N/F Humidity and Condensation inside the house

[atvaholic]

Hi, wondering if anyone has the same problem I have been having.

 

I have a house about 5 years old that is full of humidity. The home is regularly between 55 - 60%. I have done quite a bit of research. As a result of the research, we have been careful to use the fans when showering/cooking, etc. We only have 3 small plants in the house. We have been concious of this all winter, but the humidity stays the same 55-60%.

 

The problems that arise from this are that water is constantly on the windows creating mould, and dripping onto the sills starting to rot them out. When its really bad the water actually drips onto the floor.

 

I called the homebuilder, and they have come to inspect several times, but cant see any problem anywhere. They attribute it to the newer houses being too sealed to specs. I also called the window manufacturer - again, apparantly no issues. The homebuilder keeps suggesting we remove all the plants, leave all the blinds FULLY up on the windows, leave the shower fans on for several hours, and also run the furnace fan a few hours each day to circulate the air. None of this has helped. Leaving the drapes open 24/7 does help the accumulation of water on the windows, but this is not a viable option. We leave them open from about 7am - 6pm and it helps, though it does not eliminate the condensation.

 

Another problem with this level of humidity is the house feels cold and clammy - even though my thermometer is set at 22.

 

Just wondering if anyone else has dealt with this and if they managed to fix it..

 

thanks!

[mercman]

Most newer homes are, as you said, better insulated and more hermetically sealed, that is why they have or should have air exchangers. Does yours have one ? If not, i suggest you get 1 installed.

 

Is this the first winter you have had this problem?

 

 

[JohnF]

Condensation (i.e. excess humidity in house) is always a result of inadequate ventilation regardless of where the moisture is coming from. Obviously if the source is severe pipe leaks or flooding of some kind that's going to show up quickly.

 

As someone mentioned in today's new homes an air exchanger is almost a necessity. I wouldn't build a house without one. Barring spending the bux for installing one now you'll have to figure out how to improve the ventilation by keeping windows open a crack when possible and by running exhaust fans regularly. There's always a switch just outside the bathroom that controls the bathroom fan. That's what it's for.

 

Some other things my new home customers have learned.

1. A lot of live house plants make a lot of humidity

2. Is the house closed up tight for long periods of time, like when everyone's at school and work, or if there are elderly folks living there who don't ever open the doors or windows. Even normal door opening through the day can be a big factor.

3. A hot tub in the basement (or elsewhere) that has water in it all the time.

4. New concrete lets off a huge amount of humidity for a long time requiring extra ventilation for the first few years. Think of how sloppy cement is when it's poured and then think about how much goes into a house (foundation, floors, grout etc). Where does all that water go when the concrete cures?

5. Aquariums

6. A lot of showers and laundry for a big family or a bunch of clean freaks. My two boys would have 2 or 3 showers a day when they were in hign school. We gave up on trying to keep real tile in the bathroom tub surrounds.

 

Give some serious thought to how you control your home's ventilation. It's tempting to try to conserve that nice (expensively) warmed air but resist it. Not only does it retain moisture but it also retains nasty things in the air you breathe. If you can possibly afford it get an air exchanger system installed. That should address all your problems and it will also contribute a lot to the comfort level of living in the home and later, when you decide to sell, the air exchanger will be an attractive feature to buyers.

 

JF

Edited February 28, 2011 by JohnF

[Rod Caster]

55-60% humidity will definitly create mold in your place. It should be 45-50% . A dehumidifier might help this, but adds to your energy costs. You may want to consider better venting and air movement in your place. Sounds like the builders focused on insulation rather than air movement. As Merc said, some newer houses are sealed too well and invite humidity retention and mold growth.

 

Consider going through insurance and calling it water damage. Record everything you do including dates, photographs, ...keep a good log.

If it goes through insurance, they'll send in professionals that know how to solve your problem. The builder might be on the hook for the claim.

 

If it wasn't so darn expensive, I'd suggest calling mold experts in right away, they would help you properly ventilate the place.

Edited February 28, 2011 by Rod Caster

[lookinforwalleye]

I believe that an air exchanger is part of the building code now, and yes the main reason condensation is so bad is because the building envelope is so tight.

