Improving acoustic ratings for partitions and floors depends on
increasing sound transmission losses to minimize unwanted air borne and
structure borne sounds between adjacent spaces. Effective noise control
improves functionality of building spaces.
Visit our website at http://www.conspectusinc.com/publications.htm
to view or download C1010-Acoustic Ratings 10.03.01. Each Tech Tips file is
titled using the UniFormat system and assembly designation to facilitate filing
and future reference.
Share your opinion about this month's Tech Tips, by leaving a comment,
here.
CSI's specifying practice group discussed the concept of
outline specs and came to the conclusion that traditional outline specs will be
replaced. Most of the group members admitted they seldom produced or used
outline specs. When they do write outline specs, most are not using traditional
methods. Surprisingly, the overwhelming majority favored replacing outline
specs with preliminary project descriptions. So what do you think? Leave a
comment by signing in at the end of this posting.
So what do you think? Leave a comment by signing in at the
end of this posting. Then join the
group to receive notices of future meetings. It is FREE and it is not just for specifiers! Visit the CSI blog for more
information on this and previous practice group discussions.
Here is the presentation that prompted the discussion. The rationale for the poll results follows. Scroll
through the presentation using the arrow button below.
It is often difficult to produce outline specifications that
are consistent. All design team members do not use outlines based on the same
system and engineers prefer to use narratives rather than outlines to describe
the building systems. Tom Gilmore of Torti
Gallas and Partners, Inc. in Denver, CO, has solved this problem by
creating a single spreadsheet with all the standard text for all disciplines.
Each paragraph is a separate row. The text is selected for the particular
project by using Excel's Auto Filter function and then the text is modified as
needed.
Beware that your design contract may require outline specs
as a Design Development deliverable. AIA B101 - Owner Architect Agreement
ยง3.3.1 explicitly requires outline specs as one of the phase services. B101
does not define what constitutes an outline spec. So there may be some latitude
for architects within the bounds of accepted practice.
The group explored several examples of outline specs. CSI's
Project Resource Manual provides guidance on the format for producing the
outlines and shows an example illustrating some of the concepts. Masterspec and
SPECTEXT, two of the commercial spec systems available do not follow the same
format of the PRM example. This has caused confusion about what form an outline
spec should take.
Steve Lawrey of Vitetta
in Philadelphia, PA reported that outline specs are normally throw-away
documents. After they are produced, they are little used and the content must
be recreated when the construction specifications are written. Creating
information once and sharing the result should be the goal rather than
duplicating efforts.
Two alternatives to traditional outline specifications were
discussed: Multi-Purposed Specifications and Preliminary Project Descriptions
(PPD). Multi-purposed specifications rely on using a single document to produce
outline specifications and construction specifications. For outlines, most of
the document text is hidden, showing only text that is relevant to the current
design stage. As more information is developed, more of the specification text
is revealed, until the final construction spec is issued.
Preliminary project descriptions offer an entirely different
approach. Using UniFormat, the project description is arranged by system and
assembly instead of the MasterFormat divisions and sections used for
construction specifications. PPDs offer flexibility to describe multiple
options for the same assembly and the ability to document the reason for
selecting one of the options as the design solution. PPDs can be used
throughout the entire design process to capture the result of the process. Then
they can be used as a quality control checklist against the resulting
construction documents.
The consensus was clear. The group favored PPDs as the
preferred method to document projects during the early design stages. Clifford
Marvin of KPB Architects in
Anchorage, AK, a member of CSI's PPD Task Team pointed out that a PPD Guideline
is in progress and wholeheartedly recommended PPDs in place of outline specs. Download
the draft guideline
from the CSI website.
Yesterday we had the pleasure of hosting Bill Murphy from
Parksite for a lunch & learn seminar about Air and Moisture Barriers for
Commercial Buildings. Waiting for the last slide of the presentation made the
presentation worth more than advertised.
The slide contained this photo showing an installation with
Tyvek Commercial Wrap. The program discussion was diverted by the fastener used
to secure Tyvek to the substrate. The photo shows an installation over a framed
wall with gypsum board sheathing. Tyvek requires mechanical fasteners with
washers to be used with gypsum sheathing. This detail prompted a question about
being able to use Tyvek over masonry and concrete with similar mechanical
fastening.
For past projects, we struggled to find a simple solution
for multi-story residential continuing care and multifamily housing projects
where the lower floors were masonry veneer over masonry backup and the upper
floors were siding over framed backup. This condition typically required two
different air barrier materials and a transition detail to maintain the
integrity of the barrier. The air barrier at the lower floors often
transitioned to a waterproofing membrane which required another product and
another transition.
We learned that Tyvek is capable of solving the problem and
eliminating the transitions. Tyvek can be installed over gypsum sheathing and
over masonry or concrete, the only difference being the fastener. In addition,
Tyvek accessories include flashings to make transitions to waterproofing
membranes.
None of this discussion was part of the prepared
presentation. The photo provided a valuable opportunity that will help our
clients solve a persistent problem. Our staff and friends learned something new
that will have immediate and practical use.
Conspectus shares lunch & learn presentations with our
clients and friends that are interested in joining the discussion via our WebEx
account. We have a limit on the number of participants that we can accommodate
so reservations are required. If you wish to receive notices about the lunch
& learn programs we host, please send an email to bbushay@conspectusinc.com and ask
to be added to our notification list.
