I'm new here and just had a few general questions if somebody in the know could reply.

What would be the average humidity level in the summer of an unfinished bsmt that is properly waterproofed in New York? Mine is about 75%. I'm not saying whether mine is properly done.

Does the application of products such as Drylock or other brands have any benefit if the bsmt is already properly waterproofed? I have not done this yet but am considering.

And is it necessary to waterproof a foundation such as a garage that is above grade? Mine wasn't and one side has a sloping foundation wall that reaches about 9 ' below the garage floor. There is no bsmt under the garage though.

Thanks

Chris

The humidity level of a trouble-free basement should be approximately the outdoor ambient humidity. There is no one set average.

I have no direct experience with Drylock, but a few voices in thie forum regard it as a band-aid at best, and if there is a serious moisture problem, it won't work forever.

In a case such as you describe, it isn't necessary to dampproof the foundation. If it is block, it should be parged with cement plaster, though.

Dampproofing isn't waterproofing. Most basements are only dampproofed, not waterproofed. Depending on the age of the house and other conditions, the dampproofing may have been compromised.

Thank Richard,

That's great info. My basement was poured so that's one less thing to worry about.

I have just recently been having a problem with my walkout bsmt though. There are a few cracks in the foundation, bottom corners of 2 windows extending diagonally down to floor, which have just recently started to leak at around the floor joint. I do believe these cracks extend thru the foundation wall as I can see some cracking on the stucco outside.

Also, my basement was rubrwalled three years ago, when built, but the bsmt walk out part, had no waterproofing done at all. I was thinking about having it dug out and applying some of the remedies mentioned here on the board.

My questions are :

Does it matter what kind of hydraulic cement or what brand, or are they pretty much all the same?

Will anything that says elastomeric be sufficient as a waterproofer?

Will any 6 mil plastic will do?

Thank you

Chris

Your humidity level in your basement is a little high. But if its a issue would depend on how its finished. Anytime humidity is that high mold can develop. With that said if the basement if finished in any way. Wall board and furniture will develop mold.
Typically levels below 50% are desired if possible to achieve.

As far as Dryloc or any other brands of sealant on walls. Waste of money. They will do little to lower humidity and a lot to hide and mask water entry issues within a basement. If the basement was properly water proofed from the outside, no need to paint inside. If for any reason the walls were painted prior to the Dryloc being applied it will not work anyway as there will be no warranty. This type of wall sealant only works on virgin cement block walls.

No reason like Richard said to Dryloc the garage walls.

Are humidity levels around 50% possible in the summer without running a dehumidifier?

Yes, if it's 50% or lower outside, and no if it's higher. Your basement will rise and fall in himidity, just as your house does. The only way to control humidity at a fixed level is to condition the space. But, isn't the issue a question of where the moisture is coming from? Basements do not create humidity. There has to be a source of moisture.

Your cracks at the corners of the windows are classic places for a wall to crack. In commercial work and in good residential work, a series of short reinforcing bars are placed at 45 degrees at such corners to control the cracking. Almost no residential foundation contractors do that,, hence the cracks that you see, which occur because a corner like that is a place where stresses concentrate in the concrete. All concrete cracks. The trick is to keep the cracks at the microscopic level, so they cause no harm.

Yes, the cracks should be repaired and the walls waterproofed outside, but I will leave the recommendation of specific products to those who have hands-on experience. I just draw the pictures. =)

Humidity was 35% outdoors today in the morning and rose to 50% during the day. Its been rain free for days. The humidity in my basement was at 66% in the morning before I opened the windows and rose to 72% after I opened the windows for a few hours. I tend to think that the humidity will always be higher in the bsmt due to the hot summer air hitting the colder bsmt walls. I have never had humidity lower that 50% even in the winter. I think it's impossible to have a bsmt with low humidity around 50% in the summer without a dehumidifier. This is NY. Just my opinion.

By the way, what is the humidity level needed for mold to grow.

Notice that the humidity level in the basement rose less than the outside humidity, which would tend to refute your theory about the humidity coming from the air and condensing on the walls. If it did that, you would see the condensation. Yes, there will be a lag between the outside and the basement, but if the outside humidity stayed the same for a few days, the basement level would stabilize at about the same level.

Basements do not create moisture. If you have it in excess of the outside humidity level, then the moisture is coming from somewhere, and it should not be doing so. It could be penetrating the walls, or coming up through the floor, but if it's there., it came from somewhere.

Is it necessary to waterproof the joint where the footings meet the foundation wall if the slab is above grade on the walkout bsmt part of the house?

Maybe that's where I might be getting some extra humidity. The house was rubberwalled on three sides except for the walkout bsmt side. There is no waterproofing or damping on this side.

Just throwing that out as a possibility.

Mold will develop anytime liquid moisture is present after 24 hours bacteria develops after 48 hours mold begins to grow. The type of mold growth is dependent on several factors. Type of material that it is growing on as well as the location.

Once mold develops humidity levels over 40% is enough to keep the stuff growing. But it’s the liquid that really starts the process. This does not mean that it will not grow in high humidity as it will but takes a while longer.

AS far as your opinion your pretty much right on track. If you have an older basement its doubtful that the walls were properly water proofed or damp proofed if at all.

A dehumidifier is a very expensive method of keeping the basement dry. I would suggest you look into a system such as a Humidex or similar type of dehumidifier. It draws conditioned air from the upper level and draws it out of the basement. While its doing this the dryer air from upstairs picks up the moisture in the air and all is removed. Must less expensive to operate then your typical, a little more to purchase but works better.
Here is a link for the device

http://www.wavehomesolutions.com/index.cfm

If the walls required waterproofing, then the floor remains suspect. There is probably no vapor retarder, or an insufficient one, and probably no gravel under a too-thin floor slab. If the walls were done properly, that should eliminate them as the source of the moisture, and therefore shift the spotlight to the floor.

The house is 3 years old. There was a vapor retarder, plastic, and gravel with, I believe a 4" base. I've read alot of posts here, but not all. Do you think I should still waterproof that walkout wall/footing area? I'd rather not. It's a lotta work. The footing drain is resting on the footing, i believe. I only dug to the filter fabric and stone gravel, about a foot below where the bsmt slab was poured.

I've narrowed down the small puddle I've recently got to the crack near the window down to the slab to the clay soil not draining. The grade as of now has been a few inches above the slab.

My plan was to have the crack filled on the exterior wall and lower the grade a few inches with a more sandy mix of soil so that the grade is a few inches below the slab. Thus eliminating water on that outside wall ever being higher than the bsmt slab.

Yesterday, I dug out the spot were the leaking was emanating from. The footing drains looked good. I ran a water test for 45 minutes and no water came out of the footing drain outlet, which is approximately 45 feet from the house. The house was built on blasted rock and the water just kept on draining into the hole, not filling up. I suspect that because of the blasted rock that the water is just draining down into the blasted rock. It is possible that some of the water is draining thru where the footing meets the foundation wall. I'm not an expert by any means.

I just ran the water test again today and water finally came out of the footing drains 40 feet away from the house.

Well, I thought I'd give an update. I cut out the cracks with a diamond blade grinder and filled them in with hydraulic cement. It was a lot of work for 2 cracks, total of 6 feet. But it looks pretty good and I'm hoping for the best. We'll see how it holds up during the next big rain. Thank you for everybody's help on this board. A lot of great info and helpful posters.

Well we had a big rain after the residual hurricane the other day and not one drop came thru. The hydraulic cement worked great. I wish I found this site before I wasted money on other products such as applying Radonseal, which didn't work at all.

Thank you