First time on this forum and I hope that you might be patient with me. We
have hired a licensed contractor to build our 4600sq. ft. home. I am not a
contractor nor am I experienced in any terms used in construction so much of
what is happening goes straight over my head. But I am hoping someone on
this forum might explain what our options are to the following....
Apparently our trusses company is working on another home at our elevation
about 1/2 mile away. They came and asked our general contractor (GC) why we
didn't need snowload trusses for our house since the one they're working on
now had to have them. So GC called code enforcement and this is what he found
out... it looks like our licensed architect (LA) didn't know that at 4300
elevation we are in a snowload zone. I know this zone code covers from 3300
to 5400 elevation but do not know the load amount it should carry. Anyway,
the LA didn't design snowload trusses into our plans. Engineering didn't
catch the mistake and neither did our County Permit Department. But now...
it looks like we might need to remove our roof and if I understand correctly
put on different trusses! GC has pulled his crew off the house until this
can be resolved so all work has stopped. At this point other companies have
done their work, the roof is felted. HVAC, central vac, plumbing, electric
wiring all in. Much of this runs through the existing trusses.
A meeting was held by the GC, LA, the engineer, and County to see what
measure might be taken. GC has come up with the idea of possibly
retrofitting our roof based on the current snowload code using calculations
at 200 feet elevation increments instead of the entire 5400 elevation. If
County approves this plan on Monday, it will go to engineering to figure out
exactly how to do this and then back to County for final approval. Can
someone enlighten me if this is a safe solution for this problem or at least
explain exactly what I need to concern myself with to make sure this is
handled properly? I sure don't want the roof to collapse onto of my g-kids!
If I understand this correctly, and I'm skeptical that I do from your
description alone, it sounds like the code is applying the worst case
snow load that would exist in the 3300' to 5400' elevation range, which
would likely be that at 5400', to the entire range of elevations. It
sounds like your GC is asking if they can instead interpolate the snow
loads between the value at 3300' and that at 5400' to get a value for
the actual elevation of your house which is 4300'. This seems
reasonable to me, but is certainly less conservative an approach. So,
for example, let's say the snow load at 3300' is 20 psf and at 5400' it
is 40 psf (I'm just making up these numbers for illustration!). Since
4300' is roughly halfway between 3300 and 5400, a linear interpolation
would suggest that the appropriate snow load for your house would be
about halfway between the upper and lower snow load values and thus
would be 30 psf. Since your trusses don't meet the 40 psf required by
code for this entire 3300-5400 range, but might meet the interpolated
value of 30 psf, this approach might let you get by.
Is this safe? Probably, but it all depends on how close to linear the
actual snow fall averages are between 3300 and 5400 feet. There may be
other options available that a structural engineer could devise that
wouldn't require replacing the roof. It may be possible to sister
members to the existing trusses. Trusses typically assume no
load-bearing walls in the span. However, if your floor plan happens to
have a wall that runs perpendicular to the trusses and is near the
center of the truss span, it might be possible to install a king post in
the trusses and transfer load to the wall and effectively halve the
length of the trusses. This would limit future remodeling, however, as
you can't easily move a load bearing wall later.
It is pretty sad that your LA and engineer aren't providing solutions
and it is resting entirely on the GC. However, it sounds to me like
your GC is pretty sharp as his idea seems to be reasonable to me.
However, I'm a structural engineer in training (halfway through my
masters degree), so don't take my comments too seriously. :-)
Maybe Bob Morrison will weigh in...
I agree with Matt about your GC seeming to be on the ball. His idea to
interpolate the loads is a reasonable approach, but whether the powers
that be will accept it of not is another story.
The snow load is also based on the pitch of the roof. The steeper the
roof the less likely that snow will build up on it. Another factor is
the type of roof covering. A shingle roof is more likely to have snow
build up on it as it is a rougher surface. A metal roof is slicker.
Your architect should be all over this as it's primarily due to their
oversight. There is still enough blame to go around. The truss
company was remiss in asking the question after they had fabricated the
roof and it was already installed. If the builder has experience in
your area he should also have been aware of the likelihood of increased
Permits are frequently issued with errors and oversights on the plans.
It'd be great if it were otherwise, but it's not. Structural issues
are entirely the responsibility of the architect and engineer. You
didn't indicate whether the engineer was the engineer of record and in
the architect's employ, whether you hired him after the fact of if he
is there to cover the county's butt.
There is also a critical question you haven't asked. Loads are
calculated from the top down. If the roof loads are increased, what
does that do to the rest of the structure? Beams and headers might
have to be reinforced, and reinforcements all the way down to the
foundation might have to be done.
You are in a tough situation. Please keep us posted on developments as
As far as my understanding of the situation, I think your explanation of the
psf at different elevations is correct. I believe that is what GC is
attempting to do.
As far as load bearing walls. I have no idea which ones are and which are
not. Our home is very long (at 140 feet) due to our lots configuration. At
it's widest I believe it is only 40 or so feet wide. Would the length help,
hurt or not affect the snowload?
