I just finished a house that took me two years to build and this is our first winter. The house is a modified post and beam and is completely open on the upper level. On the lower level it is open half way with beedrooms etc forming the support for the loft.I have 8 1/4 insullating panels on the roof with a vapor barrier under them as the mfg recommented.
My problem is that I get moisture where the upper and lower sashes of the windows meet.The colder it gets the more moisture. I have radiant heat between the floor joists in the basement. I have 2×6 walls and sealed the place really well when building it. The humidity hovers around 70 % which is too high and I realize it probably is the cause but I can think of no reason why it is so high. There is nothing in the house that would create abnormal humidity.
Any suggestions?
Mike McNally
Replies
You have a really tight house. And if you are living in it, you are producing gallons of water every day. I forget the exact figure - well, it's not exact anyway and varies from one person to another - but you transpire about a gallon per person per day just by breathing. Your lungs are wet and you breathe in and out from twelve to twenty time a minute. Breathe on a mirror or on your window for a minute if you doubt it. Add to that your steam from showers and cooking to get something like eight quarts per day and multiply that by the number of people living in the house. If yours is a yuppie lifestyle, where you eat out and are gone a lot, it's surely less but you get my drift. If you have any green wood and/or paint drying still...
If there is no way for the house to dump that moisture, it will sick around and cause worse trouble than wet windows. check into air and heat exchangers to condition your air.
Excellence is its own reward!
"The first rule is to keep an untroubled spirit.
The second is to look things in the face and know them for what they are."
--Marcus Aurelius
In addition to Piffin's remarks, which are the most likely sources, please be aware that the flue gases from a combustion appliance (furnace, water heater, wood stove, gas stove) contain a lot of water vapor and if improperly vented can be a cause of high humidity, and a source of dangerous levels of carbon monoxide.
Have your combution appliances checked by an expert. Use a good CO detector (miunimum quality, IMO, uses a digital readout, better quality is even more sensitive.
There's good info on CO and CO detectors at http://www.aeromedix.com.
Tight houses are more likely to have draft and CO problems.
For a quick check, look at the area under the gas water heater bonnet (the "skirt") on the bottom of the flue an inch or two above the top of the water heater.
Is there a concentration of rust or "dirt" there? If so, you probably have a draft problem. (Lack of rust after only two years doesn't mean you don't have a problem!)
Turn the heat level control up to make the burner come on, and put your hand at the opening at the bottom of the skirt. Feel any hot flue gases on your hand? If yes (for more than a few initial seconds) you have a problem.
Leave the water heater burning, and turn on the bath exhaust fans and recheck for flue gas spillage at the bonnet.
Open the garage door (if attached - the front door if not) and recheck.
Do your furnace/boiler flue and water heater flue "Y" or "T" together?
Turn off the water heater and let it cool for 1/2 hour. Turn up the thermostat to get the furnace/boier going. Let it burn for 2 minutes, and refire the water heater and check for flue gas spillage at the bonnet.
Look at your flue pipes. Any drip marks or rust? Problem.
Is the top of the flue at leat 1 foot above anything within 10 feet? If not, possible draft problem.
Even if all of the above are "ok" you should have your furnace/boiler serviced and thge flues checked (and do that yearly.)
Most people know high levels of CO can kill, many don't know that regular exposure to low levels can cause serious long term health problems. Just becasue you aren't dead doesn't mean you don't have a CO problem.
________________________________________________
"I may have said the same thing before... But my explanation, I am sure, will always be different." Oscar Wilde
But not in the case of CO!
You mentioned that your house is a "modified post and beam". I wonder if part of the moisture is from the lumber drying out?
I used to work in a fire hydrant factory. You couldn't park anywhere near the place.
Thanks for your comments. I am leaning toward the tight house theory combined with the drying of the beams. They were green when I put them up but I dont know how long it takes for them to really dry.
My boiler is a direct vent unit and the hot water heater is an indirect heating unit. The ceilings in the basement are covered with double foil bubble wrap. The radiant heat is fantastic. I took a digital thermometer probe and applied it to the floor all over the house and amazingly the temp did not vary more than a few 10th's of a degree anywhere. It is a rather pricy item but well worth the cost. The house is about 3000 sq ft and I have 9 to 10 grand tied up in it, including the hw heater. It is very labor intensive especially the electric but my local supply house completly laid it out for me. It took me 5 months with 3200 ft of pex tubing.
In a couple of weeks I am going to install a Vermont Castings wood stove and hopefully this will eliminate the moisture. Thanks again.
Mike
In a couple of weeks I am going to install a Vermont Castings wood stove and hopefully this will eliminate the moisture.
Furnaces and stoves etc don't dry out a house, at least directly. They take dry cold air that infiltrates the house (to replace the air going up the chimney) and warm it up to make it warm dry air..
Be sure to follow the manufacturers instructions for venting and combustion and makeup air.________________________________________________
"I may have said the same thing before... But my explanation, I am sure, will always be different." Oscar Wilde
Mike,
The first winter in a new house is the first real chance for it to dry out. Concrete takes something like 6 months to fully cure and releases mositure in the process. Framing lumber may come kiln dried but by the time the construction id complete it has been exposed to enough moisture in the environment during constrution that it holds a fair amount of moisture as well. Almost all of the materials in building homes is hydroscopic, that is the moisture content is affected by the moisture content of the surroundings.
You did not describe the basement/foundation construction or where in the country you are located. You also mentioned nothing about forced air or exhausts. Well sealed or not, you house will leak. If there are no problem sources of moisture, such as an unexhausted kitchen or bathroom, poorly vented fuel burning appliances or the like, unsealed concrete foundation, basement floor or crawlspace, you are probably just seeing the materials realeasing moisture into the home.
" Framing lumber may come kiln dried but by the time the construction id complete it has been exposed to enough moisture in the environment during constrution that it holds a fair amount of moisture as well."
I don't have any numbers, but I don't think that the framing lumber will pickup any more moisture from being exposed over the long haul. It might have some extra surface moisture from a rain shower, but it will quickly dry out from that.
But kiln dried CONSTRUCTION lumber is a max of 19%. That is low enough to get rid of all of the free water and low enought to prevent rot and fungus from growing.
But the final equalibram moisture of lumber inside a home is 6-8%. That is what furniture lumber is dried to.