I recently moved into a 1929 Craftman Style house where the collar
beams have been removed from at one end of house to provide for attic
storage. I recently noticed that the
rafters are separating. I need the storage space, so does anyone have
any suggestions on how to reinforce that end of the attic so the
rafters do not continue separating from the ridge board?
Put the collars back or replace the ridgeboard with a supported ridge beam
designed by someone who knows what they're doing. Don't forget to get a
If the separation is extensive you probably have damage at the walls where
the thrust force is at work too.
It's stupid to trade off a building's structural integrity for a little
additional storage space. You are killing your house. There are no
Reinstall the collar ties (they are not beams even though in some areas
that is what people call them). There is no other choice. You should
do this yesterday, if you catch my drift.
Have a pro take a look at it before you start DIYing. DIYing is what
caused the problem in the first place. By pro, I mean engineer,
architect or an experienced contractor.
You should look along the exterior walls where the interior walls
intersect them. If there are cracks forming, you need an engineer.
In a previous post email@example.com wrote...
I concur with both Rico and Michael. You have placed the structural
integrity of your house in jeopardy. Hire a local professional engineer
to review the situation and to make recommendations before the house
collapses around your ears.
Bob Morrison, PE, SE
R L Morrison Engineering Co
Lets get real here. If the rafters are separating from the ridge,
I would suggest you contact the airlines and have them see what
that roof has to make it lift up. They will buy the idea. Any
that I have seen seem to push down and get tighter on the ridge.
What you described, the way you described it, can't happen. Is
this a hoax?
The bottom of the rafters' plumb cuts pull away from the ridge as the
walls spread apart. The top of the plumb cuts stay in contact...until
they don't, and then you really should be anywhere else than under the
Winter. Snow loads. Wind not partially blocked by tree leaves. Needs
to be addressed immediately.
Wood does not shrink in length to any degree that you could notice.
Wood shrinks radially and tangentially - width and depth. The rafter
shrinks along those two shrinkage planes. Since the plumb cut is on an
angle with the top restrained, some of the shrinkage has the effect of
shortening the lower part so the bottom of the plumb cut opens up a
bit. This is normal and expected.
I don't think this is the case in the OP's situation since they've only
noticed the gaps in the area where they removed the collar ties.
how long ago were they removed? were they ever actually there? you could
drill a couple holes insert some shackles, hook up a come along & pull
them back in place & put up collar ties or even metal strapping to keep them
intact. it really doesn't make sense that the rafters would push away from
the ridge unless maybe it was jacked at some point in the past. maybe it had
a sag & someone jacked it up to replace posts or such.
hope it helps.
I bought the house in 1982, renovated it, which included leveling the
floors and replacing a large section of the foundation near the end
where the separation is. The attic was used as storage when I bought
it. I did not notice the maybe 1/4 inch separation until I moved into
the house this February, after I renovated it again. This renovation I
applied stucco and again did some foundation work on the other side
(north) of the house where the original foundation work was done. I
also put 2x8 rafters on the storage side of the house to support the
load and new drywall throughout. I had replaced the original roof and 4
other layers of roof two years ago and the house is in so.cal so I
don't have a snow load problem. After 6 months I have noticed drywall
nails (4) popping out slightly on the north side of the house. Could
this be related to the same problem of the ridge? Your idea of pulling
the rafters back or just supporting them seem ideal if I it would work
by doing it, say 5 feet from the ridge or 6 feet from the attic floor.
What do you think?
On Nov 22, 6:19 pm, firstname.lastname@example.org wrote:
Without seeing the situation firsthand, and not knowing if the gaps are
widening, I would advise you to attach collar ties to opposing pairs of
rafter, every other pair, about 1/3 of the way down from the ridge.
Generally five 10d nails into each rafter at each end. This will
prevent the rafters from continuing to separate.
Keep an eye on the situation, and pay particular attention to the
wall/ceiling and exterior wall/interior wall junctions for signs of
cracking. String a very taut line under the ridge board, spaced down
from the bottom of the ridge a half inch or so, equal on both ends.
Measure down to the line at each pair of rafters and see if the ridge
has sagged where you removed the collar ties. If you have a good eye,
you can sight along the bottom of the ridge to get a qualitative idea
of the amount of sag.
If there isn't any cracking in the drywall and the bottom of the ridge
if pretty straight, you've probably caught it in time. Learn to duck
under the collar ties.
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