When Pipes Sweat: Causes and Cures For Sweating Pipes

Updated on August 28, 2011
The PEX tubing and brass ball valve are sweating substantially in a basement that the building owner wants to finish but can not until this issue is corrected.
The PEX tubing and brass ball valve are sweating substantially in a basement that the building owner wants to finish but can not until this issue is corrected. | Source

In hot summer months, it is not uncommon to find the pipes sweating in basement and crawlspace areas. This issue, while common, is typically not addressed because it is considered fairly normal. The issue that does arise, however, is that over the years, the moisture breaks down the integrity of the plumbing, connections, and valves. Furthermore, if the space is finished, there is enough moisture to promote mold growth and that can greatly affect the air quality of the building. There are some simple fixes to prevent excess moisture, but it also depends on the cause of the moisture.

Moisture Causes on Plumbing Pipes

Sweating pipes often occur in the summer time. In this case, the PEX tubing is made primarily of a plastic material while the manifold or main supply line that the pipe connects to is made of copper. The cold water coming out of the pipe causes the pipe to conduct the cold energy from the water to the walls of the pipe. The warmer air temperature and excess humidity in the air meet with the cold walls of the pipe through the process of convection and condensation begins to form, sometimes in large enough amounts to leave puddles on the floor or, in this case, a water trail (see picture below).

In the wintertime, pipes can sweat for the same reason, except that it is typically the hot water pipes rather than the cold water pipes. While this is less common, it does happen and is typical in crawlspaces where the pipes are close to the perimeter of the building. This is a good indication of a poorly insulated and air sealed basement or crawlspace but could also be an indication that the water heater temperature is higher than is typical causing a larger temperature differential between the air and the pipes.

Trail of water from sweating plumbing pipes.
Trail of water from sweating plumbing pipes. | Source

Curing Sweating Pipes

Curing sweating pipes is fairly simple as all you are really doing is preventing the convection process from occurring on the surface of the pipe. This can be accomplished by installing a pipe insulation material. There are a few different types of pipe insulation material available on the market.

Polyurethane Foam Pipe Insulation

This type of insulation is typically black and comes 4-6 foot lengths. The center of the pipe wrap is slit to allow to easy installation over the pipes and can easily be cut in order to fit varying lengths. This insulation material equates to roughly and R-4 and is usually sufficient enough to prevent pipes from sweating.

Fiberglass Pipe Wrap

Fiberglass pipe wrap is spun fiberglass wool that comes in a flat roll with a polyethylene vapor barrier attached to the back of it. The wrap is laid on top of the pipes that you want to insulate and is wrapped and tapped so that the insulation encapsulates the pipe. Plastic elbows can be purchased also to continue the insulation along the pipes, creating a complete pipe insulation system. Another variety of this insulation system is a fiberglass encapsulation with a more rigid polyurethane based exterior vapor barrier giving the pipe insulation more rigidity and cleaned joint connections. The R-value ranges from R-4 to R-12 depending on the size and style of pipe wrap.

Polyurethane Spray Foam Pipe Wrap

While this is strictly a commercial type of system, it can be used for residential use also. A plastic shell is installed over the pipes that is a clear material. The polyurethane foam is either poured or sprayed into the shell expanding and completely encapsulation the pipe. This system is very effective and is also the most costly. The typical R-value of these systems is R-7 to R-14, but can be customized into higher R-value applications for commercial use.

Sweating pipes are a typical issue in buildings around the world. Do not panic when you see this as a few hundred dollars is usually more than enough to fix the issue. If you are not sure if the pipes are sweating or leaking, dry the pipes with a cloth and monitor the area/areas in question. If water droplets are forming on the edges of the pipe joints, you may have a leak. Otherwise, it is most likely just sweating pipes and some pipe insulation will rectify the problem.

Questions & Answers

    Comments

      0 of 8192 characters used
      Post Comment

      • profile image

        dan 

        9 months ago

        best way to picture it is the soda can theory what happens on a hot summer day when you pull a cold drink out of the fridge... condensation it's the same thing with anything if it's cold on the inside and has warm air or vice versa there will be condensation it happens a lot with duct work with poor insulation or not correct r value for the area it's in

      • profile image

        ed 

        14 months ago

        Just went through something like this. Heard a water drop but could'nt figure from where. Checked the shower head, under the bathrom sink and nothing. Then early morning on my way to the restroom I hear it again. Look up at the hallway ceiling and BAM! There it is. It was the condensation pipe leaking. Rgh!

      • profile image

        Ron Jeremy 

        15 months ago

        I'd be happy to help with your education, email me.

      • Simone Smith profile image

        Simone Haruko Smith 

        7 years ago from San Francisco

        I had never heard of sweaty pipes before, but then again, I am not familiar with pipes in the least! Thanks for sharing some solutions to the problem and going over the major insulation materials. Great Hub!

      working

      This website uses cookies

      As a user in the EEA, your approval is needed on a few things. To provide a better website experience, dengarden.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

      For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://dengarden.com/privacy-policy#gdpr

      Show Details
      Necessary
      HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
      LoginThis is necessary to sign in to the HubPages Service.
      Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
      AkismetThis is used to detect comment spam. (Privacy Policy)
      HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
      HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
      Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
      CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
      Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
      Features
      Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
      Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
      Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
      Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
      Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
      VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
      PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
      Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
      MavenThis supports the Maven widget and search functionality. (Privacy Policy)
      Marketing
      Google AdSenseThis is an ad network. (Privacy Policy)
      Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
      Index ExchangeThis is an ad network. (Privacy Policy)
      SovrnThis is an ad network. (Privacy Policy)
      Facebook AdsThis is an ad network. (Privacy Policy)
      Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
      AppNexusThis is an ad network. (Privacy Policy)
      OpenxThis is an ad network. (Privacy Policy)
      Rubicon ProjectThis is an ad network. (Privacy Policy)
      TripleLiftThis is an ad network. (Privacy Policy)
      Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
      Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
      Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
      Statistics
      Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
      ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
      Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)