Can the first story of a slab on grade be liveable in cold climates?
2-story SOG house in zone 4.
The downstairs is finished (fibreglass batt insulation in walls). The house is above grade on all sides. I believe no insulation under slab or perimeter (80’s build). New double pane windows.
No moisture/water intrusion from slab (taped poly for a week after heavy rain). No significant cracks, etc in concrete slab floor. Drainage around the house is good.
I had to post this because I’ve spent months trying to fix the issue using material online with no success.
Having reviewed a lot of the posts on the forums, I’ve checked:
1) No CO detected.
2) No significant amount of radon.
3) The living room on the first story has a gas fireplace. A thermometer reads 72 F while the fireplace is on. Ceiling fan is on to circulate the air.
Also, the forced air system (shared for both floors) has one return vent and several supply vents (all on the ceilings) spread throughout the living space.
4) I installed 1” EPS subfloor (Dri-core) and laminate so the floor is now OK at retaining heat.
5) Humidity measures the same upstairs and downstairs, 47%.
I read that most of the heat loss in a slab on grade is on the perimeter. Is this what’s causing the comfort issues? Is the first floor of a slab on grade a write off as living quarters?
I used an IR gun to measure some areas in winter: 55F on the bottom of the wall downstairs, at eye height the wall measured 60F, the floor with the fireplace on measures 62F. The bottom of the wall upstairs measures 68 F.
Replies
It sounds like the lack of insulation under the slab and around the perimeter in your 80s-built home could indeed be the root cause of the discomfort you're experiencing downstairs, especially in a cold climate like BC, Canada. This setup likely leads to significant heat loss, creating an uncomfortable living environment despite efforts to improve insulation and maintain consistent temperatures. Consider consulting with a professional to assess options for retrofitting insulation to improve comfort levels downstairs.
He says he's in Zone 4, that's the same as North Carolina, Tennessee, North Texas, parts of New Mexico, and Arizona. Hardly "a cold climate". It's like coastal Oregon and Washington too, warm and rainy.
Take the flooring up and put a ditra heating system in then put down a new floor should make a difference
I don't think the previous replies understood that your family feels sick while occupying the lower level in the slab-on-grade portion of the house...
If you feel sick while occupying the downstairs space, and this happens to all your family members, there must be a significant problem with indoor air quality (IAQ)! In addition to the CO and radon testing that you have apparently done, you need a complete assessment to understand the problem. In your cold climate, I'm going to guess that you have condensing surfaces where you have moisture and an environment that enhances mold growth, but that is just a guess.
The typical causes of poor indoor air quality are:
1. Mold: Mold spores thrive in damp, humid environments and can multiply rapidly. Depending on the type of mold, breathing air polluted by mold can make you quite ill.
2. Dust Mites: Dust mites are microscopic organisms that flourish in high humidity and feed on dead skin cells. They are commonly found in bedding, upholstered furniture, and carpets. Dust mites can trigger allergic reactions and asthma in sensitive individuals.
3. Pet Dander: This is composed of tiny, even microscopic, flecks of skin shed by cats, dogs, rodents, birds, and other animals with fur or feathers. Pet dander can cause allergic reactions and asthma symptoms in those who are sensitive to these allergens. I have allergies, and cat dander affects me in a short period of time... Do you have cats or dogs that are relegated to the lower level of the house? Or do you have carpeting in the lower level, and less carpeting or hardwood floors, etc., in the upper level?
4. Secondhand Smoke: Secondhand smoke from cigarettes contains over 4,000 chemicals, many of which are known carcinogens. It can easily circulate throughout your home, affecting the air quality and posing serious health risks, including lung cancer and heart disease. This should not be the problem, as you don't have the problem in the upper level and you didn't mention that there are smokers in the house...
5. Radon: Radon is a radioactive gas that comes from the natural decay of uranium in soil, rock, and water. It can enter homes through cracks in floors, walls, or foundations and build up over time. Prolonged exposure to radon can lead to lung cancer. Since you're experiencing sickness in short duration time periods, and the fact that you did some testing, it's probably not radon...
