Rain gutters, do they really do anything?

Factual Questions
1

Ok, I’m warming up for a good gutter cleaning again this morning, and I’ve always wondered what good, exactly, do rain gutters do on a house?

The stock answer is “Well, it’s for drainage, see… All the water is bad for the foundation.”

Thinking about it, I don’t think this is really the case at all. Everywhere I’ve lived, the gutters are only on the two sides of the house where the pitch of the roof would guide the water into them. On the other two, the rainwater just falls on the ground right next to the foundation. Clearly there’s no big deal with letting the ground next to the house get wet in principle.

The two sides with the gutters concentrate the water out on the corners. There is much more water here since half the roof’s worth ends up on each side. But the downspout + splashblock only spits it out about as far as the eaves hang over anyway, it doesn’t run off from the house in any magical way once it hits the ground.

So why not just skip the stupid ugly gutters and let it spill over the edge of the eaves? I can’t see that this is any worse; arguably it’s better to distribute the water along the side rather than concentrate it in puddles at the corners.

This randomly selected link is sort of what my house looks like.

Your basic cheapo box house

Typical single story, slab built. Ours has quite generous eaves - enough to sit under in a chair and enjoy the “rain smell” without getting wet. I measured them just now at 2 feet 6 inches.

So what gives? It can’t be to protect the fascia board and roofing material, there’s no seal where the gutters meet the roof so a little water dribbles in there anyway from surface tension and the occacional “sideways rain” - plus the spikes that hold the gutters on in the first place…

Everybody has them, it seems, and nowhere I can find on the web do people question the justification. What gives? Is there a secret rain gutter cabal? Is it just so fundamental that “everyone knows” they’re necessary?

For what it’s worth I’m in the Seattle area of the US. We get a lot of rain, but seldom is it very heavy.

2

When I sided my garage at my previous house, I took down the gutters and didn’t bother putting any new ones back up for a couple of years. It didn’t take too long for a depression or channel to form at the point parallel to the garage where the water constantly fell. It damaged the ground and the grass. I later put up gutters again.

3

As Balthisar said, all the water from the house will damage the ground (ruin grass, if you have an asphalt driveway, it’ll eat away at that, the mud will spash up onto the house etc…). Also like you said it’s not good for the foundation. You asked why they don’t bother with something on the other sides as well. The reason is that on the other sides, you only have the rain that falls directly onto that section, on the sides with the gutter, you have all that rain, plus all the rain that hits the roof on that side, that’s quite a bit more. You could wind up with it making it’s way through the foundation and into the basement which will cause even more problems, not to mention overworking a sump pump if you have one. One last thing, have you ever tried to fumble with your keys and get into a house that doesn’t have a gutter over the door? Not fun.

4

When I lived in North Carolina, our house didn’t have gutters - just a metal strip on the roof above the entrance to the porch. Didn’t seem to effect much.

5

I live in a 167 year old house. For 160 years, it never occurred to the occupants of this house that if they put a gutter up on the back of the house, then water would not pour down on anyone entering the door. Further, water would not splash up onto the (low) footing underneath the back door and rot it away to non-existence. Further, that when it rained hard, the water would go someplace else besides the basement with its crummy, porous fieldstone walls. Before I put in the gutter, every heavy rainstorm would result in an inch of water in the basement. Now, that only happens if the gutter is clogged with leaves.

As it turns out, rain gutters are pretty darned useful. (And if you’re really ecologically-minded, you can always put a rain barrel under your rainspout and use the water for the garden.)

6

Oh, BTW you should have something at the end of the downspout to carry the water as far away as you can. It’s pretty common just to put another elbow at the bottom and then another three or four feet of downspout after that to carry the water away, but there are countless variations.

7

In the UK, gutters almost always dain into the water system, or municipal drains.

Not having gutters, means that water will run down the faces of the building, softening mortar, which will than need repointing much more often, walls will become damp and mouldy, window frames will rot out, as will any other woodwork. Outside walls will go green and algae ridden.

Given enough time, bricks themselves will soften and crumble, and the foundations will weaken, resulting possibly in ground movements and walls cracking.

In old houses, they had eaves that were very wide indeed, some being wide enough to shelter passers by.

8

I just had the house I’m buying inspected on Thursday, and it has no gutters. The inspector as adamant about the need for gutters and showed me a bunch of places where having gutters would have prevented problems - besides depressions in the ground and such, no gutters makes the soil settle more, which he blames in part for a few foundation cracks. (The house is 77 years old, it’s gonna have some cracks, of course.) And of course you get rained on a lot walking into the house.

9

If the roof surface is quite large, there can be quite a waterfall sluicing off the edge during a heavy shower; gutters mean you don’t have to walk through it.

Another benefit derives from channelling the water down into the sewers, helping them to flush through properly.

10

That depends alot on where you are, in some cities it’s illegal to have them drain directly into the sewers. My FIL was telling me that years and years ago the city came around and checked everyone’s downspouts, if you had them draining to the sewer they cut it off and filled it with concrete. The reason being that it was adding alot of extra water into the system and the waste treatment plant had a hard time keeping up.

11

Directing runoff straight to sewers can also be a problem in Britain. I’ve no idea of the specifics of how it works, but I’ve dealth with enough of the resulting paperwork to know that it’s a real issue!

