Insulation, Radiant and Vapor Barriers - Insulate ceiling between 1st and 2nd floors?

So here's my issue. Our house is about a 20 year old colonial style in the mid atlantic area. We've lived here about three years and the upstairs (2nd floor) bedroom floors are cold in the winter, even with the carpet, the carpet is cold. Last year I had the following replaced on my house; all new windows and doors, roofing, gutters etc, and new insulation backed vinyl siding.

Even though I didn't replace all of that because of the floors, I figured it would make a difference. It did make a difference in the feel of the rooms but the floors were still cold. Bathrooms floors are freezing.

My guess for the problem is that the rim joist butt right against the brick facade that completely surrounds the first floor (all 4 sides) and there isn't any insulation in the joist cavities. My initial thought was to drop the drywall ceilings (at least around the edges of the first floor rooms below the effected rooms) and insulate.

But due to all of the nice crown molding the previous owner installed on the 1st floor, I was wondering if it was a better idea and possibly more cost effective to pull back the carpets in those rooms on the 2nd floor pull the subfloor along the outside walls, insulate and reverse the process rekicking the carpet. What do you think? Please let me know if this makes sense to anyone with more expertise on this subject than myself. I have no problem doing the work myself, I just don't want to do it if it won't make a difference.

Thanks in advance,
CB

From my own experience, it is probably your plumbing chase the cause for the cold floor. Go into your attic and find the plumbing vent stack. It should be located above your bathroom. In the floor of the attic you want to seal around the vent stack. This is referred as the "Attic By-pass Phenomena". I would do this first before ripping up any floor or ceiling.

Thanks for the suggestion, I will check the sealing of the vent stack. Do you have any thoughts on the bedroom issues? The bedrooms in question are not too close to the bathroom.

The volume of air within a confine remains constant. What that means is, if air is leaving through your vent stack a volume of air equal to that volume of air must enter the confine. The air leaving is known as "Air Leakage" and the air entering the confine is known as "Air Infiltration". Furthermore, you cannot have air leakage without air infiltration and vice-versa. We can deduce from that one can reduce air leakage by reducing air infiltration and vice-versa.

Applying this to your situation indicates that the source of the cold floor in your bedroom is air infiltration. Which would be easier to address, tearing up the floor or ceiling to reduce the air infiltration or sealing around the vent stack to reduce the air leakage?

This follows Newton's third Law of Motion, "For every action, there is an equal and opposite reaction".

Following your logic, which makes perfect sense to me, I've noticed warm spots in the hardwood floors I installed in the hallway, underwhich is a bulkhead housing a supply duct. If that ductwork has major leaks or if the return is equally as poorly fit together it could easily suck in fresh air thru the joist voids and "wha la" cold floors. So maybe my best bet would be to address the ducts and if for no other reason than to quit heating voids.

Hey there.

Sounds like your home may not be holding heat well in general. Here's some thoughts:

1. Go around the house and check to see if there are loose spaces around wires, pipes, vents, and other external lines that run into the house. If so, take some caulk and carefully seal off areas like this. I've read that all these holes combined can equal the width of a basketball if combined.

2. Check your windows. Install storm windows in the winter especially and make sure they're forming a solid seal. 30% of the heat in your house is lost through the windows. Installing some nice vinyl double thermopane windows with a Low-E rating isn't as expensive as it sounds, and it's definitely less messy than dealing with drywall dust. If you have the money, splurging on windows with argon gas between the panes is great as well.

3. Insulate your attic. Heat rises in your home and leaves through the attic. TONS of heat is lost in a poorly sealed attic. Take care of that and your whole house will be warmer.

4. Insulate the basement and seal the crawl space. If you have a vented crawl space, then as air leaves the attic, cold outside air is coming in through the vents in the crawlspace to fill the gap. Installing a good crawl space vapor barrier can do wonders. The best on the market can be found here, as well as a lot of good info on them, especially in the learning center: noads.com

I'd try those solutions before ripping the house up and making a mess of everything. This is easier, better for the whole house, and will save some head room in the house.

I've heard of that phenomenon referred to as "the stack effect".

The volume of air within a confine remains constant. What that means is, if air is leaving through your vent stack a volume of air equal to that volume of air must enter the confine. The air leaving is known as "Air Leakage" and the air entering the confine is known as "Air Infiltration". Furthermore, you cannot have air leakage without air infiltration and vice-versa. We can deduce from that one can reduce air leakage by reducing air infiltration and vice-versa.

Applying this to your situation indicates that the source of the cold floor in your bedroom is air infiltration. Which would be easier to address, tearing up the floor or ceiling to reduce the air infiltration or sealing around the vent stack to reduce the air leakage?

This follows Newton's third Law of Motion, "For every action, there is an equal and opposite reaction".