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Historic Preservation - Technical Procedures

Spectitle:

General Inspection And Maintenance Of Gutters And Downspouts

Procedure code:

0763101S

Source:

Hspg Prepared For Nps - Sero

Division:

Thermal And Moisture Protection

Section:

Gutters & Downspouts

Last Modified:

02/24/2012

Details:

General Inspection And Maintenance Of Gutters And Downspouts



GENERAL INSPECTION AND MAINTENANCE OF GUTTERS AND DOWNSPOUTS


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on inspecting and
         maintaining gutters and downspouts.

    B.   Gutters on older structures cause problems because they
         are typically integrated with the roof structure such as
         built-in gutters, cornice gutters, hidden gutters and
         Yankee gutters.  Hung-gutter types are more common on
         newer structures.

    C.   A failed gutter often means that damage has spread= ;
         repairs will be extensive, maybe complic= ated, and
         probably expensive.  A well-restored gutter, however,
         faithfully maintained, should require no major attention
         for decades.

    D.   Downspouts, flashing, conductor heads, leaders, roof
         drains, and scuppers are all part of the drainage system,
         and should be included in the work list when maintenance
         or repairs are being evaluated and sched= uled for the
         gutters.


PART 2---PRODUCTS

2.01 MATERIALS

    A.   Liquid bleach:

         CAUTION:  DO NOT MIX AMMONIA WITH CHLORINE BLEACHES, A
         POISONOUS GAS WILL RESULT!  DO NOT USE BLEACH ON BIRD
         DROPPINGS.

    B.   Clean, potable water
=0C2.02 EQUIPMENT

    A.   Safety belt or harness

    B.   Ladders and scaffolding

    C.   Chicken ladder

    D.   Garden hose

    E.   Plumbers test plugs to fit the downspout conductor head

    F.   Carpenter's level

    G.   Mason's level

    H.   Chalk line

    I.   Shaped wooden or plastic paddle for scraping and sweeping


PART 3---EXECUTION

3.01 EXAMINATION

    A.   For steep roofs, inspect hanging gutters from ladders.
         Do not rest ladders on sheet metal gutte= rs.  Establish
         roof foot traffic regulations for inspec= tion of built-in
         gutters.

    B.   Check for interior deterioration which might point to
         gutter and/or roof problems.

    C.   Inspect for buildup of debris and vegetation such as moss
         or lichen.  Biological material excretes corrosive acids.
         This is apt to occur with improper gutter sloping.

    D.   Check for adequate slope and drainage towards downspouts
         during cleaning.

    E.   Make sure all downspout connections have wire strainers
         and that they are properly installed.  Strainers will
         block large debris and leaves that can block downspouts
         and sewer lines.

    F.   Inspect for gutters that are split or cracked with loose,
         broken, out of place, hangers, corners or slopes, or
         pulling of fasteners, broken joints or seams; excessive
         staining or punctures of gutter fabric.<= br>
    G.   Inspect joints frequently; Repair cracks immediate= ly.

    H.   Look for corrosion around nails.  Roof cement on gutters
         may hide leaks that have not been correc= ted.

    I.   Check for deterioration of adjacent roof and soffi= t
         areas, and behind downspouts.  Look for peeling paint or
         stains, or eroded mortar joints on adjac= ent surfaces.

    J.   Inspect the underside of the roof cornices.  = Water stains
         may be evidence of ice dams.

    K.   Install soffit ventilators in the cornice.  T= his helps
         the cornice dry out and wards off rot after the
         inevitable periodic leaks of water into the woodwork.
         Ventilators have a drawback, of course, in that by
         increasing air flow inside the cornice, they also add to
         heat loss in winter.  This can be minimized by proper
         insulation of attic spaces.

    L.   Any gutter liners made of tin, galvanized iron, or terne
         metal should be kept painted.

    M.   In addition to scheduled inspections, inspect after each
         exposure to unusually severe weather conditions such as
         strong winds, large snowfall, or long continuous rains.

    N.   Examine gutters as a part of the annual roof inspe= ction
         and repair defects immediately.  Ha= ve a competent roofer
         and plumber inspect the fabric and the joints for
         defects.  Small gutter leaks may force water into
         concealed cornice and roof areas leading to major
         defects.  

    O.   Carry out a professional survey every five years.  

    P.   In the Fall, check gutters and clean as necessary once a
         week from the time the leaves begin to fall until they
         have all fallen.  Monthly inspectio= ns are recommended
         during winter months to insure nothing impedes the flow
         of water thereby causing an ice dam in freezing weather.

3.02 ERECTION, INSTALLATION, APPLICATION

    A.   Debris removal:  Clean gutters of debris at least twice
         a year especially if surrounded by large trees, in late
         fall after all leaves have fallen; and in late spring
         after all seed pods, flowers, etc. have fallen.  Clogged
         leaders can cause water overflow and ice build-up, and
         any acidic elements at the bottom of a damp trash pile
         can eat away at the metal liner.

         1.   Sweep debris from gutters with a wood or plastic
              tool shaped to fit into radii or corners.

         2.   Remove and bag debris such as leaves, pine needles,
              branches, nests and other litter so that the gutter
              drains freely.

         3.   Where dirt or leaves lodge or normally collect in
              the gutters, it is advisa= ble to paint at yearly
              intervals.

         4.   If debris is blocking downspou= t, remove a lower
              section and flush.  = Do not allow clog to be forced
              into sewer or drainfield system.  Realign the
              gutters and downspouts.
    B.   Removing Biological Growth:

         NOTE:  ACTIVE METALS SUCH AS TIN AND COPPER DO NOT
         SUPPORT BIOLOGICAL GROWTH.

         1.   When moss, lichen, or fungus is present, wipe or
              scrape off growth.  = Use a shaped wooden or plastic
              paddle so as not to scrat= ch the surface of the
              sheet metal.

         2.   Use a 50/50 solution of liquid bleach and water to
              saturate and disinfect the areas of biological
              growth.  Brush the disinfectant solution on the
              gutters.  Keep the solution from splashing to avoid
              damage to other building material and nearby
              vegetation.

         3.   After disinfectant treatment, scrub and rinse
              thoroughly.

         4.   When this type of vegetation persists, contact the
              Regional Historic Preserv= ation Officer (RHPO) for
              assistance.

                             END OF SECTION