You’re the Chief Engineer and you receive an emergency call on Saturday night at 10 PM. Your Assistant Chief tells you that a water pipe burst on the 15th floor and water is pouring into the hallways and leaking down to lower levels. Or, you’re a homeowner and you find the washing machine has been dumping water onto the floor, flooding the room. Time to take immediate action. First things first, turn off the water. After that how do we clean this up and get the spaces back to operating condition?
Water damage can affect the integrity of the building materials, resulting in possible replacement, and can affect the health of the occupants from mold growth. An independent indoor environmental consultant such as Indoor Science can assess your building or residence to help prevent burst pipes in the first place or help guide you through a response should an event happen.
This post discusses causes of burst pipes from freezing temperatures, prevention, and response actions.
Causes of Burst Pipes
In many locations in the U.S., temperatures in the winter months drops below freezing. This can cause pipes to burst due to many factors, such as improper insulation, water flow (or lack thereof), and indoor temperatures. When water freezes, it expands and puts pressure on the walls and fittings of the pipes. This can result in a burst pipe.
Prevention of Burst Pipes
Pipes that are located on exterior or perimeter walls can be exposed to freezing temperatures. Also, pipes located in unheated interior areas, like basements, attics and crawl spaces, can also be exposed to freezing temperatures.
A few key preventative steps that can be taken to reduce or eliminate freezing pipes is to:
- Ensure that all pipes potentially exposed to freezing temperatures are properly insulated, both hot and cold lines
- Consider installing a UL-listed heat tape, heat cable, or similar product on exposed water pipes.
- Provide heat to areas where pipes are located in freezing areas. The interior temperature should be at least 55°F or warmer
- If the faucets will not be used for extended periods of time (greater than 24 hours), opening the faucet to a very slow trickle will reduce the risk of ice forming in the pipes
- Ensure that all exterior faucets (e.g. – garden hose spigots) are closed and remove and drain any hoses connected to these spigots
Responses to Burst Pipes
If a pipe bursts and building materials are impacted by water, a quick response is required to save the affected building materials and prevent the growth of mold. If building materials are impacted by water, the materials can be restored if the integrity of the material has not been compromised and mold growth has not started. But, mold growth can begin 48-72 hours after the water leak.
Identifying Moisture-Impacted Building Materials
Many building materials are porous and can absorb and retain water, affecting the integrity of the building materials. If the building materials remain wet enough for long enough, wood floors can become warped and drywall can begin falling apart. However, if the leak is found early enough and these building materials are dried quickly, they can be saved.
The moisture content in building materials is measured using a moisture meter, which measures moisture in %WME (Percent Wood Moisture Equivalent).
- <16 %WME = Building Material considered ‘Dry’
- 16 – 20 %WME = Building Material considered ‘At Risk’ for mold growth and decomposition
- >20 %WME = Building Material considered ‘Elevated’ and mold growth/decomposition will occur
Another tool commonly used to identify moisture impacted building materials is a thermal imager. The thermal imager is a very useful tool, because the moisture impacted areas may not be visible to the naked eye. When building materials are wet, they will be at a lower temperature than the surrounding ‘dry’ building materials, which the thermal imager can identify. Thermal imaging should always be followed up with a moisture meter to verify moisture content.
Restoration & Replacement
When building materials are impacted by moisture, there are two options: restoration (drying) or replacement. One very important point: repair the source of the leak before any restoration activities commence.
Restoration can be used under the following three conditions: 1) The integrity of the building material is not compromised 2) No mold growth is identified 3) The building material was impacted by potable/drinking (‘Clean’) water only.
If the water is classified as ‘Gray’ (water that may be contaminated with biological or chemical contaminants) or ‘Black’ water (water that is known to be contaminated with biological or chemical contaminants), then the building material must be replaced. Drying moisture impacted building materials can be challenging. Water restoration contractors use a variety of cleaning equipment, including water extractors, fans/blowers, and dehumidifiers.
Replacement of building materials is necessary when either the integrity of the building material is compromised or mold growth is identified. Because of the renovation activities, restoration can raise the levels of mold and dust. The restoration contractor should use engineering controls, such as air scrubbers, plastic enclosures, and coverings over the HVAC vents, which prevent mold spores and dust from migrating to other parts of the building and affecting other occupants and spaces.
Mold & Moisture Testing
Mold can cause serious health problems and steps should be taken during restoration activities to protect occupants and other building materials from being further impacted and also after restoration activities are complete to ensure that all moisture levels are low enough and all mold has been removed.
Mold testing during restoration activities may include surface testing and air testing, along with moisture measurements. Mold testing following restoration activities is necessary to ensure that all visible mold growth and impacted building materials have been removed and that the airborne mold spore concentrations are back to normal.
Leaving mold- or moisture-impacted building materials behind or leaving elevated concentrations of mold spores in the air after restoration can lead to future mold growth and also expose occupants to mold health hazards.