Can Plumbing be on an Exterior Wall?

Home inspectors are required to inspect the plumbing in accordance with the InterNACHI Standards of Practice.

 

There are two construction practices related to plumbing pipes and insulation that are useful for home inspection inspectors to know about:

 

  • All tubes located on the outside walls should be insulated.
  • All supply pipes for hot and cold water should be isolated.

 

It should be avoided to locate water pipes in the exterior walls. If, in addition to insulating the pipe, pipes are located in external walls, the homeowner should ensure that between the pipe and the outer surface of the wall as much cavity insulation as possible is installed. Pipes in unheated attics should be avoided in colder climates. Uninsulated water supply pipes in an unconditioned basement are shown in the illustration above.

 

By reducing heat loss through the piping, insulating water pipes can save energy. Insulating pipes reduces the chance of condensation forming on them, which can cause mold and moisture damage. In the winter, pipe insulation can protect the pipes from freezing and cracking, which can cause significant damage to the walls of the home and result in substantial home repair charges for the homeowner. Distribution heat loss in uninsulated hot water pipes can range from 16 percent to 23 percent, depending on the climate, according to studies by the Department of Energy’s Building America program. The addition of 3/4-inch pipe insulation can reduce the total energy use of water heating by 4 percent to 5 percent annually.

 

Water pipes should not be located in exterior walls or in unheated attics as much as possible. Plumbing fixtures should be aligned with the interior walls whenever possible. Pipes should be insulated if they are located in exterior walls. The wall cavity containing the pipes should be air-sealed by coating or foaming all the seams between the back wall of the cavity and the framing and sealing any holes through the framing for the piping in order to further protect the pipes from heat loss. Furthermore, cavity insulation should be installed behind the pipes, as well as between the pipes and the exterior wall.

 

Heat loss can be reduced by up to 90% by insulating the steam distribution and return pipes in a house with a hydronic (steam or hot water) heating system, resulting in a quick payback on investment.

 

Pipe Insulation

Tubular pipe sleeves, spiral insulation wrap, and fiberglass batts that can be taped around the pipes are all examples of pipe insulation. All three can be effective if installed properly.

 

Tubular pipe sleeves are made of flexible polyethylene or neoprene foam closed-cell and come pre-cut for easy installation with a longitudinal seam. Some pipe covers come with adhesive strips that are already adhered to the slit on both sides. The plastic coverings can simply be peeled off by homeowners and pressed together. To accommodate the different sizes of pipes, there are different diameters of sleeves available, so it is important to measure the pipes before buying the sleeves and match the outside diameter of the pipe to the inside diameter of the pipe sleeve to ensure a snug fit.

 

Fiberglass, foil, or polyethylene foam can be made up of spiral insulation wrap. Unroll the material and wrap it around the hot and cold water pipes as needed by the homeowner. Fiberglass insulation can also be used to wrap pipes. The fiberglass insulation may include a vapor barrier on one side, or the plastic can be purchased separately and wrapped around the pipes after the fiberglass is installed. When installing fiberglass insulation, gloves, goggles, and a dust mask are recommended.

 

How to Insulate Pipes Using Tubular Foam Sleeves

  • Cut the length of the pipe sleeve and wrap it around the pipe, facing the slit downward, making sure there are no gaps between the sleeves. Make a joint at the elbow and angle the foam ends to form a mitered corner that fits the angle of the pipe to cover bends in the pipe.
  • The paper strips covering the self-sealing, pre-glued seam are removed and the edges are pressed together.
  • Tape acrylic or aluminum foil tape over the seams and joints to make them more durable.
  • To secure the isolation (and plastic covering) to the pipe every 1 to 2 feet, use wire, tape, a plastic tie, or metal clamp.
  • Use caulk or foam to seal any holes in which walls, floors, ceilings or framing are penetrated by pipes.
  • If pipes run through exterior wall cavities, insulate them just like the other cavities with blown cellulose, fiberglass, or spray foam, which will easily fill in the gaps behind the pipes. Split the batt lengthwise when you install fiberglass or mineral wool batts. Fit the batt into the cavity by sliding half of it behind the pipes. Fill the cavity with the remaining batt by placing it in front of the pipes. Alternatively, cut a piece of rigid foam to match the dimensions of the wall cavity. To seal the foam to the back wall of the cavity, run a bead of foam adhesive around the back of it, slide it behind the pipe, and press it into place. Air-seal the edges of the cavity framing with caulk or canned foam. Over the pipes, lay a split batt.