6. Carbon Monoxide (CO): This colorless, odorless gas is produced by burning fuels such as gas, oil, coal, or wood. Without proper ventilation, CO can build up indoors and cause symptoms like headaches, dizziness, weakness, and nausea, and can be deadly at high concentrations. CO concentrations could vary based on the useage of your fireplace and/or your forced air heating system. I would assume that your heating system is gas-fired, and that your water heater is also gas fired? Is that correct? How about a gas-fired clothes dryer? You could have outdoor weather conditions that could affect the proper exhausting of gas-fired appliances...
Anyway, I hope you are able to identify the problem quickly, and get this problem eliminated!
Thank you for the feedback.
No pets, smoking or carpets.
I believe mold is most likely from the options mentioned. Likely near the chimney.
I assumed mold would have a distinct smell which I’ve experienced before but perhaps not in this case.
Gas appliance are properly vented with outside air intake for furnace and proper exhaust.
Here's some more brainstorming on my part...
Since you and your family members all feel sick after a short time in the lower level, and you recover quickly with some fresh air, there must be something in the air. I think it would be money well-spent for a professional assessment of your indoor air quality...
Since the base of the downstairs wall measures about 55'F, you may have a condensing surface on your exterior sheathing, and and environment conducive to mold. Do you have cold air coming in at electrical boxes in the lower level? Do you know how the lower level exterior walls are insulated? Is this a seasonal problem where it disappears in the summer months? Can you cut a hole in the drywall to see if there is a mold issue (wear a respirator)?
Have you checked out the ductwork in the lower level? (I would think that if the downstairs ductwork was contaminated, that you would also have the problem upstairs.) Was the fireplace being used when you checked for CO levels? Do you have a "sniffer" for gas leaks? (About $32 at Home Depot: Home-Flex Electronic Gas Leak Detector.) I've tracked down gas leaks in three different buildings with that device, and only of of the three had people complaining of a gas smell!
Here's a link to a document on causes of indoor air quality issues, and conducting a walk-thru to assess possible/probable causes...
https://www.epa.gov/sites/default/files/2014-08/documents/sick_building_factsheet.pdf
The inconvenience experienced on the ground floor of a one-story house in a cold region may be due to insufficient insulation under and around the ceiling. Heat loss in these areas can cause cold spots and discomfort. Consider adding insulation to improve ground floor thermal comfort.
What in the hell is wrong with you?
Did you read the first or any post made here or do you think all you have to do is read the title?
It appears that the original post may have been edited or truncated. As of now (April 19, 9pm eastern time) there is no mention of a sick family, and it truly appears to be a question about maintaining comfortable temperature.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2796751/
Here's another link. One question that I haven't previously asked about your lower level: Do you have a garage on the lower level? If so, do you store any chemicals in the garage that could cause an increased level of VOC's?
Nothing stored in garage.
Drywall was moldy behind brick facade of chimney, working through getting that remediated. Hopefully that will resolve the issue.
Leaks at chimney penetration of that fireplace best be checked before you cover up the wall.
Thanks calvin.
Any thoughts on what to look for? I had one chimney inspection but they didn’t add anything specific except suggesting additional flashing.
A neighbor had a leak and said it was due to the “shoulder” of the chimney where it meets the house siding.
The chimney flashing at the roof is OK but its built to drip onto the chimney shoulder. The shoulder is black and mossy, some mortar is crumbling. Could it be just the sheet saturation of the bricks where the water is dripping?
Its a masonry chimney with no cladding.
I’ve caulked where the chimney meets the siding although it was fairly good. Siding is hardi cement board.
Thanks
Not being there I can only guess.
Generally, any sign of water or dampness on a dwelling is initially entering from above. Pretty scientific….