I recall once a few years ago in another home I owned we had a party and there was perhaps 40 people in the house, the condensation was so bad we had puddles of water on the floor underneath all the windows and when someone would open the front door a cloud of vapour would rush out of the house it was interesting to see that cloud rush out of the house.

 

The house I am in now does not have that problem because it was built 30 years ago before they started wraping things up tight which means the house is breathing, new houses don`t breathe.

 

I would look into a air exchanger because no matter what you do you will never get rid of the humidity build up unless you exchange the air!

[atvaholic]

Thanks to all who responded. Here is my response to some of your questions.

 

1. We have had this problem(condensation and mould) since we moved in. Of course we moved in the spring and did not notice the issue until winter.

2. I do have an aquarium now, but never had one the first two years we had this issue.

3. I am home during the day (I work from home) so I do make a point of cracking a window and running the fans.

4. The only thing different about my home then many others is I have a walk out in the back - so there is a large area of poured concrete (side split I beleive)

5. I ran two dehumidiers at one point. They did slightly lower the humidity in the area around them

 

I have been in contact with several people about an HRV. Big $$$ for one.

 

I would have no issue with buying an HRV - except that both my sister, parents and, brother in law an in-laws have new homes - I am the only one with this issue. My sister lives right behind me (house built by the same builder) And has two teenage children who like to take long showers...yet her humidity is at 45%, rarely it does go up to 50%. Leads me to beleive somethign else is at play here.

[Rod Caster]

If it's mostly just around the windows then I'd say it's a condensation leak, but that does not explain the high humidity.

 

I have a condensation leak in my condo and even at 40% humidity I see condensation on my ceiling. It's all associated to bad insulation and cold air coming in contact with my walls/ceiling.

[vance]

You didn't mention it,but does your furnace have a humidifier on,if so it may be the cause.

 

vance

[atvaholic]

You didn't mention it,but does your furnace have a humidifier on,if so it may be the cause.

 

vance

Hi Vance -

 

No, there is no humidifier on the furnace at all.

[mikemcmillan]

Long shot but you never know, is the furnace fan working properly, dirty filter, air movement is a key.

[mercman]

Here is a really good article that may help you discover the source, or control the problem.

http://www.fcs.uga.edu/pubs/current/B924.html

 

 

Paul

[muskymike]

John made some good points. Have you checked your return air ducts? New houses are not sealed as tight as everyone might think. Some are, yes, but most are not. And when you hear of builders building such a tight house, in theory they are, but if you ever have a chance to go see a new home being built look at some of these area's. Houses are not nearly as tight because of:

 

Header wrap not sealed around corners

Header wrap ripped/torn around anchor bolts

Top of foundation wall poured poorly, sill gasket not providing air penetration reduction(only serving as moister barrier between concrete and wood)some foundation walls are out 1" over 30 feet.

Inside chases/bulkheads, vapour barrier not sealed around perimeter with strapping, same situation with walkout or lookout basements

Garage ceilings (entire ceiling), batt, spray foam, vb, cold zones (beams exposed to cold air)

 

These are just some of the continuously problematic areas with all builders. In order for your house to be considered tight, the allowable infiltration is about just under the size of a basketball. This means every air penetration your house is allowed, if you added them all together in area, they all add up to under the size of a basketball. And thats a tight house. Not all builders are achieving this.

 

Your humidity levels are most likely due to lack of air movement as a few have said before, but look a little closer at your furnace and your returns. Most builders are not going to help you, and the warranty guys they bring in usually dont know much about this stuff. As you have done already, start checking off stuff. Its not your doors/windows, the fans are good to run, but not for extended periods of time, you dont have a humidfier, not many live plants. Now focus on the areas that provide moisture, your furnace or an abundance of water. Your foundation doesnt spit as much vapor into your house as you may think. It does, but not enough to have you worry 5 years in. Check your vapor barrier. This could be one of your main issues. As well as Kitchen Hood Fan or Dryer duct work (least probable)

 

As someone said before, HRV's/Air exchangers are good investments, but new homes do not require them. Certain scenarios in the 2012 code have HRV's required under the new insulation guidelines. But are not currently required.

 

Sorry I went off on a few tangents here, but there are many things that will be looked at and probably only 1 or 2 that need to be if you really narrow it down. Hopefully this provides some insight, I know I was all over the place. PM me if you want, I work for one of those "builders", one of the larger ones.

