How To Keep Crawl Space Drainage Lines From Freezing And Bursting

Posted on: 27 February 2015

If you live in an area where temperatures regularly dip below zero, then you may be concerned about freezing water lines. Freezing pipes can burst and cause flooding problems. Although this may be your main worry, you should also be concerned about drainage lines that freeze. This is especially true if the piping is located in an unheated crawl space. Broken drain pipes can release hazardous wastes in your home and a plumbing contractor, like C B Lucas Heating & Air Conditioning, is typically needed to make repairs. Follow the tips below if you want to keep your drains from continuously freezing.

Clear Out Your Drains

Some drains will freeze due to the residual water left within the drainage pipes after you run water or flush your toilet. If your drain lines are properly installed with the correct slope, then this may not be the problem. Inspect the drains in your home that freeze and make sure the pipes slope downward one-quarter inch to three inches every foot of PVC piping.  

If the slope is correct, then it is likely that you have food, sewage, or other types of debris stuck within the drain pipe. This debris can collect water that will expand when temperatures drop. Removing the ice and debris is your best option to stop the drains from freezing.

Removing Ice 

If your drain lines are already frozen or if drainage is extremely slow, then it is wise to remove the ice before you attack the accumulated debris. To do this, fill a five gallon cooking pot with water and place the pot on your stove. Allow the water to boil and start adding table salt to the water. Add the salt until the water is completely saturated with the sodium chloride.  

About 40 grams of salt will dissolve in 100 grams of water. This means you should be able to mix about one-third of a cup of salt to every cup of water in your pot. Once you create your hot salt water, pour it down your frozen drain. The hot water will melt the ice and the salt will lower the freezing point of the water.

If your drain does not free up for some reason an hour or two after you use the salt water, then consider pouring some calcium chloride down the drain. Calcium chloride is a deicer material that can melt ice quickly at low temperatures by pulling moisture out of the ice. The substance is safe for drains because it is not corrosive. Locate a liquid deicer solution for your drain so pellets do not cause a clog concern.

Getting Rid of Debris

If your drains have been freezing on occasion, then it is likely that the PVC materials may be somewhat weak around corners, joints, and traps. This means that you should stay away from drain cleaning or clog removal solutions that contain sulfuric or hydrochloric acids. The strong acids are likely to weaken your drain pipes further. A weak acid like the one found in vinegar is a much better choice to get rid of debris.

Pour about two cups of undiluted white vinegar in your drain. Sprinkle one-quarter cup of baking soda into the drain afterwards. The baking soda will react with the vinegar to create heat and carbon dioxide that will help loosen clog materials. About 30 minutes after you use the vinegar, run hot water  down the drain for two or three minutes. Add a few squirts of dish soap to the water as well to help loosen grease, fat, and other insoluble materials.

If you have drain lines that run through a cold crawlspace, then you may notice slow or stopped drainage during the winter. This indicates that the drains are freezing, so follow the instructions above to keep this from happening again.