Flashing’s job is to divert water away. Caulk might be a part of the system but can also be the cause of the problem. That is, if you caulk a point of water exit then it can’t get in there but it also can’t get out.
So, your discolored brick on the exterior may be the place holding the water and moisture rather than the source.
Or not.
Maybe a good pictorial of both distance and closeups posted here will bring suggestions.
Sitting here in NW Ohio hoping for no clouds Monday….
Edit.
How does the chimney crown look? i.e., is there a flue pipe and slopping crown at the top?
Is the chimney shoulder the culprit?
Man, I’d really have to be there and think like water.
The chimney flash with the fasteners and what I guess is caulk and the upside overhang and how that might be detailed…..the black “flashing tape”? And the siding…..
Your guess is as good as mine.
Thinking like water, and you know it can wick its way uphill…….and of course can travel laterally and even then can change course at any junction……
A good flashing person might find it.
Also, what’s the crown of the chimney look like? Is there a good wash at the top?
Why is everyone saying he's in a cold climate? Three out 6 responses, so far!, have said he's in a cold climate. I'm guessing the fact he mentioned BC is the reason, but as I said above, Zone 4 is the zone in parts of or all of North Carolina, Georgia, Tennessee, Arkansas, Texas, New Mexico, Arizona, for example. It's far from a cold climate! Climate zone 4 means less than 3,000 heating degree days (HDD). Charlotte North Carolina's average HDD is a little less than 3,000, 2,875. Not a cold climate.
It looks like you're zeroing in on the root cause of a mold problem. From your pictures it's not obvious where the exact location of the water infiltration occurs, but I think you're on the right track, and I totally agree with the comments from calvin...
Can you inspect the underside of the roof from the attic? I'm expecting that some of the roof sheathing will be stained or rotted in the vicinity of the chimney. I'm also thinking that you will end up removing the shingles, replacing damaged sheathing, installing a stick-down membrane such as Ice and Water (that laps up the sides of the chimney), and reflashing/reshingling that portion of the roof.
The details that are most suspect in my thinking, are:
(1) The flashing that appears to dump rainwater on the "shoulder" of the chimney, resulting in erosion of the chimney. Possibly, the installation of a "cricket" to divert rainwater to the other side of the chimney might be beneficial. Also, is this side of the house oriented toward the prevaling wind, and are the shingle edges "glued" to each other? Wind-driven rain is particularly adept at finding small voids in roofing/flashing...
What is the width of the drip edge at the roof rakes?
(2) The caulking on the flashing at the upper corner of the chimney. You don't want to depend on caulking to seal a void in flashing... I'm going to guess that leakage is occurring at that corner...
(3) The intersection of the chimney with the siding. Can this area be inspected from the attic, or by cutting out a small piece of drywall?
(4) The diverter strip in the valley below the chimney that directs water toward the gutter. I would inspect that diverter and valley area carefully...
(5) Repointing/repair of the chimney starting with the crown and working your way down to the "shoulder", etc. (I would also install a chimney cap...)
I am on a slab zone 5 Northern Vermont, I put down heavy poly then 1" polyiso, 3/4 advantec then 3/4 hardwood White Oak - raised the floor temp 7-8 degf, doesn't sound like a lot but I assure you it's made a huge difference.
Sounds like a great improvement as a 7-8 degree F increased floor temperature does a great job with regards to condensation. For others with Fine Homebuilding All Access memberships, an excellent guide for finishing a basement (or a slab floor) is an article by the late great Andy Engel, entitled "The No-Mold Finished Basement". "Carpenter Andy Engel demonstrates a reliable way to make a basement comfortable and dry by insulating from the inside using rigid foam."
Based on your observations, it's possible that heat loss around the perimeter of the slab is contributing to the comfort issues. Additionally, the first floor of a slab-on-grade house may indeed experience challenges with retaining heat. Consider exploring options such as insulating the perimeter or adding additional heating sources to address these issues. Monitoring humidity levels and ensuring proper ventilation can also help maintain comfort throughout the house.