Sealing up the metal flashing behind my recessed rad?

somekindofpress

Hey guys. Just moved into my house a few weeks ago. I noticed at times that I'm getting a stale basement smell near the recessed radiator (sunrads). It's right next to my bed and drives me nuts. At first I thought it was just when it was windy out, but I smelled it last night again and it wasn't. So I'm at a loss why I'm only smelled it at times, but, regardless, here we are.

I was thinking of just siliconing any gaps I see/where any metal overlaps, but there are two problems with that. One, it might be something behind that actual rad. And two, it might be coming from where the pipe comes out of the floor.

Should I have someone come in, remove the rad, put new airtight flashing over the existing one, and put it back?

Any ideas? Thanks!

hot_rod

Like a damp basement smell? You might check into where the smell is coming from and try to eliminate that also. Damp basements or crawl spaces promote mold growth.

If you have any air leakage where the rim joist connects to the foundation for example. The cold air hits the warm structure and you can get condensation.

Maybe contact a HVAC company to run a blower door test to find the leakage. Silicone and spray from cans are good ways to seal up.

somekindofpress

Luckily it's not damp. It's just that old house smell. We just had our 1970's finished basement demo'd before we moved in. It's bare concrete and Drylok'd now, thank the lord.

STEVEusaPA

Are you sure it's not rotting critters?

JUGHNE

Cooked and reheated mice have a distinct aroma.
Just hard to describe.
More desirable in the dry stages than wet.

somekindofpress

No, thankfully, it doesn't seem to be bbq'd rodent. I had the same smell in my old basement and in the attic in the last place I rented. Just that old wood smell. It's not the worst. It's not even bad, per se. It's just not something you want wafting into your nostrils while you watch TV in the bedroom, ya know?

JUGHNE

If your basement is all open, you could look under that radiator for openings and seal from the basement. The piping holes would draw a lot of air flow if the temp difference is high.

In very old houses sometime openings were purposely cut under rads into the basement for "fresh air" flow into the room.
Some even had openings to the outside for "real fresh air".

somekindofpress

Makes perfect sense, as I JUST found a half inch gap with cold air flowing over one of the new basement windows (my contractor was terrible, I'm finding out). It's two floors down, but directly under our room, and maybe 4 feet over. I'm guessing it's the cold air finding its way up? I thought heat rises, but I'm guessing any air might? I don't feel a cold draft. Just smell it. But I'm sure that could be it? The air difference would be gigantic. 20-30 degrees outside and 70 in here.

I texted the contractor and he said to use spray foam. I'm going to bring in another handy guy I know and get his opinion. For now, I used packing tape to seal off 95% of the draft. I'll see if that works with the smell.

hot_rod

When the do a blower door test, they pressurize your home and use a smoke pen to find all those air leaks or passages. This method can find hairline openings.

What about the door to the basement? Is it sealed?

somekindofpress

That's pretty awesome. The house if rom 1928. I'm sure every inch of the house will have smoking billowing through.

The basement door is not sealed. Not even close. I can see through the gap. The problem is that this is happening two floors up in the bedroom, on the opposite side of the house.

JUGHNE

You may have "balloon framing". The wall studs could be 20' long and extend from basement sill plate to attic with no horizontal "fire" stops in the vertical space. If no insulation that air could move from basement to 2nd floor constantly, and more so if you had a heat pipe inside the stud space.