Edited March 1, 2011 by MuskyMike

[DRIFTER_016]

Send a letter to Mike Holmes, he lives for this stuff!!!

[lookinforwalleye]

John made some good points. Have you checked your return air ducts? New houses are not sealed as tight as everyone might think. Some are, yes, but most are not. And when you hear of builders building such a tight house, in theory they are, but if you ever have a chance to go see a new home being built look at some of these area's. Houses are not nearly as tight because of:

 

Header wrap not sealed around corners

Header wrap ripped/torn around anchor bolts

Top of foundation wall poured poorly, sill gasket not providing air penetration reduction(only serving as moister barrier between concrete and wood)some foundation walls are out 1" over 30 feet.

Inside chases/bulkheads, vapour barrier not sealed around perimeter with strapping, same situation with walkout or lookout basements

Garage ceilings (entire ceiling), batt, spray foam, vb, cold zones (beams exposed to cold air)

 

These are just some of the continuously problematic areas with all builders. In order for your house to be considered tight, the allowable infiltration is about just under the size of a basketball. This means every air penetration your house is allowed, if you added them all together in area, they all add up to under the size of a basketball. And thats a tight house. Not all builders are achieving this.

 

Your humidity levels are most likely due to lack of air movement as a few have said before, but look a little closer at your furnace and your returns. Most builders are not going to help you, and the warranty guys they bring in usually dont know much about this stuff. As you have done already, start checking off stuff. Its not your doors/windows, the fans are good to run, but not for extended periods of time, you dont have a humidfier, not many live plants. Now focus on the areas that provide moisture, your furnace or an abundance of water. Your foundation doesnt spit as much vapor into your house as you may think. It does, but not enough to have you worry 5 years in. Check your vapor barrier. This could be one of your main issues. As well as Kitchen Hood Fan or Dryer duct work (least probable)

 

As someone said before, HRV's/Air exchangers are good investments, but new homes do not require them. Certain scenarios in the 2012 code have HRV's required under the new insulation guidelines. But are not currently required.

 

Sorry I went off on a few tangents here, but there are many things that will be looked at and probably only 1 or 2 that need to be if you really narrow it down. Hopefully this provides some insight, I know I was all over the place. PM me if you want, I work for one of those "builders", one of the larger ones.

 

 

HRV`s are required under the national building code unfortunately Ontario has opted out of this requirement, I would suggest that a quality builder that actually cares about the product they build will include it or at the very least offer it as a option.

[atvaholic]

HRV`s are required under the national building code unfortunately Ontario has opted out of this requirement, I would suggest that a quality builder that actually cares about the product they build will include it or at the very least offer it as a option.

 

Hi Again - I tried to keep the issue as short as possible and left out one thing. I had someone inspect the furnace/vents a few weeks ago. 2 of the return air vents were not working properly. The home builder has fixed the problem - I thought my worries were over, but has not changed the humidity at all. I have also had a dehumidifier running for several days, it just seems like its not enough. I have this feeling I will need to shell out the cash for an HRV - But still don't fully understand why.

 

Thanks for the responses again.

[Fish4Eyes]

Do you have return air vents in every room? Do you change your furnace filter every 2-3 months?

 

I have a musty smelling basement especially in the spring/summer, but yet do not see signs of mold or water anywhere. Although, it is the only level in the house that does not have a return air duct and I'm suspecting it smells musty because of lack of air movement. Any thoughts?

[muskymike]

HRV`s are required under the national building code unfortunately Ontario has opted out of this requirement, I would suggest that a quality builder that actually cares about the product they build will include it or at the very least offer it as a option.

 

True, but pointless. We are in Ontario, therefore they are not required. The NBC holds a lot of requirements to which "certain" provences exclude.

 

As for "quality builder", I couldnt agree more, but the reality is, the dollars speak volumes compared to what should actually be done. The cost to the builder is rediculously high, even for large volume builders, so I could only imagine what it is to a smaller builder. Every builder usually offers this but it usually exceeds 3-4k selling due to mark-ups and such.

 

Sorry, had to chime in, not arguing, just wanted to clear that up from my end.

 

Now lets get back on track and see if we can solve this issue.

