Basement humidity

[jasonv93]

Anyone in Calgary ever have issues with basement humidity? What should the levels be in my basement anyways?

When finished it drywaller says its pretty humid. Been running dehumidifier when needed.

Any suggestions? Main floor is 50% basement sits around 60%

[mr2mike]

Is there a fan in any downstairs bathrooms with a shower or bath? You need to make sure that moist air gets cleared out after a shower.

Also, is water outside being drained properly away from the foundation? Could water be seeping your foundation making the walls damp -->moldy---> not healthy?

[jasonv93]

I don't have a bathroom down there and the water is draining away properly....may be coming up through the floor a bit as it was damp down there in past(in the gravel under cement pad)

i finished it last year and checked all walls and had a basement guy out. He tried to sell me some very expensive floor tiles and a sump pump. all the builder would have had to do was put a vapour barrier under the cement pad before pouring it. Too bad this isn't code and i was never told about the option

[gyromonkey]

Ideally in Calgary you want to have you humidity between 35-45% in a new home, typically here we get between 28% and 35%. What kind of foundation wrap do you have on your house? or is it just tar? Was your basement floor painted before Possession? or did you paint it after?

[jasonv93]

We painted our floor after possession with a concrete paint from home depot.

The foundation is sealed with that watch dog sealer that is a rubber type seal.

I noticed our neighbour's house house has similar humidity levels (within a few percent lower than ours)

[gyromonkey]

How long after possession did you paint the floor? 95% of builders pour the basement floor before Interior finishing (I.E. Casing doors and kitchen install) do you know how long that was done before you painted the floor? A concrete floor will dump 200 gallons of water into the air during the process of it curing, that can take up to six months. I have seen people paint their floors right after possession then have issues with water pooling under the poly separating the frost-wall and the floor, I'm in no way saying that this is the case but by painting the floor you may have trapped in the moisture under the floor, and it will take longer to evaporate.
I have complete 90% of my master builders courses through PHBA. Including Moisture control and Alberta soils.

What part of the City is you house located (area?) Are you in a lower part of the neighborhood? What year did you take possession? Did you get a City of Calgary Grade Cert? Is it a Walk out? Does it have a walk up?

Sorry for all the question, the more we know the better, You can Rent a Dehumidifier from Home depot That might be worth a try.....

[Waldi]

Humidity is also function of temperature, if you basement is cooler it may also be more humid, other factors that will have impact, not as many windows, sealed walls, floors etc., will have impact as well.

[jasonv93]

We painted the floor within the first 6 months of moving in. I then finished the basement shortly after that.

Yes we do have a grade certificate, not a walkout, took possession Jan 2010, in Auburn bay, and I all ready have been running a dehumidifier since our dry waller brought to our attention the humidity.

I had the builder in and they said due to the cooler temps in the basement u will get more humidity and since we had an empty lot next to us at the time, the water from it would be affecting our basement. The houses are all done around us and still a bit humid.

I should say that we have one of those yards that grade high in the back towards the house but then by the house it grades away from the foundation.

I did have some spots with water pooling back before I finished the basement. It actually led to some of my items having mold grow on them.

I just don't want there to be mold forming under the carpet I have laid on the concrete floor.

There is just one window in the basement and I never have it open.

[gyromonkey]

It's very true the cooler the temperature the more humidity

I know when I deal with new home owners at work I always advise them to hold of basement development for a year, Ideally.

That's a good thing you got a grade Cert, and a dehumidifier going

I'm not really sure why water on empty lots next door would really make a difference on the humidity in your house, you should have a sealed building envelope, More then likely just some BS the service guy fed you, that is going with what you said about never opening the basement window down there.

Depending how you installed your carpet you may want to pull it back in a couple spots and see if their is any hint of mildew or mold. Hopefully you used Smooth edge and Underlay and did not glue the carpet to the floor, If their is a mold you will have to remove the underlay replace it and possibly the carpet, Don't reintall it until the issue is fixed or you will be doing it again.

To clean the floor you can use KilZ you can get it at home depot.