Radiator Heat

fuse_5

Hello, 

I live in a house that was built in 1974. I have hot water boiler heat for the house. In the crawl space area under the kitchen, I noticed that there is some darkening of the floor joists above a heat radiator (fins). Is there a distance between a radiator and wood that should be maintained for safety? Is there a danger of that joist combusting?  The joist is currently about 0.7 inches away from the radradiator.  I was going to take a sawzall and cut an inch or so off the bottom of that joist. What do you advise i should do here? See attached pictures.  Thank you. Sorry if i posted this in the wrong category. 

Jamie Hall

First, there is no danger of the wood combusting. What you are seeing is almost certainly simply dirt being deposited by air convecting over those fins.

Second, do NOT cut anything off the bottom of a joist. Anywhere, ever. At least without the advice of a structural engineer. The stiffness of a joist is related to the cube of the depth of a joist, and it looks to me as though that particular one has already been seriously compromised to fit the pipe.

pecmsg

Get a carpenter in to sister that joist up. 

The fins can be removed if in the way. 

JUGHNE

Is that joist cut at all?

mattmia2

Jamie Hall said:

it looks to me as though that particular one has already been seriously compromised to fit the pipe.

I think that is just wane.

mattmia2

But the stain is either just dirt in the air from the air convecting through the fin tube or some char from when that fitting was soldered when the element was installed.

fuse_5

Thank you guys for replying ... so just to clarify:

- the floor joist has not been reduced or tampered with. It's a 2x10 board the whole way. The bottom of it is just a bit "rough sawn"

- so it sounds like this black staining is just dirt and that I should just leave it be as is? It will not start my house on fire 😅? Do I need to do anything about it?

- is there actually any code or guide on how far these radiators should be from joists ideally?

Thank you all for your time helping me on this issue. 

bburd

There is no danger of fire there. The piping can safely be in direct contact with wood. The only reason we generally don't do that is because if the pipe rubs on the wood it will make expansion and contraction noises.

deanofsteam

The temperature of the water circulating through that "radiator" is probably not more than 190F from the boiler, and therefore not high enough to cause a fire. I agree that the discoloration on the joist is either from air convecting upward from the "radiator" or it's from the propane torch when the "radiator" was installed. I agree that you don't want to cut into the joist because you may compromise its strength. I use quotation marks around "radiator" because it appears to be a pretty crude guess-timation of a heat exchanger at best.

Big Ed_4

The marks are pollutants in the air that get caught up in the stream of the convection of the heating element staining the wood . Burning of wood , tobacco and candles would cause the ghosting ...

hot_rod

I wonder what the intention of that short fin tube is? Not much heat transfer without being in the metal enclosure to pull cooler air into the bottom.

Possibly just a joist warmer🧐

Big Ed_4

I was thinking the same , It is not in the crawl space , assuming the storage of Christmas ornaments just below it . Maybe they ran out of 3/4" copper . We all been there .

JUGHNE

I have seen bare elements hung at the ceiling in basements in North Dakota.

Also read of them put under CI tubs for a little warm up.

fuse_5

So just for clarification, the space is definitely an indoor crawl space ... we live in a tri level house and this space is below the main (middle) level and is accessed from the basement. It has concrete floor and is about 3.5 ft high used mostly for storage. There's a sump pump there too. There are 2 other fins down there spaced out equally so they definitely intended to put these in there to maybe provide some heat. There are a lot of water piping and electrical cables attached to the floor joist "ceiling". 

fuse_5

Thanks again for all the replies .. you put my mind at ease regarding the no fire hazard.