Shingled Roof over front patio

[Michael Scher]

This is architectural composition shingle roof over the front patio. Low slope. Is there something I don't know that allows this installation without underlayment?

Thanks,
Michael
Scher Professional Inspections

[Jim Luttrall]

What is the slope? Have to go by the manufacturer's instructions, what brand?

I strict response to your question though, nothing allows it except the installation instructions (if they do.)

[Michael Scher]

Greetings all,

I realize my original post is a bit ambiguous. Let restate the post to get more feedback. I have less than 100 inspections and I'm looking to the field experience you guys have that is not taught in a book.

IRC905.2.7 -For roof slopes from 2:12 to 4:12, underlayment shall be two layers applied in the following manner...
This application over the patio has NO underlayment installed.
As a side note, the primary roof appears acceptable.

My expectation is, even though I am writing the report for the home owner, I have to be prepared to defend my statements to the builder.
Before I recommend double underlayment be installed according to code, I am wanting to know what exceptions may be in place that allow this to be an acceptable installation.

Thank you for your feedback,
Michael

[John Arnold]

...Before I recommend double underlayment be installed according to code...

I would simply write it up as "no proper underlayment". You don't have to make specific recommendations, at least around here you don't. It's clearly wrong and you have the code to back you up. If there are no exceptions noted in the IRC, then you're good.

[Jim Luttrall]

Micheal, after looking more closely at your photos, I see there is no underlayment visible. So, the next question is slope which is hard to tell from the photos. If it is less than 4/12, then double underlayment is required per the IRC (if that is applicable in your area) and if the slope is less than 2/12 then the shingles are not allowed. Assuming this is a new house, there may be wrappers on site or the brand and type available from the builder for any further guidance from the installation instructions.
Key question then is the slope. There is no exception that I am aware of for porches, etc.

[Jim Luttrall]

One more thing to consider is the flashing around the window... looks a little suspect to me from what is visible in the photo.

[Markus Keller]

Can't tell roof slope for sure however,
Low slope especially needs underlayment. I usually recommend ice/water shield on the whole thing, instead of only first 3'. (first 3' up ice/water shield then continue it or run felt the rest of the way up is Code most muni's around here)
Low slope shingles are produced and sold. From my experience most guys just reduce the reveal on regular shingles. Some manuf install instructions I have read do allow regular shingles to be used in that manner.
The best thing is to check with that manuf and see what they stipulate. I know where many of the supply houses are in my area (not HD) and often times go there for spec sheets on items like this.
What's the deal with all the granules underneath? That seems a bit odd.

[Jim Luttrall]

I usually recommend ice/water shield on the whole thing, instead of only first 3'. (first 3' up ice/water shield then continue it or run felt the rest of the way up is Code most muni's around here)



Good information Markus, but no ice shield here in North Texas, much less in Austin. Although I did see some icy roads in Michaels part of the world a while back.

[Ted Menelly]

No underlayment, no drip edge, uh oh. OOOPs did I say drip edge. That was another thread. I used drip edge on every roof I ever did. Manufacturers specs or not.

Just me

Ted

[Mike Schulz]

The porch roof is usually the last thing put on because the brick masons need to lay there brick. The tar paper gets destroyed and mortar embedded and tears lets mortar under it. The roofers came back and tore the paper off and did a lousy job of sweeping it off. No paper on site so they ran the shingles.

It should have felt installed and if Jerry has anything to say about it, it should have drip edge.........;)

(One more thing to consider is the flashing around the window)

We would install pan flashings with a apron front under windows that where installed at the roof line before the brick row is installed. In our area we where the only ones doing it. Most just caulked the living crap out of it around the brick after they butchered the apron metal to fit under the brick.