Plumbing along exterior walls is prone to freezing, especially in an area that is not heated. Assuming you’ve addressed the cause of the moisture and mold in your basement, the next step is to insulate those pipes. R-value indicates insulation’s resistance to airflow, so the higher the R-value, the more effective the insulation. Each state has a different minimum R-value for walls and pipes.
Most home improvement stores carry R-4 foam pipe insulation, which should be wrapped around your water pipes. It’s important to pick the correct size for your pipes–you can choose from either ½ or ¾ of an inch. You’ll want to ensure that you cover the entire pipe, including elbows and turns. The pipes can freeze if you don’t do this. Unless there is a place in your drain lines where water stands, they are unlikely to freeze. A professional, (if you’re searching for insulation companies near me, we can help!) can tell you for sure whether or not your pipes need to be insulated.
A long term solution would be to insulate your basement walls with a closed-cell foam insulation with an R-value of 7 per inch. Adding 2 inches of thickness would yield an R-14 installed value. You’ll need to add a fire retardant coating over the foam insulation. This would insulate your pipes as well, eliminating the need for the foam pipe wrap. This can be a lot of work for the inexperienced homeowner, though, so we would recommend doing your research on insulation companies near you. You might find that we are able to do a better job for a comparable price of you doing it on your own. Contact us for a quote!