When your home was new. Part one.

When your home was new. Part one.

When your home was new, all the systems were in balance. We will call each original system of the home “X”. All changes will be called “Y”. The heating system, windows, insulation, ventilation system, septic system, yard grading etc. all matched in “X”. Now we will see how a perfectly matched home is systematically destroyed by well intentioned homeowners.

This series is intended to help home owners understand how seemingly small changes can affect the entire home.

Part One: House “X” was new and occupied by the original homeowners for 10 years. During the home inspection for the new buyers mold was discovered in the attic.

What changed? This house was built with a ventilated drip edge. This “hicks” style vent was designed to replace standard soffit vents. The caveat with this type of system is that you cannot use gutters with it.

The problem: The overhang on the house was so narrow that when water dripped off the edge of the roof, it splashed on the ground and back up on to the siding causing rot. That could have been avoided if the overhang was larger or the foundation was taller. Not aware of the no gutters with hicks vent rule, the homeowner attempting to solve the problem installed gutters on the house. Water was inevitably trapped in the gutter by debris, leaves, branches, and poor slope etc. As the sun baked the gutters, water evaporated and was drawn into the “vents” over the gutter. These are after all, intake vents which are half of a balanced attic ventilation system. The top half of this system is called the ridge vent.

The result: Excess water vapor in the attic activated floating dormant mold spores. The mold spores attached to the damp attic roof sheathing and started to form colonies. Mold remediation will have to be completed and the ventilation system will have to be changed to allow for the new gutter system.

The solution: Remove the “hicks” vents and install under the gutter soffit vents. Remember to match the intake with the exhaust for a balanced ventilation system. For example: If nine square inches per linear foot is installed at each soffit, then a total of eighteen inches per linear foot will need to be installed at the ridge.

In this scenario, the house was not designed to have gutters. Adding gutters changed “X” to “Y”. Adding the soffit vents and removing the over the gutter “hicks” vents brings the house back to “X”.

Hicks Vents                            Soffit vents

hicks-ventsSoffit venting

 

When your home was new. Part one.

It Looked Good From Out Here:

I was called to investigate a mold problem in an attic. The client had had a home inspection and the recommendation was to have the suspected microbial activity in the attic space further evaluated. I use that same wording on my reports. I asked of there were any pictures from the inspection he could forward to me . Usually the answer is no, the inspector did not take pictures. I take an average of 250 picture when I do an inspection. I digress. This inspector did take pictures and the client sent them to me.

The exterior inspection clearly showed a decent ridge vent and vented soffit panels. The interior showed soffit vent chutes. The inspector did the right thing in requesting a further evaluation. The inspector cannot disturb insulation while performing the home inspection. He couldn’t see that air sealing was not completed under the insulation. That’s not his job, it’s mine. Because there was no floor in the attic, the inspector could not enter to perform a complete inspection. Again, not his job, it’s mine. I brought some temporary flooring with me and crawled into the attic space. With the lights off I should have been able to see daylight at the soffit area. I thought this was another case of the siding contractor installing vents over solid wood soffits.

What I found was unusual. The siding contractor did cut the opening for the soffit. The soffit panels were covered with debris restricting air flow into the attic. We simply removed the soffit panels, vacuumed the panels and openings and re-installed the panels.

While measuring the attic for mold remediation, I noticed another problem. The insulation contractor used blown in cellulose insulation which is fine. However, he also managed to clog the ridge vent with insulation restricting exhaust at the ridge. We simply vacuumed that too. Proper ventilation was achieved with a vacuum cleaner. Air sealing was achieved with four cans of spray foam insulation. We remediated the attic , the deal went through and everyone was happy.

Looks good out here. See debris in soffit vents 1

Perforated soffit panels

Debris on soffit vents

Clogged soffit panels

When your home was new. Part one.

The Improperly Installed Ridge Venting:

A typical call goes something like this. Good morning mold person. I had a home inspection and they found mold in my attic and recommended removing the mold and  improving the attic ventilation system. I had a contractor in to install ridge venting now I need the mold removed.

In my head I am thinking ” mold removal before ventilation” not the other way around. I say it over and over again. The process of mold removal and the application of sealant can clog new ridge vents. I arrived at the house and this is what I found. The contractor drilled a 3/4″ hole through the ridge every 16″, misinterpreting the code of a 3/4″ minimum continuous cut. On top of that he installed a rolled ridge vent that was collapsed and performing no function.

The 3/4″ cut is too small for the amounts of insulation we have in our homes. My recommendation is to double that to 1 1/2″. Also, I have to remove the new ridge vent and caps, properly cut open the ridge and install a new performing ridge vent and caps.

In the image I have here you can see that the ridge cut should be equal to the vented opening of the ridge vent. The blue mesh filter should span side to side.

The other low bid, great deal contractor disappeared after the job and the homeowner had to pay the bill for the new work. I am not completely blaming the contractor. The homeowner is probably equally at fault. I bet there was at least one bid, probably the highest, who told the homeowner exactly what  needed to be done.

Also remember that the general contractor, roofing contractor or home improvement contractor all are not ventilation or mold experts. Hire only qualified and insured (liability and workman’s comp insurance) certified mold remediation and ventilation contractors.

In order: Mold remediation first, ventilation second, air sealing third, insulation last.

Improper ridge venting 1

Improperly cut ridge

Installing a shingle vent II properly

Properly cut ridge and vent

When your home was new. Part one.

Bathroom Fan Venting Into The Soffit

In this home the bathroom fan is exhausting into the soffit area. The exhaust air is being drawn back into the attic accounting for the heavy growth in this area.

The solution was to redirect the exhaust to the gable end with an insulated pipe. If the gable is too far away this could have been vented through the roof.

Bath fan into the soffit

Bath fan into the soffit

When your home was new. Part one.

Its Raining In My Attic

I was called by a customer about a suspected mold problem in his attic. He then told me he thought there may be a roof leak because it sounded like water was dripping. I went out to investigate. Sure enough it was raining in his attic. The roofing nails were collecting water vapor and dripping back down on to the insulation and air handler. The plywood roof sheathing was so wet it looked like a sheet of water was cascading down the surface. The gable end was completely covered with wet slimy black mold.

So I said, “how long has this been going on?”. He said “just this winter”. My next question was, “what conditions have changed since last year?”. He said “we got a new roof a few months ago”.

This is what happened. The roofer installed a rolled ridge vent that completely collapsed upon installation of the ridge caps. Water vapor could not escape the attic. The solution was a new collapse resistant ridge vent. Problem solved. I am sure that at least one roofing contractor wanted to install the correct vent, which cost more, and was outbid and didn’t get the job.

The cost to the client. He not only had to pay for a new ridge vent to be installed but also had to pay for the mold remediation of his attic. Did the first roofing contractor do him wrong on purpose? Probably not.  The roofing contractor is not a ventilation specialist and probably didn’t know any better. In this case the roofing contractor had been using the same ridge vent for years without problems. The vent never worked but the problem of moisture retention did not present itself until the home was made more efficient. When the home was made more efficient the underperforming or improperly installed ridge vent was finally revealed.

With homes getting tighter and tighter as a result of energy conservation, more attention needs to given to indoor air quality and ventilation issues across the board.

Collapsed ridge vent Mold at gable end Wet Plywood