[Flyersfan]

new addition on house and customer wants paver patio between house and garage. about 12 feet. There is a height differential of about 12 inches between the 2 structures, so the slope will be from the house to the foundation of the garage. Was thinking I needed some drainage under the pavers (soil is heavy clay alomst all over). 3 questions

1) What type of pipe to use (how thick/sched), I assume the black corrugated stuff won't hold up)

2) Does the pipe need to exit the patio (slope so that it drains out, or just be under pavers so that excess is collected and eventually drains.

3) Should the pipe be under the geo or over. I've never understood if the geo has a sheeting quality to it when alot of water is in play (heavy downpour, potential gutter over flow in the future.. etc etc


The big worry is that with the garage foundation the water has no where to go. The dig looks like an extended "V", or checkmark , if you will...

Base is expected to be 10"

Any thoughts are appreciated

[Lawn Lad]

If you install drainage you should have it connect into something, that might be a dry well or a into an existing storm drain. If you pitch your patio away from both the house and the garage - one of the other directions, then you won't be collecting water at the garage footer.

You're mostly concerned about the surface run off, as your pavers will be intsalled with a tight joint and most water will run off of the surface with minimal percolation through the joints. If you have standing water or the grade is such that you can't avoid running it to the garage install a small catch basin and pitch the patio to the drain. If you have subsurface water issues you should consider drainage.

In which case Schedule 35 is sufficient, it won't crush when supported by the gravel. Solid pipe if you're connecting a catch basin and perforated if you're running drain tile.

[PSUscaper]

a 12" pitch over 12 ft is going to be quite awkward. I would install a step either out of the house or out of the garage first before pitching a enitire patio that much.

I really doubt you need a drain pipe under the pavers. This would be if you have a very high water table or something along those lines.

You also are most liking confusing geo grid with geo textile. Geo grid is more or less for holding back retaining walls. What you want is a good quality geo textile to put on top of that clay sub-soil before you install your stone base.

Water should be able to be diverted off of the patio to either side by giving the patio a crown as Lawn Lad touched on.

I have never heard of a V shaped dig under a patio.....you want your base and dig to be a uniform thickness for best results, meaning a level plain (well, except for the pitch required which should be no less than 1" every 4 ft, or you could use 1" every 8 ft to make it less awkward)

[cutntrim]

Originally posted by pennscapes
a 12" pitch over 12 ft is going to be quite awkward. I would install a step either out of the house or out of the garage first before pitching a enitire patio that much.

I have never heard of a V shaped dig under a patio.....you want your base and dig to be a uniform thickness for best results, meaning a level plain (well, except for the pitch required which should be no less than 1" every 4 ft, or you could use 1" every 8 ft to make it less awkward)

I was thinking the same thing, that'd be quite the sloping breezeway/patio.

[mark allen]

check with your brick rep... last I remember hearing from Unilock is that less than half a percent of water gets thru the bricks and with that much pitch ....probably less..... I agree with the step/landing idea. If you do drain into a pipe, they have some nice plastic or metal ( industrial) floor drains available, try to run it in a large french drain ( not the best option) or to daylight. Good luck.

[Flyersfan]

must be in the way I worded it. Let me try again, the grade left by the contractor that put in the addition was 12", so I'looking at a 12" graduated base.. give or take.

Doing a perk test today , and a 16" soil sample to see how far down the construction crew disturbed the soil.


Appreciate the comments

[PSUscaper]

If the contractor left a 12"deep hole, then no, you don't have a 12" base....

what you have is .....

subtract about 4 inches from that for a step into the house and garage (you most likely do not want to have a patio run flush with the bottom of a door for reason of water, snow accumulation, etc. and 4" is a prettty standard step up from a stoop or patio into a doorway), take 3 inches out for the paver thickness and 1" of bedding sand, and do the math which leaves you with about 5" of compacted base stone.

A perk test and soil sample...........this is becoming one involved patio project! Are you a engineer by any chance?

I don't want to doubt your skills or knowledge here, but this is a pretty simple project in most instances. Are you sure you don't want to just find a more experienced paver contractor to just come in and do this for you? You haven't even got this thing started and are pretty confused on how to approach this. A experienced contractor may sound expensive, but it seems like you are going to spend a LOT of time on this, and it may not come out like you expect. Maybe it would be easier to just hire someone more experienced to do this and wait for another job to come along.

[Paul]

Perk test for what???? Under a paver patio? Next a soils test but only going down 16"?????

[Flyersfan]

Actually it's not that difficult. I just wanted some advice on the type of drain pipe. Put simply, the contractor may have backfilled/disturbed the soil or filled with fill, etc. The soil sample will show it there are voids, or any construction fill (let's bury the board ends here boys, throw your cans in there, etc). The perk tst will , in the end, determine what size drain and the pitch required.

You are right though.. doing the paver work is the easy part of figure out. Base + 1 + paver depth. Everyone always says the base is the most important part. Well, fact is, the TRUE BASE is what's there before you start. So ifyou don't know your soil, it's standard makeup and performance figures .. then the 'paver base' really is a crap shoot anyway.

There will be water heading left and right, meeting somewhere in the middle-ish. That water needs to drain. Knowing the soil characteristics tells you how that water will drain.

Yes, I am an engineer. I can spec a 24 inch drain for under a major highway or runway but I don't have access to the specs on the small stuff.

[Nebraska]

Flyersfan - your profile says you are a landscape designer????

[Flyersfan]

engineer by education and primary trade, landscape design as a part time adverture with a small landscaping outfit which also does small hardscape gigs

[mark allen]

the water ain't goin' thru the bricks. If you plan on running hte drain into the soil itself....look out..... excavate the size french drain you need and build it with crushed limestone that will compact to 95% proctor. I think everyone reading this is thinking something different.....can you post a picture with elevations?

[agla]

Flyerfan,

What "C" are you using for the brick patio?

[PSUscaper]

Have you priced this job out for the 'client' yet? At this point, I'd imagine you are a 'wee' bit pricier than other contractors. Can you please explain to me how you are charging for this one?

Did you give a price already, or are you going to charge time and materials? Is the client paying you to do a soil sample and perk test? What are you charging them to have this sevice done?

I'd be, and I'm sure everyone else here would be, extremely interested in knowing how you price a job out like this one.

[Barry]

Krikey!!!

Sounds like we're not far off from footings and rebar!!!