- Today, we're talking about ventilation
for standing seam metal roof applications.
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Welcome back to the standing seam metal roofing series
on the Metal Roofing Channel.
I wanna talk today about ventilation.
Certainly, if this is your first video
or if you've missed any, you can check back
on any of our other videos that we've done
for the standing seam metal roof design series.
Otherwise, jump right in.
Today we wanted to talk about ventilation
specific to standing seam metal roofing
and really focused on, so you've got a metal roof.
You've worked with your ventilation expert
and you wanna move this project forward.
You know, there are a handful of different ways to focus
on the ventilation, and what would be appropriate
or specific to a particular project,
so we wanna talk about that a little bit today.
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- So there's two main ways to vent your roof system.
They're both gonna involve a ridge vent, a vented ridge,
but one involves attic space
and one involves vented roof sheathing.
When you're venting an attic space,
you're gonna have a soffit panel
that's gonna bring cold air up into your attic space,
and it's gonna release the hot air out
through the vented ridge or hips.
Your roof sheathing, when that's vented,
you're gonna have usually some type of rigid ISO
with a batten, and then a nailable substrate on top of that
that you're gonna attach a metal roof to.
You're still gonna use a vented ridge system,
and then you're going to have either vented material
behind the fascia of the roof system
or behind the drip edge of the metal roof.
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- So with those two kind of design criteria in mind,
you know, what other things should we consider
when you're looking at venting through the attic
or venting through the sheathing?
- Well, you know, the first thing you wanna do
is make sure that you're using a good venting material.
There's a lot of different products out there
and there's a lot of different ways to install them.
There's venting product material,
I mean, the whole idea is to get the air
into and out of the roof system.
There's many ways to do that,
some work, some are absolutely not recommended.
You know, one of the absolute not recommended ways is
perforations or holes in your Z closures.
Completely ruins your weather tight capabilities
and it's just, you don't know how much air flow
you're trying to move or anything like that.
So there are products on the market
that are designed specifically for venting metal roofs
or the eaves systems of metal roofs
if you're using an above sheathing ventilation system.
They're usually layered, and different layers,
so it has small holes,
so it's harder for water to drive up in there.
The ridge cap flashing usually covers
the area where air enters,
and in certain areas that might have a lot of heavy snow,
they have products with what they call
an enhanced snow screen on the front of those baffles
to stop anything from driving up through there.
The venting material usually is gonna install
directly on top of the Z closure,
so you're not losing any of your watertight integrity
through your Z closures,
you're just adding a piece to the assembly.
So you have your Z closure, you have an air dam
which is a little piece of metal that comes up
and if any water or moisture was to get through that,
the lip on the metal catches it so it could evaporate.
And then the venting material goes down
and your cap goes on over top of it.
How much venting material and how often you should use it
is gonna be based on the calculations you've designed
on how much air needs to move out of the attic
per your requirements.
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- If there's somebody that has a roof system
and they need to move more air,
are there other options for additional ventilation?
You know, let's say specific to the attic
that wouldn't impact the integrity
of the standing seam metal roofing system.
- Well, you can vent more of your ridge,
you can vent your hips.
When it comes to, you know, say,
mounting, you know, turbines and things like that,
we don't necessarily recommend them because
now you're creating penetrations in your roof system,
you know, any penetration has the possibility of leaking.
Again, using the products that are designed
for the ridges and the hips is gonna
probably be your best chance of minimizing any, you know,
loss of watertight integrity into your roof system.
- So it sounds like if you have
an attic ventilation situation,
would you rather vent out of the gable side
with a louver or something like that,
or would you, you know, recommend that
versus a penetration?
- Yeah, I mean, when it comes to metal roofing,
the less penetrations, the better.
And if you have the option of using, you know,
a louver on your wall or something like that
to let air flow in, you know, it's absolutely possible
as long as it meets your design criteria.
If you don't have that option, again,
I go back to, you know, venting the ridges of the hips
is gonna be the most applicable way of
accomplishing what you're going for.
- Okay.
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So I think it's pretty safe to say that
ventilation is really one of those things
that's project-specific,
it's not one of those things that's one size fits all
or a cookie cutter scenario.
So, you know, when it comes to venting requirements
per project, per design,
obviously we can help support, you know, the details that
are required for a successful standing seam
metal roof installation,
but it is important to work with the ventilation experts,
both on the product side and the design side,
you know, we can certainly help guide to both.
- Yeah, absolutely.
I mean, the ventilation experts are just that,
they're the experts,
they're the ones that are gonna, you know,
help you determine how much air flow you need
and the different options you have in accomplishing that.
It's important to remember
when you're working with those people
and you're designing with a metal roof
with a certain manufacturer or, you know,
you're gonna be asking for a weathertight warranty,
you wanna make sure what they are telling you
is going to incorporate
and be accepted into a weathertight warranty system.
So you're not designing something that
is outside of the scope or won't be, you know,
able to be approved for a warranty.
- Yeah.
Well, I think that about wraps it up.
Stay tuned next week while we cover underlayments
and design consideration for underlayments
in your standing seam metal roofing systems.
If you haven't subscribed yet to the Metal Roofing Channel,
please do,
and check out future episodes as well as past episodes
of the standing seam metal roof design series.
Thank you.
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