# Will gravel around house help drainage?



## LawnGuyLandSparky

Making a waterproof barrier 2-4' off the foundation isn't going to stop water from being absorbed by the soil around that edge, and then working it's way towards it. You can't keep the soil "dry" it will always hold moisture. Shrubs and such do not attract or cause moisture problems. Neither does mulch.


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## compiled

Thanks for the reply.

I realize I can't keep things 100% dry and trying to do so would be a wasted effort but it still seems like rain soaking into the ground at 2' from the foundation would be better than rain soaking into the ground starting at the foundation. But maybe it makes no difference? Or not enough difference to bother?

Having a stucco home I'm not all that concerned with mulch holding moisture (which it will do) and attracting pests but it can't hurt (I don't think) to keep that moisture away from the house.

Or am I crazy?


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## KUIPORNG

*The key is Grade which you didn't mentioned*

I believe the key to water proof a house is have Grade properly to direct water to away from the house to an exhaused vent on the street which has underground pipe system. 

so did you have that in your case?

The grade should be those before you put rock on it, that is the soil ground....unless you put interlock... then the surface of the interlock dictate the grade....


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## compiled

The grade did slope towards the house but I had it pulled back and now it slopes away and towards swales that route the water around the house. Much like what is shown here http://acehomeinspec.com/images/Swales2.jpg. I imagine (or at least I hope) this will remedy the majority of the drainage / wet crawlspace issues.

My thought with the gravel is that it would add a little extra assistance directing water away from the house. That and it seems like people generally prefer or recommend not mulching or planting right up next to your house.

I'm just not sure if this is really going to help or is necessary.


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## wsuswim147

I think the gravel will have an oppsite effect of what you want. The gravel has much greater permeability than the surrounding soils. This will allow water to travel and hold (like a "bathtub") in the gravel while it is slowed down by the lower permeable soils that surround it. Grading away from the house works best, however if you really want to try and reduce water infiltration or "bathtubing" against your foundation, use compacted clay soils and then topsoil/dirt at the surface sloped away.


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## LawnGuyLandSparky

The grading will redirect excess rainwater away from the house. It will not change anything that is occuring underground where the soil meets the foundation. Mulch holds moisture in the soil and prevents it from readily evaporating as when the soil meets the sky, it will not "attract" more moisture towards it and it's miniscule effect on a wet basement/foundation problem isn't worth consideration. Regrading and directing roof runoff away from your foundation are great 1st steps. But do not ever expect that an 18" crawlspace is going to becopme, or even needs to be, bone dry. If excessmoisture is that much of a problem, consider venting the crawlspace.


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## compiled

All, thank you for the replies. From what I've gathered it sounds like my gravel idea is not necessary. I was on the building science website and they had some nice illustrations showing a layer of impermeable clay soil, like you describe wsuswim. I did find an illustration and brief mention of using a 10 mil (min) polyethylene barrier extending out from the foundation wall but they are talking about it being a foot under the soil and 6' to 10' out from the foundation wall. I'm not about to do that much excavating.

I didn't consider the bathtub effect but, that's a good point. While I'm sure it could be designed so the water could weep out or would drain off with the gravel and barrier sitting higher than its surrounding... it's not looking like it would be worth the effort or necessary. The layer of compacted clay soil is going to do the same thing.

As far as whether to use mulch or gravel in general, I haven't found any real definitive answers. I've found a lot of resources / people saying not to mulch right next to the house for pest and fire reasons and others' saying it makes no difference. Not sure what I'll do yet.


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## HomeInsulation

*Proper Drainage Around Houses*

The best way to stop water from accumulating in your basement or crawlspaces is to direct it away from your house with grading and drainage.

Connecting 4" PVC drainage pipe to the downspouts helps you control the majority of the water that comes off your roof and down through your gutters. You can dig trenches to run the PVC drainage pipe under ground.

Directing the water into french drains, dry wells, or to the public sewer system will keep the water from getting into your basement. Grading the soil around your foundation will also help. 

It's not as hard or expensive as you might think. The PVC pipe is only $7.55 for a 10 ft. long pipe at the HD or Lowes.


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## user1007

You cannot drain downspouts directly to say a street sewer system in most places I have lived and worked recently. The load on the sewer system is just too extreme. 

As for whether the OP needs gravel? I suspect not. Water is heavy and finds the lowest point. It sounds like he graded the site properly.