 

How to Insulate Pipes Using Spiral Wrap or Fiberglass Batts

  • Secure with tape to the end of the spiral wrap or fiberglass batt on the pipe.
  • In a spiral fashion, wrap the insulation around the pipe, overlapping each successive layer with a tape 1⁄2-inch or half the width of the batt insulation. Because compressing the batts reduces their R-value, wrap them as loosely as possible.
  • Wrap plastic around the insulated pipe and tape it to keep the insulation from getting wet if you’re installing fiberglass insulation without a moisture barrier.
  • To secure the insulation (and plastic covering) to the pipe every 1 to 2 feet, use wire, tape, a plastic tie, or metal clamp to keep the insulation from sliding out of place.
  • Use caulk or foam to seal any holes in which walls, floors, ceilings or framing are penetrated by pipes.
  • If pipes run through exterior wall cavities, insulate them just like the other cavities with blown cellulose, fiberglass, or spray foam, which will easily fill in the gaps behind the pipes. Split the batt lengthwise when you install fiberglass or mineral wool batts. Fit the batt into the cavity by sliding half of it behind the pipes. Fill the cavity with the remaining batt by placing it in front of the pipes. Alternatively, cut a piece of rigid foam to match the dimensions of the wall cavity. To seal the foam to the back wall of the cavity, run a bead of foam adhesive around the back of it, slide it behind the pipe, and press it into place. Air-seal the edges of the cavity framing with caulk or canned foam. Over the pipes, lay a split batt.

 

How to Insulate Steam Pipes

Boiler surfaces, steam and condensate return piping, and fittings should all be insulated if the temperature exceeds 120°F.

 

  • Measure the length of the pipe you are insulating and cut the matching fiberglass sleeve. Because other types of insulation can melt, use 1-inch thick, high-density, resin-bonded fiberglass sleeves approved for steam or hot water heating systems.
  • By pulling on the release strip, the pre-cut fiberglass sleeve opens.
  • Align the self-sealing lap over the sleeve and fit the sleeve around the pipe.
  • To secure the lap to the sleeve, seal it by firmly rubbing on the adhesive strip.
  • Wrap high-temperature tape around the pipe at the junction of two sleeves.
  • On elbows, tees, and other pipe fittings, install removable insulation jackets.
  • Use caulk or foam to seal any holes in which walls, floors, ceilings or framing are penetrated by pipes.
  • If pipes run through exterior wall cavities, insulate them just like the other cavities with blown cellulose, fiberglass, or spray foam, which will easily fill in the gaps behind the pipes. Split the batt lengthwise when you install fiberglass or mineral wool batts. Fit the batt into the cavity by sliding half of it behind the pipes. Fill the cavity with the remaining batt by placing it in front of the pipes. Alternatively, cut a piece of rigid foam to match the dimensions of the wall cavity. To seal the foam to the back wall of the cavity, run a bead of foam adhesive around the back of it, slide it behind the pipe, and press it into place. Air-seal the edges of the cavity framing with caulk or canned foam. Over the pipes, lay a split batt.

 

Summary

The installation of pipes on the outside walls should be avoided. If they must be installed in exterior walls, the homeowner must ensure that the pipes are properly insulated and that adequate cavity insulation is installed behind them. The wall cavity can be air-sealed to keep cold air from flowing around the pipes and causing freezes. All hot and cold water supply pipes should be isolated, which, by minimizing heat loss through the piping, can save energy.

 

If you feel overwhelmed and need help finding a great Local Miami Plumber, give us a call.

 

Smart Living Home Repair Services

244 Madison Avenue , #1019

New York, NY 10016

(888) 758-9103

 

 

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