How to actually keep your underground downspouts from freezing

By Tom •  Updated: 12/04/22 •  5 min read

Buried downspouts can be a necessity or a preference depending on your house. The problem is it’s possible for them to freeze. Particularly if you are WAY up north and the cold is… aggressive. 

Do underground downspouts freeze? 

Yes, they do freeze. But it all depends on where the frost line – how low below ground level the ground freezes – is for your area, how cold it gets (under 20 degrees Fahrenheit), and for how long it’s below freezing. 

If you live in a cold climate, the frost line will be between 3 and 4 feet below ground level. To be sure that your downspouts don’t freeze, they should be buried lower than 4 feet. If you live in a warmer climate you still may have frozen downspouts due to the likelihood of them not being buried deep enough or not being insulated sufficiently – if you have an unseasonably cold spell, they could freeze. 

Elbows in downspouts are prime spots for freezing due to the pooling of water in those spots. 

Related: Icicles + Ice Dams on Gutters: Causes, Prevention, Removal

How to keep buried downspouts from freezing

Assuming your downspouts are not buried below the frost line, what options do you have? 

How to fix a frozen underground downspout

Okay, say it’s too late, your buried downspout pipe has frozen and it’s too late to implement any of the measures above. Here are your options: 

  1. Run warm water UP from the bottom. Insert a hose at the bottom of the runoff and run water up to the ice by pushing the hose up as far as it will go. This will melt the ice from the bottom up and will keep the water from backing up into your house. Because if you start pouring hot water DOWN the pipes it will back up as the hot water works to melt the ice. 
  2. Pour hot water down the downspout to gradually melt the ice. This can work if the ice blockage isn’t too thick and if you aren’t able to run hot water up from the bottom as suggested above. 
  3. Disconnect the downspout to the underground downspout portion – to stop the water from continuing to melt, getting stuck, and backing up into your house or foundation due to a blocked underground pipe. You’ll want to divert the water away from your house so you could get some temporary PVC or corrugated piping to divert it far enough away from your foundation.
    1. Along these lines you should also have a gap or vent between the downspout and the underground pipe in order to allow water to flow out even if the underground pipe is frozen. Either something like this debris strainer (Amazon) or this clean out assembly combo (French Drain Man)

And this creative fellow threw everything at it and it took him all day! Hot water, hose in the underground pipe, and his wife’s hairdryer: 

How bad is it to have frozen buried downspouts? 

The primary issue is that when ice fills up and backs up gutters leading to flooding or seepage in your house and basement particularly as the snow and ice start to melt on sunny days.

If the ice gets too heavy, it could also damage gutter and downspouts.


A few years ago I bought my first house. It’s 100 years old. It’s clearly had a history of less-than-professional DIY handymen/women. And APPARENTLY you’re supposed to actually put work and money into it if you don’t want it to look terrible or water to rain down on you while you’re sleeping. About YouTube Facebook Twitter Pinterest Instagram