Wood rot is fungal growth in the cellular structure
of wood. It is caused by placing wood in locations where moisture
is present for long periods.
Wood rot can develop undetected in enclosed,
poorly ventilated areas such as crawl spaces. The subsequent
deterioration can lower the loadbearing capacity of framing
and, if not arrested early, wood rot can completely consume
the wood members. Any wood surface with long-term moisture
contact may develop the fungal growth, but the end grain,
where cut wood cells are exposed, is the most susceptible.
Whereas the elimination of the moisture source
will arrest further growth of the wood rot, prevention is
by far the best remedy. This newsletter addresses several
problem areas and the appropriate preventive details.
-
 Wood
Stair Treads Should Not Be Buried in Stucco
Option 1: A stucco screed could be used
to provide vertical separation between the wood stair
tread and the stucco.
Option 2: A wood stringer held away from
the stucco will allow water to flow through the assembly.
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Finish Grade Too Close to Wood Structures
Uniform Building code, Section 2516(c)7,
requires a six-inch minimum separation between finish
grade and wood structures. Less separation poses a potential
termite as well as wood rot problem.
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Wood Star Stringer Deterioration
Untreated Douglas fir is commonly used for
stair stringers that are placed directly on a concrete
slab, and often this practice develops wood rot if exposed
to moisture. The Uniform Building Code, Section 2516(c)7,
requires a decay-resistant, or pressure- treated, wood
for stair stringers placed on a concrete slab on grade.
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Wood Balcony Railings Often Leak into
the Building Frame
Railings often split and warp, generally
offering little protection for the wall below.
An additional layer of barrier paper, or
a product such as "Jiffy Sea," should be installed
over the standard building paper at the top of the wall.
the barrier paper should lap down six inches on each side
over the building paper.
Slope the top railing member to alleviate
standing water.
 All
railing and trim members should be painted on all sides
to reduce warpage and splits in the wood, including fresh
end cuts.
Caulking and flashing should be used at
intersections to prevent water entry.
Note: This newsletter addresses concerns that
relate to some common wood rot problems. There are a multitude
of other conditions that can lead to wood rot damage.
Information provided by Building Analysts, a full-service architectural and engineering firm with many years of experience in construction litigation. Their services include: architectural and structural investigations, repair recommendations, preparation of exhibits and expert testimony. Contact Building Analysts at (619) 234-8153.
© Copyright 2008 The Miller Law Firm. All rights Reserved.
If you experience problems or have questions, contact us at Info@ConstructionDefects.com.
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