A letter to the owner of the metal buildings

2. Condensation！
Do you have the same problem?

3. The New Year is coming, I hope that
you will all be well and have a wonderful
holiday. As the temperature drops, the
problem of indoor condensation becomes
more apparent. (The colder the area, the
greater the risk of condensation.) As a
person who helps thousands of rooftop
problems and doubts every year, I can
determine one thing. Every year I receive
a lot of phone calls and emails from
homeowners. They are desperate, afraid,
and frustrated. "I installed a metal roof,
and now it's raining in my attic!"

4. In the case of these photos, the
house is a modular unit, initially a
flat roof, where the homeowner “adds
extra” to solve the problem of their
metal roofs, but later finds even
worse – from inside the house The
warm, humid air enters the space below
the metal roof and blocks there. When
the temperature drops at night and the
roof cools, moisture condenses on the
inside of the roof. Of course, this is
not a big problem in the summer, but
it quickly becomes a major issue as
the seasons change.

5. The concept of what is happening here
is very simple, but it is usually easy
to be misunderstood. Most people think
that the condensed water comes from
outside. This is because these problems
tend to be the worst in spring and
autumn, even when the weather cools down
or when it rains often. But the truth is
that warm, humid air from the room is
trying to travel to the dry area, and if
the water vapor rises when it rises, it
will condense. It's very like putting a
cool soda on the porch on a hot, humid
day. Once the glass is taken outdoors,
the moisture in the air will condense on
the colder side of the glass.

6. The special homeowner told me to remove the shingle and laminate a
anti-condensation felt called TEARSTOP underneath the metal plate and
reinstall the roof. TEARSTOP is a fibrous material that retains
moisture and allows it to dry rather than condense. In the narrow
spaces such as the attic in these photos, the use of TEARSTOP anti-
condensation felt also requires additional vents.

7. There are four elements that must work
together to avoid these problems. In some
cases, you may be able to improve the
situation by doing two things, but if you
do nothing or do nothing, you will never
solve the condensation problem. they are:
1. Insulation and air isolation. Through
the insulation on the top of the ceiling,
ensure that the warm and humid air in the
room does not enter the attic.
2. Steam barrier. This will prevent
water vapor from passing from the living
space to the attic. This vapor barrier is
usually best placed directly under the
ceiling and under the insulation.
Occasionally, people ask for a steam
barrier under the roof slab, but all of
this is to move the problem from under the
roof to below the steam barrier.

8. 3. Ventilation equipment. Good attic ventilation brings fresh air to the bottom of the attic
and uses convective airflow to vent it through the vent. When the air passes
through the attic, it will vent water vapor.
4. TEARSTOP anti-condensation felt can
temporarily store water vapor and exclude
moisture from the outside when ventilation.

9. Metal structure roofing is a great and evolving industry. It is necessary to prevent condensation in
metal structures.
Tearstop anti-condensation felt
can effectively protect the metal structure roofing from the problems shown in photographs
If you need our help, please call us at 021-63808772 or visit our website
https://metalbuilding-condensationcontrol.com/html/cn/

10. Thank you