Dennis: The two inch clearance thing has been in the code for some time.
Without getting into the logic of the code ( which would cause too much
traffic on the list server anyway), I would just try to avoid using the
fireplace to support wood. However, when necessary, I would suggest that
you design a steel support that will provide for an air space of 2". The
code provides for separation of masonry from wood, says nothing about steel.
There is precedent for this. Prefab. fireplaces have steel spacers to keep
the wood from touching the main fire box. After the Northridge earthquake,
the City of LA published a fix-it guide for fallen chimneys where they
showed a wood surround being built directly on top of the remaining masonry
firebox to enclose a new metal chimney. Good luck.
George Richards, P. E.
From: Dennis S. Wish [mailto:dennis.wish(--nospam--at)gte.net]
Sent: Monday, May 22, 2000 10:47 AM
To: SEAINT Listservice
Subject: HELP: 2" clearance around masonry fireplace
I have a large custom home under construction here in the desert. The framed
patio cover is constructed around a large masonry fireplace. The main girder
supporting the roof framing would pass through the fireplace chimney so I
designed the beams (a Parallam) to bear on each side of the fireplace using
a typical Simpson GLB Beam Seat's. The inspector will not accept this as he
claims there must be 2" clearance between the wood and masonry. I suppose I
can create the clearance above and on the sides of the beam but obviously
I also don't understand the danger of the connection since the firebox is
lined masonry and there is no direct heat source to the wood. I would
understand if the fire came from in front of the fireplace as I can see the
heat and smoke working up the face of the fireplace.
Can anyone clarify this code requirement that the inspector is adamant
about. I am not aware of it. If this is the case, what alternatives do I
Dennis S. Wish, PE
Structural Engineering Consultant
(208) 361-5447 E-Fax