It is sad that the LA isn't taking an active roll in this. In fact, we've
yet to hear from the man.
I don't know if this will help either of you to determine what I'm speaking
about, the pitch of the roof, etc., but you can see a picture of our home at
this web address.....
Reinforcing beams and headers hasn't even been mentioned! I'm afraid to
think about what it would do to the house if this also isn't addressed.....
Well, it's time to shake his cage. Send him a letter asking for an
explanation of how this happened, what he intends to do to rectify the
situation and who he thinks will be paying for the extra work and the
delay due to his ignorance of the code. Do not mention a lawyer or a
law suit. At the bottom of the letter, stick a cc: J. Francis
Hastings, Esq. If they have any sense at all the architect will become
motivated with just that little cc:
Pretty low sloped roof. That's not going to help matters much. Can
you tell us what the architect used for the design load and what it
should have been? That will help us determine the magnitude of the
I am not trying to scare you. I was merely pointing out that an error
in the snow load figure effects the rest of the structure right down to
the foundation. People do not specify structural members that have a
large amount of excess strength. That would be wasteful.
Winter is here, and snow is on the way. You need to insure your
investment. If that engineer is not directly in your employ, you need
to hire a consultant who can review the plans and tell you what needs
to be done. Then it needs to be done sooner rather than later.
I'm not one to encourage the use of lawyers as I think they really
should be a last resort, however, if you don't hear something from the
LA soon, I'd have a lawyer give him a call or send him a letter. This
is inexcusable behavior on his part assuming you've told us the full story.
It is very unlikely that this will be an issue. Most walls and headers
are substantially understressed. The same construction methods and
member sizes are used for one-story and two-story residential
structures. The extra show load is very unlikely to add any more load
than would adding a second story to the house. It wouldn't hurt to ask
for confirmation of this, however, I'd be very surprised if this is an
Wow, that is one convoluted house, no offense intended! The length
isn't a factor in the snow load as the trusses span the short direction
so that is what counts.
Very unlikely? What's your guess on the porte cochere beams, posts,
footings, etc.? I don't know the snow loads, but the design loads
could be off by a factor of two or more. I don't know anyone who
doubles the capacity of structural members just to be on the safe side.
And we've only seen one picture...
I don't know about design loads but I will try to find out for you what he
used and what it should have been.
I agree with the lawyer suggestion and will take it up with DH tonight.
I don't know if this will help to answer any of your questions, but here are
a few more pictures...
I forgot to mention there are steel beams are placed throughout the house.
You can see them on the last picture, taken from inside the house (next to
the bottom windows). I was told this is because we are in earthquake country,
only about 400 yards from the San Andreas fault.
You're right about this house having a complicated design (I assume that is
what you ment by convoluted) .
I can't quite make out what is going on in the space between the
stacked shear panels (the metal "boxes" between the windows. Is the
second floor one sitting on a bunch of stacked horizontal pieces of
wood (aka blocking)? Or is that area a single piece of the beam
material (LVL)? It makes a difference, let me know.
I'm also curious why in another picture the beam is painted white. Why
did they paint it white while they were still framing? Why paint it at
I'm sure they're going to be covered, so what's the point of painting
them? The paint runs onto the metal connectors, so it was done after
they were erected. They only painted the faces. Now what would be on
the faces that would need to be painted over after they were installed?
The use of solid blocking between the stacked panels is okay provided that
all the shear, tension and compression forces have been accounted for.
Fastener end and edge distances are critical here.
The upper panel is probably lightly loaded, but geometric constraints
dictate a certain size panel. (Matt, this is one time when your comments
Bob Morrison, PE, SE
R L Morrison Engineering Co
I extrapolated your comments about using minimum sizes of stuff because it
"It's always done that way." or it is the "standard way". You are correct
in assuming that in some cases that is true, but when it comes to doubling
or tripling the snow load I would not make that assumption. I came down on
you kind of hard in an earlier post on this subject so I was trying to
throw you a bone by way of apology. I didn't make myself very clear in
either post, so perhaps this post will help smooth things over.
In this case the shear panels only come in certain sizes, so the designer
must use what is available in order to meet the geometry constraints of
the space available.
Bob Morrison, PE, SE
R L Morrison Engineering Co
Don't think twice about it. I have pretty thick skin and engineers
can't afford to mince words about things that can cause structural
failures. I didn't even think about taking offense at your comments, or
Rico's for that matter either. I enjoy a good debate and don't take it
personally at all.
I'm glad to hear that, Matt. I toss barbs your way on occasion, but
it's for entertainment value (mine, more than yours I'd imagine!) and
there's nothing personal. We both know you're pretty sharp cookie.
I do wish that this thread were a debate and not a "situation". There
are many things I don't understand about how it seems to be unfolding.
I guess that's the price we pay when there's only one version being
told. I don't think the OP is anything other than truthful, but she
obviously is lacking the complete story and can only give us incomplete
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.