Question
I saw you answered another question on French drains so I thought you might be able to help us.  How long could a French Drain system be expected to work assuming it was installed correctly. We live on a steep hillside with a 10 foot separation between our house and our neighbors.  Our neighbor has a French drain system installed by his father (not by a professional) 40-50 years ago.  When our house was being extensively remodeled about 5 years ago our down spouts were disconnected for several months--a period when there was probably about 10-20 inches of rain.  Our neighbor claims that this damaged his French Drain system.  During the remodeling, we replaced our system which was less than 25 years old but wasn't in good shape.  Does it seem more likely that his system was damaged during our construction or that his system has reached its end just because of its age?  Thank you.

Answer
Yes, hi Kirk. Ok, french, that of using a modern plastic piping (landflex) surrounded by large gravel and contained by builder's fleece in a trench ... will last about 30 to 50 years, if it isn't disturbed in that time!

I would imagine though that the kind of plastics used 25 years ago weren't up to scratch. Therefore, I would have given this guy's drain about 15 to 25 years.

Hope that was useful, the ratings game keeps us afloat so thanks in advance for any ratings you may give to this answer.

Regards

Jonathan www.ecologicagardens.com