[Twocoda]

have your builder come in and pop off the trim and casing around the wettest window (or do it yourself)...the condensation level to cause mold on a window sill is most likely due to improper insulation and sealing around your window....

 

if you decide to investigate yourself simply pop off the trim around the window casing and inspect to ensure there is insulation there...if the drywall carries over too far to visually see the insulation ...take a screw driver and tuck it in the void to "feel" the insulation...(from experience i would take the top trim peice off the window first as it is usually the one that gets overlooked)and the most difficult as a ladder or stool is usually required to do the job.

 

Belive it or not ...NOT everyone wants HRV in their house...it depends on the style of house....if you have shed dormers with case windows ...then yes its a must (and there should be vents in the dormers)... there are alot of people that like the exhaust of thier over range fans to be vented outside rather then charcoal filters...

 

As stated earlier ...HRV is relevent to the purchase price of a house....so tack on 3-4 k for sale price

 

Good Luck ...hope it helps..

 

 

edit to add....you may also want to ensure your condensate is working on your furnace and not plugged

Edited March 1, 2011 by Twocoda

[Governator]

I have a similar issue but only upstairs and mostly contained in 1 room, the one above the garage facing east (New house, moved here in 2007). Frustrating for sure.

[Ron]

Hi, wondering if anyone has the same problem I have been having.

 

I have a house about 5 years old that is full of humidity. The home is regularly between 55 - 60%. I have done quite a bit of research. As a result of the research, we have been careful to use the fans when showering/cooking, etc. We only have 3 small plants in the house. We have been concious of this all winter, but the humidity stays the same 55-60%.

 

............

 

Just wondering if anyone else has dealt with this and if they managed to fix it..

 

thanks!

 

I have checked for this problem in a few places. On 3 occasions, I found the dryer vent not functioning properly. In one instance, the dryer vent was attached but the duct was full of lint not allowing the moisture out. In another situation, the dryer vent hose had a tear in it. The third occasion, the additional auxiliary fan was not operating thus didn't allow proper air flow to the exterior of building. I have also had bathroom exhaust fans not work properly as well.

 

Take a tissue, turn the hood range fan on, put the tissue up against the filter. There should be more than enough vacuum to hold the tissue in place. Try this with your bath room exhaust fans as well.

 

How long does it take to dry your clothes from the dryer? Do you think it takes longer than 25 minutes to dry a load of jeans? If so, check for moisture coming out of the dryer vent, on a cold day preferably, to see how much moisture is exiting. There should also be a substantial amount of air blowing out as well. Ask to check your neighbour's dryer vent for comparison.

 

Hope this helps.

 

Cheers, Ron...

Edited March 1, 2011 by Ron

[danc]

Take Rons advice. He's an expert on too much humidity in a dwelling. Last time I saw him, his dryer vent in his tent was plugged. This was the result.

 

[danbouck]

Isn't 55% - 60% the normal percentage for inside a house

[Tinman]

I would highly recomend an Hrv in any new home, Code or not. The exchange of air will remove the humidity. I have a friend of mine whose windows were constantly running(older home) Installled an hrv for them and now the moisture level has droped considerably! A house should be somewhere between 35 to 45 %, A little more if you have hardwood. Another thing to check is the venting for your furnace if it is a high efficeincey. I service call i went on, the alternate plug for the furnace was not in correctly, allowing the products of combustion back into the house, which too contains moisture. If you have any more questions drop me a line and i'll see if i can help.

[danc]

The proper humidity level inside of a house varies depending on what the outdoor temperature is. Here's a good guideline.

 

 

 

Outside Temperature Indoor Relative Humidity

Above 50 °F Not over 50%

Above 20 °F Not over 40%

Between 10º & 20ºF Not over 35%

Between 0º & 10ºF Not over 30%

Between -10º & 0ºF Not over 25%

Between -20º & --10ºF Not over 20%

-20ºF or below Not over 15%

 

 

I'm sure sure about todays humidifiers or hrv's, but when I did residential work many years back, there was a chart right on the dehumidistat itself similar to the above.

[nofish4me]

The least expensive and least complicated that I could find was a unit made in Quebec.

The only drawback, the furnace fan needs to circulete for this to work.

 

http://www.venmar.ca/AirExchangeConceptPage.aspx