Here's a brain teaser for home inspectors or anyone else who wants to take a stab. This has to do with roofing and attic.

The home is 8 years old.

There are a few nail pops in the roof covering, but not enough to cause concern.

The roof covering is asphalt shingles in good condition.

The sheathing is exposure 1 plywood.

The sheathing WAS NOT rained on between the time of installation and covering.

The spacing of the sheathing is done properly.

The roof structure is engineered roof truss with no defects in deflection, nor any cut trusses.

Attic ventilation is more than adequate, with soffit and gable vents with turbine assist.

Bath and other exhaust fans are properly installed, with no venting into attic.

All flashing is perfect, drip edge installed properly on rakes and fascia trim.

The roof has never leaked.

The problem:  The roof is "wavy", bumps and rises in the sheathing.

The question is, "why?"

Have fun!!

 
Posted by Jimmy Breazeale on 04/30/2007 11:59 AM   Comments (14)   roofs, attics, inspection defects  
Generate short URL

14 Comments on Brain teaser

APR
30
2007
 No base sheet installed. Sheathing not properly nailed. Truss not installed as per spec. Trusses not manufactured to spec. Uplift of sheathing by hurricane. That's a few.
4:34pm • #1
Good try Mitchell! And all very good reasons, but not the answer in this case.  I'll give one more hint.  There are water stains on the sheathing, but none at all on the truss members, or anywhere else you would expect to find water marks.  I'm probably giving it away now.
4:58pm • #2
No drip edge. Improper flashing. Sheathing warped due to water damage.
5:04pm • #3
Sheathing warped due to water damage prior to installation.  Builder trying to get by cheap.  He had added blocking between truss members (salvage 2X4s) for extra nailers, but it warped anyway.  I should have given the blocking as the hint to make it harder for ya!
5:23pm • #4

Jimmy

Hopefully others will read your brain teaser and realize that we have to go through a process to come to the most correct answer.

5:28pm • #5

Hey pretty good Jimmy.

Do that again but wait for more answers.
8:50pm • #6
LOL~!! Hey, Bob, I couldn't leave Mitchell hanging!!  Amen to what you said, Mitchell.  It was the extra blocking for nailers that made me suspicious, and it didn't take long to figure out the water marks on the sheathing didn't jibe with the lack of same on the trusses.  I asked the owner, and it turns out he knew about it from the git-go, and allowed it to save a little.  The builder had purchased the sheathing at salvage prices.  Wonder which one of them got the biggest break? :) Builder nailed the heck out of it, literally forcing it to lay down, but a good bit of it warped anyway.  Funny thing is, with nails every 4" he might actually have gotten away with it had he let it completely dry before installing it.
10:07pm • #7
MAY
01
2007

Jimmy,

"Attic ventilation is more than adequate, with soffit and gable vents with turbine assist."

IMO, I have seen sufficient data to support that a properly ventilated attic only utilizes properly sized soffit and ridge vents. The use of gable vents and turbines can actually "short circuit" the ventilation process.

 Again, IMO.
6:51pm • #8
That was a good one!
6:53pm • #9

Bruce is right and a very common misconception is that "more venting is better venting". Don't think that they can improve ventilation of your attic by installing vents all throughout the roof surface. You'll fall victum to a ventilation breakdown.

Let's say you have a full soffit/ridge vent system installed. But...by  thinking that more is better, you decide to install a couple of vents about halfway up the roof slope. Instead of improving your ventilation, you have now hampered it because air is now exiting out the vents in the middle of the roof, before it reaches the ridge leaving the attic partially unvented.

Depending on wind speed and pressure, air will also be drawn in at the intermediate vents reducing the intake at the eaves...which is really where it should be.

Keep your system balanced.
7:39pm • #10
Thanks for that info and input, guys.  Point well taken.  I'm a big proponent of the continuous soffit and ridge venting, as I think most everyone is these days.  Don't y'all just love the investigative part of this job?  I like to say that a home tells its own story.  Sometimes, they're downright funny. I am especially fond of homeowner "electrical improvements", and additions that create one of those double-valley, double-gabled, flat drain planes!
9:44pm • #11
OCT
01
2007
1,403,370 Points 7 Featured Posts Localism Sponsor Outside Blog Called Shot Master

Howdy Jimmy

Sorry I got here so late. To have my brain teased.

Have a good one

Dale
6:44pm • #12
DEC
26
2010
630,902 Points 5 Featured Posts Localism Sponsor Outside Blog Called Shot Master

Hi Jimmy

It has been a long time, hope you are well.

C&C
6:50pm • #13
630,902 Points 5 Featured Posts Localism Sponsor Outside Blog Called Shot Master

Hi Jimmy

It has been a long time, hope you are well.

C&C
6:51pm • #14


Spam prevention

To submit the form,
drag the eye to the circle on the side.

Image?id=eecbada96eae9595e4336f7469f836186127637b Image?id=f863750a707c688ed935caa527702a852acb4c61 Image?id=038f49d24591d65aada9d61e8a67a98702fc4029 Image?id=0038d87bbbe0ac2570775b04d79baafe70f1fa70 Image?id=8897bce1c48d8c98c59b4e41b1ec51834449dc56

Accessibility option: listen to a question and answer it!

Type below the answer to what you hear. Numbers or words, lowercase:
Leave a response…

(optional)
Spam prevention

To submit the form,
drag the graph to the circle on the side.

Image?id=6a50bf9439334795ee2a28793facce48cd34c2b7 Image?id=db35c1ce476f88b8c621ea9d773a764b4ffca981 Image?id=7af954504e2225e61446eff19e2b0aba3ef7ffce Image?id=5ffb5864ebefd74eea80c7edebde5e0bdda0c69a Image?id=92187c71aaf06f9e15b3f55089a5e60c4bb87136

Accessibility option: listen to a question and answer it!

Type below the answer to what you hear. Numbers or words, lowercase:
 

Jimmy Breazeale

Coldwater, MS

More about me…

Sherlock Home Inspections

Cell Phone: (662) 417-3194

Email Me

Informative narratives on many subjects, from home maintenance tips to issues of common concern to home inspectors and real estate agents.


Links

Archives

RSS 2.0 Feed for this blog