Where does your bath exhaust vent terminate?

It used to be a very common practice to terminate bath exhaust vents at the screened bird-blocking of the roof overhang. Everyone has likely seen bird-blocking, but perhaps you did not know what you were looking at.

Bird-blocks are essential components of the roof/attic ventilation system, and shows between the ends of the roof trusses or rafters at the roof overhang. These vents are where air enters the attic and travels to the roof vents or ridge vents. Also, as their name implies they fill the space between the rafters/trusses to keep the birds out of the attic as well as provide a path for ventilation.  I think the blocking also gets its name from stick-built type roof structures where the rafters had a “bird’s mouth cut in the rafter to sit flat on the wall top plate.  So this blocking was between the bird’s mouths of the rafters.  So they are either a “description” or a “function”—maybe both.

It probably does not hurt the ventilation of the attic too much to “borrow” one of these openings for the termination of an exhaust fan, but it can have some serious unintended consequences.

Let’s assume for example that the vent is indeed going to blow air out the hole of the bird-blocking. If the pipe is butted tightly up against the blocking it will likely work pretty well. However, this warm moist air is being blown into an area that is typically under negative pressure. In other words a lot of this warm moist air is being blown into a space where it is likely going to be sucked right back into the attic.

Another problem we have to consider is that all of this exhausted air has a lot of dust and lint in it. In a relatively short period of time the screen in the bird-blocking is going to plug with lint and then the exhaust fan will stop moving air from the bathroom. This will lead to moisture issues in the bathroom as well as the whole home. The odors we usually appreciate being vented out of the bathroom as quickly as possible will also “linger.”

It is for these reasons that an exhaust cap with a back-draft damper is necessary, and that it be located such that the air being exhausted is not going to be sucked right back into a space we don’t want it. We want to have control over the maintenance of the exhaust system as well as where the air ends up.

As you can see in the following picture the vent screen is completely blocked with lint.

Plugged vent screen

I slid the pipe over 3” just so you could see what happens when the exhaust is installed in this manner. There is a small area at the center of the lint where the screen is visible but this is only so because the pipe scraped off the lint when I slid the pipe over.

Often these vents are buried in insulation and you only get a hint this method has been used by the amount of fungal growth on the soffit at the exterior or on the roof sheathing in the attic.

vent at soffit

When the fan in the bathroom will not hold a piece of tissue paper up against it, this is sometimes the reason why–and it is certainly an indication the fan is not venting properly regardless.

By Charles Buell, Real Estate Inspections in Seattle

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The Cat House & Home Inspection Protocol

 Just walking around a home–looking at it from a distance–I can often tell what might be in store for me on the interior.  Home inspectors will usually take this “macro-view” of the home prior to getting up close and personal with the “micro-view.”  It is a very important part of the home inspection protocol to utilize both of these views of the home–and all the spaces in between.

Crawl spaces

At a recent inspection, as I headed around the back side of the home, I took the following picture.

Cats in the crawl space

I suspected the home probably had a crawl space even though I was told it did not–supposedly built on a slab.

As I saw Kitty-Kitty sticking his head out of the crawl space hatch I knew what this meant–there was indeed a crawl space as I suspected.

Well it could have also meant that this was just the access well and that there was a door behind Kitty-Kitty and he was just hanging out in the access well.

But I knew what this meant.  There was in  fact no cover at all and the crawl space was where Kitty-Kitty lived.  The best I could hope for was that Kitty-Kitty had not turned the crawl space into a latrine and that he would be amenable to my checking out his digs.

As it turned out, not only was he amendable–so was his partner.

cats in the crawl space

Neither one even minded me snapping a few pictures–in fact one never even seemed to wake up.

I was also grateful that their digs was still a crawl space–instead of a litter-box.

Crawl spaces are perfect environments for cats.  They are dark, there is a high likelihood of mobile food, and they can do what cats do.

By Charles Buell, Real Estate Inspections in Seattle

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What is the home buyer’s due diligence period?

There seems to be a general misconception among some home buyers that the hiring of a home inspector is the completion of their due diligence, when in many respects it is just the beginning—or at best just part of the process.

The home inspector will expose the concerns, but often they will not be able to allay justifiable concerns related to those findings.

The problems arise when the buyer assumes that the inspector’s findings are enough. They make their decision to move forward with the purchase based on the inspector’s findings without following through on the various recommendations the inspector has made.

Admittedly, many of these things are probably of little consequence but others could result in the buyer taking possession with later regrets.

For example, getting the sewer scoped. It can be a very big expense to deal with problems with the drain between the house and the city sewer, and yet many buyers do not follow through on their inspector’s recommendation to have the sewer scoped. Some inspectors encourage their clients to get it done during the time of the inspection and sort of kill two birds with one stone in terms of time.

Other things that might need further evaluation outside the inspection include: property easements, clear title, neighbors, wood destroying insects, retaining walls/fences, trees, swimming pools, abandoned or used tanks (septic oil etc), wells, lead, asbestos, water quality testing, radon testing, conditions of the electrical system, conditions of the plumbing system, HVAC equipment issues, energy efficiency, indoor air quality, foundation/drainage issues, chimney issues, roof issues, window/cladding issues etc.

Basically anything that requires further evaluation, because it is either outside the scope of the inspection or outside the inspector’s areas of expertise, should be followed through with in order to do ones due diligence, but many merely see the inspection as completing that regardless the recommendation for further evaluation.

The bison in the china closet in all this is the enormous pressures present to “keep-the-ball-rolling” to closing. There simply is not enough time for a buyers to do their due diligence, so all parties to the transaction encourage seeing the property inspection as the final step in the process—the last big hurtle to vault over or limbo under.

In a seller’s market a lot of the blame for accepting shorter and shorter due diligence comes right back to the buyer—and of course their agent who support the idea as the only way the buyer has a chance of getting the house. Being more or less forced into this arrangement, it is only natural the buyer would expect perhaps a bit more of their home inspector than any home inspector can deliver.

It really is a no win situation for the buyer and they best find a home inspector that gets them as close as possible to all the pertinent information—and perhaps one that has the experience and is willing to guess a bit on their behalf.

You know the client has unreasonable expectations of the inspector when the inevitable question arises, “Would you buy this house?” It is actually quite a reasonable question in light of the position the buyer has been placed, it just does not have an answer unfortunately.

As a side note, and perhaps a topic for a post of its own, a buyer should never rely on an inspection report provided by a seller.  Use it as information on top of an inspection you procure on your own, but do not rely on it for your own due diligence.

Let the bison roam, and fix the yard afterwards.

Charles Buell, Real Estate Inspections in Seattle