[asmi]

I am renting a recently renovated 1950s home in northern California. The LVP flooring is always cold and uncomfortable. Kitchen tiles are even more so. Temperature drops fast and heater kicks in frequently, more so than any place I lived in. My landlord got two different insulation professionals to check the home. One said attic is the issue. The other said attic is perfect but the subfloor needs to be insulated -- crawl space insulation is not very common in this area considering the relatively warm weather here.

Our ceiling is never that cold. Floor always is. Can we go with the second guy? Or it is better to get someone who employs thermal cameras to determine the issue?

 

[XSleeper]

The ground temperature is typically in the low 50s year round. When its cold out it may be warmer in the crawlspace than it is outside. But if there is no insulation, it would stand to reason that the floor would also be inclined to be closer to the temperature in the crawlspace than it is to "room temperature"... which is the temperature where your thermostat hangs on the wall. Also, warm air rises, cold air sinks to take its place. So no matter what the thermostat reads, it will always be colder on the floor... insulation or no insulation.

That being said, I don't know why one professional would say the attic is "perfect" while the other says it is "the problem". I would find out the reasons why one thinks it's perfect... and the reasons why the other thinks its substandard. My guess is that one thinks topping off an attic (regardless of whether it needs it or not) will be some fast, easy money. Easier than being on his back in a crawlspace.

Regardless, its the landlord's decision.

 

[Bud9051]

In addition to attic insulation air leakage from house to attic is bad as outside air must come in to replace it and as stated that incoming cold air goes right to the floors. So yes the attic can be contributing.

But air leakage is often a combination of a few big leaks and many small ones, here is a guide.
https://www.energystar.gov/ia/partners/bldrs_lenders_raters/downloads/TBC_Guide_062507.pdf

One of the problem with cold floors is they have no source of heat. Warm air in all rooms is pushed to the ceilings by the colder aid which falls to the floors. That leaves the only source of heat to be radiant energy from all warm objects above but that heat is quickly lost to the crawlspace below.

Bud

 

[AllanJ]

If the same number of dollars worth of additional insulation will result in less overall room heat loss when installed in the attic then the ceiling guy would win. But the subfloor guy would win in terms of achieving a higher floor surface temperature.

 

[XSleeper]

I'm not sure this is a situation where just throwing more insulation at the problem will help. If you live in a cold and windy climate, then yes, insulating the floor might help the floor temperature.a lot. But if the floor is, say, ground temperature (50s) insulation may only raise that temperature a few degrees, because as Bud mentioned, the floor has no real good heat source- heat goes up. And bare feet aren't going to notice much difference if the insulation only warms the floor 5 degrees... to say 60F.

But if the floor temperature is closer to outdoor ambient temperature (lets say low 40s on a cold windy night) the floor may be closer to 40 or 45F due to the wind carrying that heat away. In that case, insulation in the floor might seem to help more... but only because raising the floor temperature to that same target of 60F is now a 15 degree difference. Possibly much more noticeable to the touch.

So its possible a FLIR could help, but imo an infrared thermometer might be all that is needed to find out what temperature your "cold floor" really is. Because if the floor that you are complaining about is really only 55 degrees or so, I'm thinking that insulating the floor will be spending a lot of money to only raise the floor temperature a few degrees. (Maybe only 5F) and you will be disappointed in the results.

Insulation alone does not keep things warm when heat rises. The BEST way to warm the floor would be to insulate the exterior walls of the crawlspace, (not the floor) also insulate, encapsulate, and cover the ground, and then introduce conditioned air to the crawlspace. Then you would be pumping heat into the crawlspace which would then rise up through the floor, keeping it as warm as you like. (70F or so.)

 

[asmi]

Thanks for the suggestions. Will look to get FLIR or infrared thermometer.

Noted:
"The BEST way to warm the floor would be to insulate the exterior walls of the crawlspace..."

"But the subfloor guy would win in terms of achieving a higher floor surface temperature"

"That leaves the only source of heat the only source of heat to be radiant energy from all warm objects above but that heat is quickly lost to the crawlspace below"

 

[Nealtw]

If you are used to living in a house with a heated basement or apartment building the floor will always feel cold.
if you can't live with that find a different place to live.