An architect I
have known for over ten years contacted me a few days ago to help him solve a
problem on a custom home that he designed. The engineer that he used has
worked with him for over 15 years. The home uses Trus-Joist TJI floor joists
that cantilever out to form the balcony at the second floor. He has attached a
rim joist and showed the detail for the sheathing and finish on his plan.
The plan check
agency wants a detail to show how the manufactured glass railing is attached
to the end of the balcony. The Architect showed a conventional lumber balcony
framing and at the end a 4x rim joist. The mullion for the railing was shown
to be bolted down through the center of the beam at some uniform spacing. The
connection is a threaded rod with a plate washer and nut that is recessed into
the rim beam. The balcony framing (whether TJI or 2x) is cantilevered out from
the floor framing. The framing is covered with plywood nailed to the top of
the rim beam and joists. The sheathing is topped with lightweight
The plan checker
asked to show that the beam won't fail when a 200 pound lateral load is
applied at the railing 42" above the deck.
I reviewed his
problem and gave him my opinions;
1. There needs to
be a step down (1 or 1-1/2 inch) from the 2nd floor level to the balcony to
prevent water from flowing back into the house if there is no slope to the
balcony joists (the TJI's are not sloped). This does not seem to be an issue
in the TJI catalogs as it was a few years ago when they had step down joists
or cantilevers designed by extending Microlam's; sawn lumber or Timberstrand
joists extended in the web of the TJI's.
completely, though I have always seen this done with microlams or some other
material that can be notched and / or ripped.
2. I believe that
the sheathing nailed to the top of the beam will prevent rotation in the rim
beam, but I see that if you pull on the railing there would be a possibility
that the connection of the beam to the end of the joists might fail in
pull-out strength of the connection.
3. I suggested he
recommend to his engineer that a Simpson LTT strap be used where the failure
is likely to occur. For safety reasons, I would use on one each joist
alternating between top and bottom so that the rim-beam is tied back to the
joists at top and bottom (where the couple is likely to
are on the right track. I would look at angle clips with bolts between
the joists and rim beam rather than cross grain tension. Or install
straps top and bottom. This is one of those areas where the contractor
will have have a fit with the usual "We have been just bolting the damn things
to the plywood for years....". The problem is that very often these
details are not engineered but are simply provided by the Architect and no-one
questions the validity of the design.
His engineer is
refusing to deal with this issue and the architect asked if I would intervene.
If this were conventional construction, I believe I could take care of the
non-compliant portions of the home, but in this case there is an Engineer in
Responsible Charge who is, in my opinion, required to complete the plan check
>>> Is he
refusing to deal with the issue or indicating that it is not in his
scope? If they have worked together for 15 years I am surprised there
would be an issue now on this project. There might be other underlying
Can the architect
contact BORPELS to file a complaint against the EOR if a permit can not be
pulled until the corrections are complete?
could. Depends on the actual contract obligations and what the "real"
circumstances are. All kinds of nasty litigation could be enacted if in
fact the engineer is refusing to do something he is contracted to do. I
would be very reluctant to go down this road without a thorough understanding
of all the relative facts and positions.
Can the architect
hire another engineer to supply the calculations needed and have the architect
wet-stamp the details and calculations provided to him?
the Architect can hire another engineer for this component and then assume
responsibility under his stamp. Alternatively the other engineer can
provide a rail and rail connection design as a separate deferred submittal
subject to the EOR's approval. This is done all the time for stair and
I don't think this
is such a difficult problem and don't understand why the engineer of record
will not complete the design. I've reviewed his drawings and details and other
than the coordination between the architect, who shows conventional sawn
lumber, and the EOR who specifies TJI's, the drawings are light on details,
but adequate compared to what I have seen out here.
think that for the reasons you describe above, there must be more to it.
The EOR may have had his fee haggled down to the ridiculous and the exclusion
of these detail items is part of the agreement. This is one of the
reasons I try and stay away from residential design. I am always amazed
that the realtor can earn a higher fee selling the place than the engineer can
justify designing it. Custom residential is an art and extremely detail
intensive if it is done correctly. Half of what we see presented as
"engineered designs" is pathetic. The fact that the EOR actually
provided an adequate design other than the rail issue is another indication
that there must be more to it.
state that you are "caught in the middle". I would simply step out of
the middle, present a fee and contract to perform the rail design as a
deferred approval or separate contract, and let the Architect, Owner, and EOR
work out the issues whether or not you are to proceed.
would be appreciated.
Dennis S. Wish,
Caught in the