French Drain Around Garage With Patio Above - Landscaping & Lawn Care - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Landscaping & Lawn Care


Thread Tools Display Modes
Old 09-20-2012, 11:43 AM   #1
Join Date: Sep 2012
Posts: 4
Rewards Points: 10

French Drain around Garage with Patio Above

Hello. I have a unique situation (I think). My house has an attached garage with a concrete roof. The roof is also the patio when I exit out of the living room. The garage gets slightly moist when it rains. My suspision is that the rain run off from the patio is what causes this. Its a 2 car garage.

My plan is to bury my downspouts (which I think is half the problem). I will use non perforated pipe until I get away from the garage. Then I will use perforated to leach out the water into the yard.

I'm considering putting a french drain around the patio to collect the run off.

Ideas? I know slope, filter fabric, holes at the bottom etc. My question is will this catch any water coming off the patio and send it away? I only want to go down a few feet so it acts more like a gutter. I dont want to go all the way to the footer. I have read different things on how a


derzer is offline   Reply With Quote
Old 09-20-2012, 07:25 PM   #2
Join Date: Nov 2011
Location: Hartfield VA
Posts: 34,310
Rewards Points: 13,750

Sounds like a good plan.


joecaption is offline   Reply With Quote
Old 09-20-2012, 07:44 PM   #3
Concrete & Masonry
Join Date: Nov 2008
Location: Wisconsin
Posts: 3,461
Rewards Points: 582

I think you're going to want to "daylight" the pipe servicing the downspouts. Most soils won't take the load of a heavy rain from downspouts.

As for the french drain, is there any way you can have some kind of gutter installed to divert the water to the surface, away from the garage?
jomama45 is online now   Reply With Quote
Old 09-21-2012, 08:02 PM   #4
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 7,954
Rewards Points: 1,514

Originally Posted by derzer View Post
My question is will this catch any water coming off the patio and send it away? I only want to go down a few feet so it acts more like a gutter. I dont want to go all the way to the footer.)
A French drain will not protect from flooding anything below it. So to protect the garage floor from flooding you need to install the French drain below said floor level, which means down at footing level.

Instead you may want to look into a gutter that captures and channels away as much surface and patio water as possible without letting much soak into the ground near the foundation. We are not talking about gravel or sand or filter cloth or perforated; you need something solid like a molded plastic or poured concrete channel.

Next thing to figure out, where are you sending the water away to? Your system will not work if the "destination" fills up and then water backs up into said system.

In addition if the soil gets too soaked say from long and heavy rain storms, water will seep up onto your garage floor anyway. You may need a second drain system below garage floor level to capture that water, and with a destination possibly involving a sump pump.
The good conscientious technician or serviceperson will carry extra oils and lubricants in case the new pump did not come with oil or the oil was accidentally spilled, so the service call can be completed without an extra visit.

Last edited by AllanJ; 09-22-2012 at 06:37 AM.
AllanJ is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Is PVC too brittle in cold for drain under a paver patio? BrandonC_1972 Landscaping & Lawn Care 1 07-20-2012 12:18 AM
Sub-surface water; french drain bergerdude Landscaping & Lawn Care 4 04-04-2012 03:13 PM
Garage drain problem VanIps Plumbing 0 12-27-2011 08:36 PM
Installing french drain / weeping tile Troglodyte Landscaping & Lawn Care 0 05-12-2011 08:33 PM
The Bioswale, french drain, deck, drainage dilemma (long) seabright_sc Building & Construction 2 01-05-2008 03:37 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1