12

I can attest from personal experience that gutters make a HUGE difference in directing water away from your foundation.

When we moved into our house it had no gutters. Every time we got heavy rain, the water would pour off the roof in sheets and pool on the ground alongside the house. Eventually the water would fill up the window well of our basement window and seep in around the window frame. We would wind up with puddles of water on our basement floor and dirty trails down the wall where the water had come in.

We put up gutters and had the downspout direct the water about 10 feet away from the house where the ground starts to slope away from the foundation. Problem solved, and further water damage averted.

We eventually had the inevitable leaves clogging up the gutters, but I put on some cheap gutter screens from Home Depot and they work like a charm. I haven’t had to clean gutters since I put the screens on five years ago.

13

Here is another voice added to the pro-gutters chorus. Letting rain water just run off the roof, saturating the ground around the foundations is just asking for trouble and structural damage.

As far as the “where does the water go” question is concerned, in towns and cities it eventually, one way or another, goes to the storm sewers. That is where it is supposed to go and no one cares if it gets there by flowing over the ground surface of by pipes to the curb.

What causes trouble is when gutters and foundation sump drains are tied into the sanitary sewer by tapping into the lines that serve toilets, sinks, washing machines, etc. If surface water is piped to the sanitary system it means that every little rainstorm will over whelm the town sewer plant and it will be forced to release raw and partially treated sewage to make room for the glut of surface water coming in to the plant. Around here it is unlawful to drain surface water into the sanitary sewer. If you ever say the raft of shredded toilet paper, condoms, sanitary napkins floating out of the sewer plant out flow after a heavy rain you would not have any questions about it

14

Gutter cleaning went fairly well yesterday. I can definitely attest that gutters help the ecology - there were a huge number of baby earwigs living in the leaves and twigs.

After I cleaned one spot in particular where there was a huge deposit of the little buggers and had moved a dozen feet or so down, a sparrow came up, perched on the gutter, and looked down where the earwigs used to be, then cocked his head at me. His expression before he flew off was: “Hey, WTF? Save some for the rest of us, eh?”

Anyway, after a little more searching and reading it sounds to me like the gutters are needed only if the site drainage is otherwise fairly poor (and then, they only help if done right). This link is quite informative, it describes a lot of what has been posted in this thread.

Clear concise summary of common drainage problems

I mean, c’mon - if Finagle can get use out of his house in Boston after 160 years without a back gutter (and Zsofia half that) I’d have to say that sort of falls on the side of suggesting that gutters might not be all that necessary. All buildings will decay with time - that’s just inevitable.

Around here, most of the homes have been standing easily 30+ years since being built, and the setup where the gutter downwash lands right next to the foundation at the corners is the norm.

According to the reference above, this is actually worse than no gutters at all, and I would agree. Ergo, if a majority of gutter installations are exacerbating the problem of water runoff and the predicted dire consequences are still rare, then it seems that rain gutters have more to do with superstition than engineering.

Not to say that I’m going to tear them off of my house tomorrow or anything, but if I build my next, I’m going to spec it out with wide eaves and no gutters (except a diverter or two for the doors).

15

I just added gutters to the back of my house. It had gutters on the front, but not the back, when we bought it.

The water off the back of the house would fall, hit the wood deck, and splash back up onto the hardboard siding on the house. 18 years of this led to the siding absorbing a lot of water, until it was crumbling, and we actually had mushrooms growing out of it. Yes, gutters would have prevented all that water splashing back up onto the house.

16

To get to my front door, I have to pass below a place fed by a valley on the roof.

Without gutters (removed when I redid the roof) I’d get soaked getting into the house. Restoring the gutters was a priority.

17

You’re not the guy who had to replace the rotted footing under the sill of the rear door of my house. It was bad enough so that I could pull it out with my bare hands, and extensive enough so that the cat could have gone in and out of the house without the door being opened. All caused by water pouring off the roof, bouncing off the wood step, and seeping under the sill.
When you’re a homeowner, you suddenly realize that water is your Enemy. About 90% of the maintenance you do as a homeowner (roof, caulking, glazing, painting, and so on) is designed to keep water out. It may be that buildings will inevitably decay, but when you’re footing the bill for the repairs, delaying the inevitable is mighty desirable.

I admit that wide eaves and careful attention to drainage would help tremendously, but those things didn’t occur to the builders of my house either.

18

With rain gutters you can also direct the runoff into a tank. Ever wash your hair in rainwater? The best water around. Also, using rainwater for your indoor house plants is another bonus. I’m betting you could put a dent in your own water bill if you watered your garden from tanked rainwater.

Finally, while living in Oz we used rainwater all the time for drinking, even when we lived in the Big Smoke where the house was connected to the mains.

19

If we in the UK kept our houses for a mere 160 years, perhaps we might not bother with gutters either.

100miles in the UK is a long way, 100 years in the US is a long time.

20

If I may add one more reason to the chorus;

If you have a basement with windows and “window-wells” (where part of the window is a bit below ground level) in heavy rain, without gutters, rain dripping directly down off the roof can fill the window well and run into your house through the window. We had that happen once when the downspouts got plugged. Not nice. The OP’s house does not appear to have that situation, but for many others here in the Northeast US its a real possibility.