A sagging roof
is a worrying sight for any homeowner. Roofs are supposed to be straight, so
when they sag it can point towards several different issues. While it's not
something you want to deal with, it's not an uncommon issue, especially among
older homes. This is a guide on everything you need to know about the problem,
including how to fix a sagging roof.

What is a sagging roof?
When a roof has
a curved or wavy appearance as opposed to a straight one it often points
towards a sagging problem. Sagging is a common roofing problem that appears in
homes with roofs that haven't been replaced in a long time due to a
deteriorated structure. They are also a common problem in
older homes due to the way roofs used to be designed.
In terms of how
much roof sag is acceptable, just about any sagging is bad. A roof should only
sag if there is any weight on it. Even then, most roofs should be sturdy enough
to handle the added weight without sagging, so sagging when weight is applied
can point towards a potential problem in the near future.
Causes and Prevention
When a house
roof is sagging there can be a wide variety of things that cause it.
Water damage
is often a common cause due to the damage it does to the sheathing. If your
roof isn't properly distributing water away, then the excess moisture can cause
roof seething to rot or decay which then leads to sagging. Replacing the sheathing
with new material might be necessary in order to fix the issue.
Using
undersized materials is another common cause of the problem. Something as
simple as using 2x4 rafters instead of 2x6 rafters can cause it to sag. If
there is no internal bracing or insufficient bracing, then the walls are
vulnerable to spreading which will cause sagging as well.
An excessive
amount of weight on the roof can also weaken the structure and cause
structural damage due to the stress. It's important to routinely clean snow and
ice off to prevent a large build-up from accumulating. While most roofs are
designed to withstand heavy snowfall, an excessive amount can have a negative
effect on the internal structure weakening it. You should use a plastic roof
rake to routinely remove snow from the roof after heavy snowfalls. It's
important to use a plastic one to reduce the chance of causing damage to your
shingles.
Simple old
age is sometimes the only cause. While proper maintenance of a roof will
ensure it lasts a long time, sometimes old age can cause the structure to break
down and start to sag. At this point, there isn't too much that can be done,
and it might be time to call up a pro to get
the entire roof replaced.
How to Fix a Sagging Roof
Fixing a roof
that is sagging isn't an easy or quick task by any means. If you're not
confident about how to fix a sagging roof on an old house or any house in
general, then it's a good idea to call up a professional that knows about
sagging roof repair.
If you're
trying to figure out how to fix a sagging roof on your own, here is one way to
go about it.
Steps on how
to jack up a sagging roof:
First, attach 2
chains from one side of the wall to the other side using lag screws with large
washers. While it's possible to just use one chain, it might be better to use
two that are spread out evenly in order to spread out the force in case they
try to move away. Then, add a turnbuckle between the chains in order to adjust
the tension on them.
Use a jack-and-post
system to slowly jack up the ridge beam. Set up two jacks and posts so that
they're evenly spread out from one another in the middle, below the roof ridge
beam. Slowly jack up the roof ridge and then tighten the chains each time you
jack it up. Continuously repeat this process until you are done. You should
only jack up the ridge 1" per day since anything more than that can cause
damage to your roof structure. As you can see this is not a fast process and it
can take up anywhere between 1-2 weeks to fix it.
In order to
prevent it from sagging again, add ceiling joists or rafter ties if you don't
already have them. They help provide extra support to the rafters. You can also
provide support to the ridge if you add two 2x4 boards on top of the ceiling's
joists and nail them directly to the ridge. This is one of the most common ways
on how to fix a sagging roof ridge beam.
If all of this sounds like Greek to you, call
770-516-5806. Locals with a sagging roof in Georgia can call us to safely
handle this problem.