Any reason one can't use 4" PVC sewer pipe for dryer exhaust piping?
I've got to go UP 8 feet (which will be metal), then horizontally about 20'
to get to a soffit. For the 20' run I'm considering the sewer pipe (not the
kind with holes) because it's easier to work with.
Goblin roofers didn't replace the roof vent when they put in a new roof, I
didn't notice their failure for a LONG time, and now I'm endeavoring to
correct the problem. I figure a soffit vent is going to be easier than
dealing with a retrofitted roof vent.
Combustibility, lint and static electricty. Sounds like a fun
Here's something pretty funny that I found at
First the author (a "Nationally Syndicated Newspaper Columnist") says
there is no reason you can't use PVC, then adds that the manufacturer
might not want you to because it's combustible! So, according to him,
unless your specific dryer manufacturer says not to use PVC, it's OK.
"I have had to use four inch PVC pipe on occasion to vent dryers
through roofs. ... There is no reason why you can't use plastic pipe to
vent your dryer unless of course the manufacturer says not to. When I
did it, there were no restrictions as to using PVC material. There is
an outside chance that a manufacturer may not want you to use it
because the pipe is actually a combustible material. I would talk to
the local fire department and see what they say......"
Well some places sell cheap plastic flex hose for driers. That is a bad
idea. They collect lint nicely.
The idea that it is OK because the manufacturer did not prohibit it, is
a very poor argument. How many of you have ever read not to put water in
the fuel tank of your car rather than gasoline? They can't predict all the
foolish things people will think of.
As for PVC, I really don't know. I can see some advantages, but I also
see some potential problems. Considering using standard materials works and
the possible results (like death) for using the wrong materials could be
serious, I will stick with standard tested materials.
Manufacturers have to allow for every possible
stupidity and lack of maintenance. I have used the
plastic flex hose and it works fine; I clean the
duct and the inside of the dryer housing
periodically. Currently replaced the split
plastic with thin metal flex, primarily because it
was cheaper. A normal operating dryer isn't
going to cause a problem, but if you use
corrugated anything you have to clean the piping
as it collects stuff. If the lint catches fire,
it will burn or melt the plastic.
I don't see the OP's sewer pipe causing any
problem since the temperature will be down as it
would be 8 feet away from the source. OTOH, a 20
foot horizontal run is a concern unless he has a
booster fan in the tube.
Never had a dryer that wasn't located close to an
outside wall, usually 2-3 feet of tube to the
outside. I would consider moving the dryer so
that it would be next to an outside wall; sounds
like a poor house design. But then I wouldn't
consider an AC unit in the attic, a non-vented
stove exhaust, seven smoke detector tied together,
and a whole lot of other ill conceived ideas.
You are at or exceeding the maximum distance for residential
dryers. Check your particular model. Each fitting and turn
require a reduction in distance.
There is some good information here:
but you might note they do NOT recommend PVC due to static/lint
A live Singing Valentine quartet,
Plastic is combustible
Recently replaced our flexible plastic dryer hose with a flexible
metalized one. Although our insurance companies require metalized as
part of new installs they do not necessarily tell you to replace the
plastic of existing installations.
Our flexible hose connects to a length of galvanized tin pipe duct
identical to that used for gutter drains. The thin Al of the new hose
is very delicate and perforates more easily than the plastic skin of
the old flex. hose.
BTW you can get light weight aluminum some of which comes flat with
edges that you snap together into a pipe after trimming it to length
with metal shears. Also there are 45s and 90s that are completely
rotatable which makes offsets and other angles such as getting over a
truss joist or into a soffit area much easier. We used that for our
One thing we found with bathroom exhaust duct in cold attic was
condensation; it may be wise to slope exhaust pipe downwards toward
outside. In cold weather a little 'beard' of frozen moisture appears on
the lip of the exhaust outlet. That moisture can drip through joins
onto ceiling insulation and ceilings. However the hotter exhaust from a
clothes dryer may avoid this.
I was really afraid of fire from that cheap white plastic durable
flexible easy to use vent pipe thats no longer on the market because of
a friend replced his with the new junk foil type.
i brought his old line home it was in his trash and tried setting it on
fire on the driveway.
it wouldnt burn. at most it might support combustion barely.
even with direct ignition from my mapp gas torch it wouldnt go on fire
just smolder and go out immediately when torch was removed.
personally i think it was safe.
kinda disappointed me with fire hose at ready nothing to put out:(
| > I was really afraid of fire from that cheap white plastic durable
| > flexible easy to use vent pipe thats no longer on the market because
| > fire risks.
| > a friend replced his with the new junk foil type.
| > i brought his old line home it was in his trash and tried setting it
| > fire on the driveway.
| > it wouldnt burn. at most it might support combustion barely.
| > even with direct ignition from my mapp gas torch it wouldnt go on
| > just smolder and go out immediately when torch was removed.
| > personally i think it was safe.
personally I think you are a dumbass for giving lousy advice.
ever hear of static electricity igniting lint trapped in the plastic or
I have seen it burn down many rooms and/or houses in the last 25 years
| > kinda disappointed me with fire hose at ready nothing to put out:(
be careful with that hose out in public.
your picture could end up at the post office with all the other sex
| > personally I think you are a dumbass for giving lousy advice.
| > ever hear of static electricity igniting lint trapped in the plastic
| > flexible ducting.
| Bull! Static electricity causing lint to ignite is
| in the same category as static electricity
| causing fires in home workshops and cellphones
| starting gasoline pump fires.
yes it does and yes I have seen it burn down many homes over the years.
also have seen vacuum systems with plastic pipes ignite.
the only way to stop static electricity from igniting in plastc pipes is
to install a bare copper wire in the pipes grounded to the unit and
grounded to each tool.
do not try to dis-credit my knowledge
for what I say is factual.
watch myth busters
haven't you seen that episode?
the static electricity that is on your clothes from sliding off fabric
seats causes static electricity to ignite the gasoline fumes while
and yes it did catch fire.
so there ..................Mr Bullthon
Must live in area with a very high proportion of
stupid people to see so many homes burn down,
regardless of the cause. (or you are very old).
Yeah, that will work.
Suggest that you point to a government source of
Igniting gas fumes with static electricity is
entirely different from igniting lint. And cell
phones do not cause fires at gas stations.
Yes a few, very few cases of static electricity
igniting gasoline fumes while fueling vehicles at
commercial pumps are documented. Caused by the
person getting back in the vehicle after fueling
started. Easy to fix, don't get back into the
vehicle until you hang up the fuel nozzle!
I cannot speak to the results you got in this specific case but the
general concern is that the smoke contributed rating of plastic ducting
is extremely high and that the resultant smoke is far more poisonous
than that given off by ordinary combustibles. The "form of material
first ignited" is likely to be cotton lint rather than the ducting itself.
Well we aren\'t no thin blue heroes and yet we aren\'t no blackguards to.
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