And you can plant near the house. Just be respectful of the plant material and plant it not for what it looks today but what it is going to grow into. And think about your maintenance over the years. You really should not have to wack have a hedge or shrub off just to get behind it to paint the house or replace a window?


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## Larry_B

" Connecting 4" PVC drainage pipe to the downspouts helps you control the majority of the water that comes off your roof and down through your gutters. You can dig trenches to run the PVC drainage pipe under ground."
This depends on where you live. Here in Montreal, Canada with ground frezing, pipes leading from downspouts into the ground are susceptible to heaving and craking which is not necessarily noticeable until the problem becomes severe.
If your area experiences freezing, it is better, to direct downspouts away from the foundation than into the ground, as per Canadian national building norms.


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## Nealtw

Larry_B said:


> " Connecting 4" PVC drainage pipe to the downspouts helps you control the majority of the water that comes off your roof and down through your gutters. You can dig trenches to run the PVC drainage pipe under ground."
> This depends on where you live. Here in Montreal, Canada with ground frezing, pipes leading from downspouts into the ground are susceptible to heaving and craking which is not necessarily noticeable until the problem becomes severe.
> If your area experiences freezing, it is better, to direct downspouts away from the foundation than into the ground, as per Canadian national building norms.


If your pipes are sloped there is no water to freeze


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## Larry_B

Because the ground surrounding the pipes will freeze and heave, they can end up separating/ breaking the pipe and blocking the flow with surrounding dirt. Subsequently, 2 things may happen:
1. water seeps into the ground and adds to the hydro-static pressure against the foundation, and/or
2. With sustained cold temps, the water coming down the downspout freezes up the pipe and cracks it.


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## Nealtw

Larry_B said:


> Because the ground surrounding the pipes will freeze and heave, they can end up separating/ breaking the pipe and blocking the flow with surrounding dirt. Subsequently, 2 things may happen:
> 1. water seeps into the ground and adds to the hydro-static pressure against the foundation, and/or
> 2. With sustained cold temps, the water coming down the downspout freezes up the pipe and cracks it.


Fair enough with the ground heave.

But your #2, sustained cold spells. There is no liquid water.


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## Larry_B

I guess you have to live here to experience it.

Water from the roof during freezing temps will result from: 
- Poorly insulated / vented roofs resulting in heat transferring to the roof and causing run-off.
- Dark asphalt shingles heat up on sunny days causing runoff to gutters.
- Some people install heating elements to prevent snow and ice buildup near the edge of the roof.

Besides the sustained cold temps we can get wild swings in temperature where it may go up to +10C during the day and dip down to -10C (or less) at night.


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## 47_47

Larry, So you know you are replying to a 6 year old thread and the op probably has his drainage fixed by now or has floated away.:smile:

Welcome to the forums!


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## stillatit

I know this is an old thread but it's right in line with my problem. 

What if I do not want to use rain gutters? I was thinking of doing the same thing as the OP but more to keep soil from eroding from around my foundation. I had put on rain gutters when we first moved in in 2000. They did their job but looked awful, dominating the front of the house. I had to remove them before a new paint job. Now my house looks so much better without the gutters. And I was thinking a barrier with 2" of stone on top, graded away from the foundation, though there isn't much of a grade, would keep the rain from the roof from washing away the soil. I have very little grade around my 1928 home because it was built before the streets and alley were put in. Luckily we don't get too much rain here in Southern California. Very few of the old houses in my neighborhood even have rain gutters.

I'll see about a photo sharing site to post pics if that helps. Unless my idea is no good to begin with.


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## stillatit

Just to add too, I looked into a French drain in front and we don't have enough of a grade to be able to bury it and have it flow. With the gravel idea I'm pretty much counting on the rain water moving from my drip line to the grass in my front yard. If that makes sense.


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## Bondo

> With the gravel idea I'm pretty much counting on the rain water moving from my drip line to the grass in my front yard.


Ayuh,.... It'll work,..... But,....
Only if the dirt grade _Below_ the stone is pitched _Away_ 1st,....

The stone might slow the erosion, but won't carry water away,....


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## stillatit

Bondo said:


> Ayuh,.... It'll work,..... But,....
> Only if the dirt grade _Below_ the stone is pitched _Away_ 1st,....
> 
> The stone might slow the erosion, but won't carry water away,....


Yeah, it will be pitched and extend out about 40" until it meets my lawn. We have plans later for more landscaping. When we have the money to get a pro in, maybe we can come up with a better solution. I'll be happy if this works for just this winter and spring.


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