Mold And Moisture Problem...

Max10

I have a customer that has a rental house...Its a ranch house with a unfinished basement, concrete floor 28 X 40...cinder block basement with an oil furnace (blown hot air) The tenant been complaining about mold growing on the bottom of the walls right above the baseboard in almost every room... I went over to check it out and he had it sided about 6 yrs ago...They put up ventilated soffit but they didn't take down the plywood underneth....they only cut 6" X 6" hole in it every 8ft...The owner went up and put a ridge vent on the roof 3 yrs ago...

I took down the soffit and completely remove the plywood and put foam baffles in every rafter opening so the insulation wouldn't block air flow. The attic has blown insulation in it..It was built back in the 60's so the insulation is the stuff that looks like bird food..he only has about 2 inches total throughout the attic...I closed the side gable vents up with siding. The tenant keeps a dehumidifier going in the basement all the time...Cant really figure out why this house has alot of moisture...Hopefully I corrected the problem with opening up the attic...

Anybody have any ideas what could be causing the mold..

mdshunk

What's the exterior grade look like? How close is grade to the bottom plate? Does it slope away from the house? Is there masses of shrubbery and/or mulch beds against the siding?

What condition are the gutters and downspouts in? Are the downspouts directed away from the house well?

Does any sump pump pump sufficiently far away/downhill from the home?

Does any paved driveway or carport slab slope away from the home? Does any paved patio or walkway slope away from the home?

747

Go to dollar store and buy tilex mold and mildew spray. Its so strong you just spray walkaway and it just disappears. That stuff is clear your sinus strong.

Max10

I think the house might not be insulated enough. The person that put the siding on went right over the lap board with no insulation...The landlord said he had no mold problems until he had the siding put on..I'm lost on this one...

Max10

I told the tenant to kill the mold with bleach and get a primer sealer called B.I.N made by Zinsser Co. its a white pigmented shellac...its the only stuff that ever worked for me on covering stains and keeping them from coming though...Home Depot sells it...

theworx

I love BIN especially using it in a small room. You've taken care of the other issues but how are the windows, could moisture be coming in there and running down the walls (if they are older windows they might allow moisture in). Water will run everywhere and if it sits and soaks into the drywall it will for sure show water damage and mold after a while. Something to look into....

Max10

The living room and the kitchen have the old Anderson windows single pane with storms...He replaced the other windows with vinyl replacement windows. not sure the brand or if they have low e or argon in them...There was alot of moisture on all the windows in the house the day I was there...the windows in the side and entry doors was terrible...The mold is forming all over the place just not under the windows...

K2

I'd be cutting into every wall untill I found where the problem is. Something is not right and it could cause serious health issues. The people should move out in my opinion.

Max10

Could it be the insulation that was used or lack of it in the walls? There is only 2 inches off that old blown in insulation in the attic...not sure if the walls are insulated.

K2

No. there is a problem.

Max10

I am keeping my fingers crossed that it was the soffit...now the eves are completly open...

You said you would be ripping the walls apart..what would you be looking for?

K2

I'd look to see how bad it is on the inside. If you see it on the finished walls chances are it is really really bad on the inside of the walls. Then I would look for the source of moisture. Something has to be obvious for there to be that much mold.... But I could be wrong. I've torn apart 2 moldy houses.

troubleseeker

You already answered your question as to why the house has mold when you said there is lots of moisture.Mold spores are everywhere naturally, and when the conditions are right, mainly dampness and proper temp, they will bloom.You can kill the "bloom" with a solution of household bleach and water, but the spores will still be there; they have a life only about a day less than uranium. You have to eliminate the growing conditions. I would look to the furnace. Could the exhaust flue be leaking excess moisture into the basement, where the warm air leaks into the bottom of the walls and condenses? Or is there a sufficient supply of fresh air for combustion. If not, I would suspect that the furnace is drawing cobustion air through the leaky plate/foundation joint, once again causing moisture problems ate the bottom of the walls.

maj

Most likely the old oil-fired furnace. Since it was resided, it is probably a little tighter than it used to be, causing a lack of air infiltration. A new high-efficient furnace would help. Definitely sounds like an HRV or at minimum, an air to air exchanger is needed. The house is beeing starved of fresh air, causing excess moist, stale air to condense.

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A+Carpenter

I can tell right off the bat that this is a seal plate problem from word one.

Best alternative is to snap a line all the way around the house and remove the first sheet of drywall and fix the mold problem. The seal the plate and your jobs done. We run into this problem all the time and this is the most cost efective solution for a mold problem at the stage you described.

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Zack

There are alot of problems you deal when the house is older. Is it on slab or pier and beam. Many problems are because the moisture under the house. If there is not vents letting it dry then you get mold. There are many,many issues that can help mold grow. Go to www.iaqm.com There is a section for education and it will help you better understand what you are dealing with. Good luck.

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radiant barrier

Need to prevent the transmission of moisture. Mositure barriers are the best solution. see us for more info as many products can be applied to basement foundation walls and under the stringers.
Barrett Enterprises Inc.

john haddad

Sounds to me as though the house is a leaky and therefore all of the moisture in the basement is traveling through the home as vapor. a blower door test would measure the air infiltration.

My nephew's attic sheathing rotted out due to moisture problems coming from the basement.

Insulating this will not stop the problem. The house will need to diagnosed of the problem first. Air sealing the band joists and any penetration (electrical and plumbing) in the basement ceiling is half the job.

Next is sealing the attic - top plates and all penetrations.

Now the house will have little to no air movement and it will be time to insulate the attic to an appropiate level. A minimum R value of 38 would be recomended.

If you insulate first, you are not stopping the moisture problem and the new insulation's R-value will be degraded from the moisture.

Adding the insulation could have tightened up the exterior, but the air movement through the house has just changed paths.

What is the cost to heat this unit.

sheeter

In standard construction, the ceiling joist sit on top of a double plated wall. With the exterior sheathing nailed to the top plate as well as the interior sheetrock, how much air movement would you have between the walls and the attic space? I simply don't understand how a ridge vent and soffit vents will cure a moisture problem at the base of the walls. I would want to take a look behind the vinyl siding to see whether the installer did something to prevent the house from breathing. I work on a house once that the builder had put plastic on the interior side of the studs before hanging the sheetrock. That plastic became the condensate screen because the house couldn't breath, and rotted out the base of the walls. It became a major structural remodel.

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Sheeter
"It's hard to be humble when your good"

denick

Max 10

From the type of work we do we have found a hidden source of moisture can be in the concrete block walls of the basement. Built correctly, inside the walls is an open maze of space that once moisture is in side it it can stay forever. Just vapor moving into that space and condensing can supply enough moisture to keep things very wet. This wetness might not show up on the interior block in a way that you would focus on it. Once the moisture is inside the wall cavity the warming of the day on the outside top blocks causes the moisture to rise and condense above. When things cool outside the moisture falls to the bottom and starts all over again the next day.

Think like the inside of a terrarium.

Many times older block foundations are not capped by solid block and the top blocks are not filled with cement and the wood construction is the place the moisture condenses.

The other thing that we find in that type of situation is no air flow around the foundation. A lot of plantings and shrubs and close in overhanging trees that do not allow air to circulate and dry things out.

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Nick

"Every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving" Albert Einstein