foam pipe insulation

You don’t want that foam off gassing inside a dwelling. Fiberglass is the standard for many good reasons even though it’s a pain to work with and clean up the fibers.

There’s a high cost to being cheap. Do the job properly or you will regret it.

Unprotected spray foam is a serious fire hazard, and most codes do not permit its use in an occupied space without fire resistant cladding. Some formulations not only burn well (they are excellent high temperature fuels) but also emit very toxic fumes in the process.

There is a difference between "inexpensive" and "cheap".

I'd think you need to build a form around the pipe, no?

the foam that comes out of a spray gun is what you want, like the insulators spray overhead. That gets applied on any plane.

Tiger Foam is one brand of a spray kit, looks like a barbecue tank, comes with a hose and spray gun.

. I'd check with the manufacturer about a specific application like that. Temperature, outgassing, flame spread, etc.

Yep. It's cheaper to use foam. Just don't complain to us if you can't sell the house (no mortgage) because exposed foam won't pass inspection by any competent authority.

Common misconception that a basement is not part of your conditioned space. It is near impossible to build in such a way as to truly sperate the two, never mind with what you see in a typical setting with maybe some batts in the ceiling. This means any heat in your basement goes to heating the rest of the house.

If you want to actually save energy, air seal the basement. Replacing the old leaky single panes and air sealing the rim joist was night and day in terms of temperature and comfort. Much better use of your money and time.

Don't know about steam but with hot water, unless you need it to even out distribution, don't bother insulating as it won't save you fuel. Enjoy the warmer basement and the indirectly heated floor for the main level. With hot water heat, when I had the old pipe insulation remediated, left the pipes bare. Turned the basement into a much more pleasant place to work.

P.S. Most firefighters consider spray foam liquid gasoline. Something to keep in mind.

what are you planning to use to cover it. Foam needs to be covered with approved 15 minute fire barrier.
Fiberglass insulate is in range of $3-6 for 3’ section depending on size. My go to source is: http://www.buyinsulationproductstore.com/

use that foam on your foundation sill areas instead

I'm curious to see the results. Seems like it will work. My only worry would be how it looks to be honest. The finished appearance is very important as it is a sign of a thoughtful professional. I've been in cellars where the HO has covered up all the mechanicals making it extremely hard to trace wires and pipes. As a fire fighter I know there's nothing in a modern that won't kill you when it burns and everything burns. As you mentioned, furniture carpets finishes etc. That's what SCBA is for. Like I said I'd worry about the appearance.

Calling someone stupid isn't necessary or helpful.

But I am genuinely curious to see pictures of the final results.

Grenfell Tower Block

This is commonly done and is considered a best practice.

For those concerned about fire risk and off gassing, how is it any different?

With the advent of air to water heat pumps residential hydronics used for cooling is becoming more common. Insulation of the piping becomes more challenging, because it's not just for efficiency but to keep the pipes from sweating. Fiberglass is useless for that, as the insulation layer needs to be air tight. For straight sections of pipe neoprene is good, but for irregular fittings it seems like spray foam is the best choice.

The big issue is it makes future service difficult as it conceals what's underneath and it needs to be chiseled off.