I have a propane tank fueled BBQ grill (which heats to around 300 F.)  I also
have a covered porch with a nine foot ceiling that is made of vinyl. 
Will cooking on the porch, and the rising heat cause the vinyl to
warp?

Hello wondering99-ga,

As far as grilling under a porch or patio covering, the answer is
ALWAYS... that it is a bad idea. No matter the height or material it's
made out of, there's always a fire or warping risk.

"Grills radiate a lot of heat. Be sure to keep your grill at least ten
feet from any combustible materials, including the house garage, deck
rails, etc. Never use grill indoors or under a covered patio."

McCormick's Grilling Safety
http://www.mccormick.com/content.cfm?ID=10907

"Be sure you have adequate ventilation wherever you are grilling to
remove deadly carbon monoxide that is formed by the fire. never grill
close to the house, a camper, under a patio or other structure. Place
the grill away from dry or dead grass, bushes and the house."

Grilling Tips, Tricks, and Recipies
http://www.chefnorm.com/grillingtips.html

Google Search
Grilling under a patio
://www.google.com/search?num=100&hl=en&c2coff=1&safe=off&q=grilling+under+a+patio&spell=1

If this answer requires further explanation, please request
clarification before rating it, and I'll be happy to look into this
further.
Nenna-GA
Google Answers Researcher

---

Request for Answer Clarification by wondering99-ga on 13 Oct 2004 14:34 PDT

I was really looking for specifics from vinyl manufacturers.

---

Clarification of Answer by nenna-ga on 13 Oct 2004 15:17 PDT

Hello again...

Let's think of this in a climate sense. While vinyl is used in
climates such as the midwest for homes, you rarely see it in climates
such as the southwest. This is because vinyl can warp under the sun at
the tempatures that are reached there...100-120 degrees in the shade
during the summers.

Think about how far away the sun is to your home.... compared to how
far away your porch is from your BBQ. You'll be opening a lid,
releasing air heated to 200-300 degrees, over and over. Not to mention
the heat rising off the grill as you cook, lid open or closed.... It
most definatly will warp over time with heat.

For example, they reccomend not painting outdoor vinyl with a dark
color, because the heat that the dark paint can absorb can warp the
vinyl. That's going to be much less than the 200-300 degrees your
grill will put out. Also, with the opening and closing of the grill
lid, you'll have a lot of heating and cooling, or expanding and
contracting of the vinyl, which will also cause warping over time.

Not to mention, grilling under any covering is a fire hazard.

This site mentions that vinyl warps at about 140 degrees

"During the summer months, it?s not uncommon for the surface
temperature of your windows to reach 140 degrees Fahrenheit. Know what
happens to vinyl at this temperature? It distorts and warps."
http://64.233.167.104/search?q=cache:BKkNH8Z9Dv4J:www.radiocopy.com/copy/glass.htm++temperature+at+which+vinyl+warps+-record+-records&hl=en&start=9

I hope this explains things further for you.

Nenna-GA

Probably.

Yes, your siding will definately warp.  This exact same thing happened
to me this summer.  I purchased a nice size grill and placed it on my
deck.  Not very close to the siding, but it was still by the siding. 
After a couple of uses, the siding started to warp.  You can
definately tell we used the grill on that spot.  I do not recommened
you using your grill close to the siding.