Expert: Bruce E. Johnson - 5/16/2009

Question
When constructing a raised patio against a house when the height of the patio is taller than the foundation, besides building a wall infront of the house to hold the gravel and keep moisture away from the house, is there other material you can use to successfully keep moisture away from the house without building the inside wall that will never been seen?

Answer
Hi Val, you can catch the water in a drain of some sort and shuttle it off to the side..you can get slotted drain tile or plastic decorative drains that will collect the water.  Another method is called a French Drain where you have some isolated rock buried in a trench with a perforated drain pipe to catch the water.  You kind of refer to something similar in your question but what you are talking about is more like a footing drain, used to keep water from the foundations of retaining walls etc.   Railroad ties make a good cheap retaining wall also..pin them to the ground with rebar cover the inside with landscaping paper or drain filter cloth..stack your rock and perf pipe footing draing against the cloth..cover this with cloth..and then back fill with soil.....I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com